A 913,855
WHEWELL
HISTORY
SCIENTIFIC
IDEAS
2
Q
175
W59
1858
V.2
UNIV
OF
MICH
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GENERAL LIBRARY
W
ARTES
1817
VERITAS
SCIENTIA VE
AN
IVERSITY OF MICHIG!
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1
HISTORY
OF
SCIENTIFIC IDEAS.
VOLUME II.
W.M.
Cumbridge:
PRINTED BY C. J. CLAY, M.A.
AT THE UNIVERSITY PRESS.
HISTORY
5-162
OF
SCIENTIFIC IDEAS.
BY WILLIAM WHEWELL, D.D.,
MASTER OF TRINITY COLLEGE, CAMBRIDGE, AND
CORRESPONDING MEMBER OF THE INSTITUTE OF FRANCE.
BEING THE FIRST PART OF THE PHILOSOPHY
1.
OF THE INDUCTIVE SCIENCES.
THE THIRD EDITION.
IN TWO VOLUMES.

سسة
ΛΑΜΠΑΔΙΑ ΕΧΟΝΤΕΣ ΔΙΑΔΩΣΟΥΣΙΝ ΑΛΛΗΛΟΙΣ.
VOLUME II.
LONDON:

JOHN W. PARKER AND SON, WEST STRAND.
1858.
175
Vol. 2

175
وکی نادر
1858
112
CONTENTS
OF
THE SECOND VOLUME.
BOOK VI.
THE PHILOSOPHY OF CHEMISTRY.
CHAP. I. ATTEMPTS TO CONCEIVE ELEMENTARY COMPOSI-
Art. I.
2.
TION
Fundamental Ideas of Chemistry.
Elements.
3. Do Compounds resemble their Elements?
4. The Three Principles.
5. A Modern Errour.
6. Are Compounds determined by the Figure of
Elements?
7.
Crystalline Form depends on Figure of Elements.
8. Are Compounds determined by Mechanical At-
traction of Elements?
PAGE
9.
Newton's followers.
10.
Imperfection of their Hypotheses.
CHAP. II. ESTABLISHMENT AND DEVELOPMENT OF THE
IDEA OF CHEMICAL AFFINITY
Art. 1. Early Chemists.
2.
Chemical Affinity.
3. Affinity or Attraction?
4. Affinity preferable.
5. Analysis is possible.
•
15
vi
CONTENTS OF
PAGE
Art. 6. Affinity is Elective.
7. Controversy on this.
8.
Affinity is Definite.
9. Are these Principles necessarily true?
10. Composition determines Properties.
II. Comparison on this subject.
12. Composition determines Crystalline Form.
CHAP. III. OF THE IDEA OF SUBSTANCE
Art. 1. Indestructibility of Substance.
The Idea of Substance.
2.
3.
Locke's Denial of Substance.
4.
Is all Substance heavy?
Note on Sir W. Hamilton's objections
CHAP. IV. APPLICATION OF THE IDEA OF SUBSTANCE IN
CHEMISTRY
Art. I.
A Body is Equal to its Elements.
Lavoisier.
2.
3. Are there Imponderable Elements?
4. Faraday's views.
5. Composition of Water.
6. Heat in Chemistry.
CHAP. V. THE ATOMIC THEORY
Art. I.
The Theory on Chemical Grounds.
2. Hypothesis of Atoms.
3. Its Chemical Difficulties.
4. Grounds of the Atomic Doctrine.
5. Ancient Atomists.
6. Francis Bacon,
7. Modern Atomists.
8. Arguments for and against.
9. Boscovich's Theory.
Poisson's Inference.
IO.
Molecular Hypothesis.
II.
12.
Wollaston's Argument.
13. Properties are Permanent.
. 29
29
· 37
39
48√
THE SECOND VOLUME.
vii
BOOK VII.
THE PHILOSOPHY OF MORPHOLOGY, INCLUDING
CRYSTALLOGRAPHY.
EXPLICATION OF THE IDEA OF SYMMETRY
CHAP. I.
Art. 1.
Symmetry, what.
PAGE
67
2.
Kinds of Symmetry.
3. Examples in Nature.
4. Vegetables and Animals.
5. Symmetry a Fundamental Idea.
6. Result of Symmetry.
CHAP. II. APPLICATION OF THE IDEA OF SYMMETRY TO
CRYSTALS
'Fundamental Forms."
Art. I.
2.
Their use.
3. 'Systems of Crystallization.'
4. Cleavage.
5. Other Properties.
CHAP. III. SPECULATIONS FOUNDED UPON THE SYMMETRY
OF CRYSTALS
Art. 1. Integrant Molecules.
2.
Difficulties of the Theory.
3. Merit of the Theory.
Wollaston's Hypothesis.
4.
5.
Maxim for such Hypotheses.
6. Dalton's Hypothesis.
7. Ampère's Hypothesis.
8. Difficulty of such Hypotheses.
9. Isomorphism.
75
80
viii
CONTENTS OF
BOOK VIII.
PHILOSOPHY OF THE CLASSIFICATORY
SCIENCES.
CHAP. I. THE IDEA OF LIKENESS AS GOVERNING THE USE
OF COMMON NAMES
Art. 1.
Object of the Chapter.
2.
Unity of the Individual.
3.
Condition of Unity.
4.
Kinds.
5. Not made by Definitions.
6.
7.
8.
Condition of the Use of Terms.
Terms may have different Uses.
Gradation of Kinds.
9. Characters of Kinds.
་
10. Difficulty of Definitions.
II.
"The Five Words.'
CHAP. II. THE METHODS OF NATURAL HISTORY, AS
REGULATED BY THE IDEA OF LIKENESS
Sect. I. Natural History in General.
Art. I.
2.
Idea of Likeness in Natural History.
Condition of its Use.
Sect. II.
Terminology.
Art. 3.
Meaning of the word.
Sect. III.
The Plan of the System.
Latent Reference to Natural Affinity.
PAGE
•
95
108
Art. 4. Its Meaning.
5.
6. Natural Classes.
7. Artificial Classes.
8.
Are Genera Natural?
9. Natural History and Mathematics.
10. Natural Groups given by Type, not by Definition.
II. Physiography.
12.
Artificial and Natural Systems.
THE SECOND VOLUME.
ix
Sect. IV.
Art. 13.
Methods of framing Natural Systems.
Method of Blind Trial.
PAGE
14.
Method of General Comparison.
Sect. V.
Gradation of Groups.
Art. 15.
Series of Subdivisions.
16.
What is a Species?
17.
The words 'Species' and 'Genus.'
Races.
18.
Sect. VI.
Varieties.
Nomenclature.
Art. 19. Binary Nomenclature.
Sect. VII. Diagnosis.
Art. 20.
Characteristick and Systematick.
CHAP. III. APPLICATION OF THE NATURAL HISTORY ME-
THOD TO MINERALOGY
Art. I.
Mohs's System.
2.
His Characteristick.'
3. Mineral Species not yet well fixed.
4.
Orders of Minerals.
5. Nomenclature of Minerals.
6. M. Necker's 'Règne Mineral.'
7. Inconvenience of taking a Chemical Basis of
Mineral Systems.
8. Relation of Natural History and Chemistry.
9. What is a Mineralogical Individual?
IO.
A well-formed Crystal is an Individual.
II. Not the Integrant Molecules,
12.
Nor the Cleavage Forms.
13. Compound Crystals are not Individuals.
14. Crystalline Forms are sufficiently complete for
this.
15. Including aggregate Masses.
16. Do Artificial Crystals belong to Mineralogy?
17. The Mineralogical Individual extends as far as
the same Crystalline Axes extend.
18. Artificial Crystals do belong to Mineralogy:
138
X
CONTENTS OF
Art. 19. Cannot be excluded.
20. Species to be determined by the Crystalline
Power.
21. Secondary Derivative Forms are Varieties:
22.
Are not Species, as M. Necker holds.
CHAP. IV. OF THE IDEA OF NATURAL AFFINITY
Art. I.
2.
The Idea of Affinity
Is not to be made out by Arbitrary Rules.
3. Functions of Living things are many,
4.
But all lead to the same arrangement.
5.
This is Cuvier's principle:
6. And Decandolle's.
7.
Is this applicable to Inorganic Bodies?
PAGE
•
. 159
8. Yes; by the agreement of Physical and Che-
mical Arrangement.
BOOK IX.
THE PHILOSOPHY OF BIOLOGY.
CHAP. I. ANALOGY OF BIOLOGY WITH OTHER SCIENCES. 169
Art. 1. Biology involves the Idea of Life.
2.
This Idea to be historically traced.
•
174
3. The Idea at first expressed by means of other
Ideas.
4. Mystical, Mechanical, Chemical, and Vital
Fluid Hypotheses.
CHAP. II. SUCCESSIVE BIOLOGICAL HYPOTHESES
Sect. I. The Mystical School.
Sect. II. The Iatrochemical School.
Sect. III. The Iatromathematical School.
Sect. IV. The Vital Fluid School.
Sect. V. The Psychical School.
THE SECOND VOLUME.
xi
PAGE
CHAP. III. ATTEMPTS TO ANALYSE THE IDEA OF LIFE. . 195
Art. I.
Definitions of Life,
2. By Stahl, Humboldt, Kant.
3. Definition of Organization by Kant.
4.
5.
6.
7.
8.
9.
10.
II.
Life is a System of Functions.
Bichat. Sum of Functions.
Use of Definition.
Cuvier's view.
Classifications of Functions.
Vital, Natural, and Animal Functions.
Bichat. Organic and Animal Life.
Use of this Classification.
CHAP. IV. ATTEMPTS TO FORM IDEAS OF SEPARATE VITAL
FORCES, AND FIRST, OF ASSIMILATION AND
SECRETION
Sect. I.
Art. I.
Course of Biological Research.
Observation and New Conceptions.
Sect. II. Attempts to form a distinct Conception of Assi-
Art. 2.
milation and Secretion.
The Ancients.
3. Buffon. Interior Mould.
203
4.
Defect of this view.
5. Cuvier. Life a Vortex.
6.
Defect of this view.
7.
Schelling. Matter and Form.
8. Life a constant Form of circulating Matter, &c.
Sect. III. Attempts to conceive the Forces of Assimilation
and Secretion.
Art. 9. Assimilation is a Vital Force.
IO.
II.
The name 'Assimilation.'
Several processes involved in Assimilation,
12. Absorption. Endosmose.
13. Absorption involves a Vital Force.
14.
Secretion. Glands.
15. Motions of Vital Fluids.
xii
CONTENTS OF
Sect. IV.
Art. 16.
17.
18.
19.
20.
Attempts to conceive the Process of Generation.
'Reproduction' figuratively used for Generation.
Nutrition different from
Generation.
Generations successively included.
Pre-existence of Germs.
21. Difficulty of this view.
22. Communication of Vital Forces.
23. Close similarity of Nutrition and Generation.
24. The Identity of the two Processes exemplified.
PAGE
CHAP. V. ATTEMPTS TO FORM IDEAS OF SEPARATE VITAL
FORCES, continued.-VOLUNTARY MOTION. 222
Art. 1. Voluntary Motion one of the animal Func-
tions.
2. Progressive knowledge of it.
3. Nervous Fluid not electric.
4. Irritability. Glisson.
5. Haller.
6. Contractility.
7. Organic Sensibility and Contractility not se-
parable.
8. Improperly described by Bichat.
9. Brown.
10. Contractility a peculiar Power.
II. Cuvier's view.
12. Elementary contractile Action.
13. Strength of Muscular Fibre.
14. Sensations become Perceptions
15. By means of Ideas;
16. And lead to Muscular Actions.
17. Volition comes between Perception and Action.
18. Transition to Psychology.
19. A center is introduced.
20.
The central consciousness may be obscure.
21. Reflex Muscular Action.
22.
Instinct.
23. Difficulty of conceiving Instinct.
24. Instinct opposed to Insight.
THE SECOND VOLUME.
xiii
1
CHAP. VI.
Art. 1.
2.
4.
5.
OF THE IDEA OF FINAL CAUSES
Organization. Parts are Ends and Means.
Not merely mutually dependent.
3. Not merely mutually Cause and Effect.
Notion of End not derived from Facts.
This notion has regulated Physiology.
6. Notion of Design comes from within.
7. Design not understood by Savages.
Design opposed to Morphology.
9. Impression of Design when fresh.
10. Acknowledgement of an End by adverse Phy-
siologists.
II. This included in the Notion of Disease.
12.
13.
It belongs to organized Creatures only.
The term Final Cause.
14.
Law and Design.
L
15. Final Causes and Morphology.
16. Expressions of physiological Ends.
17. The Conditions of Existence.
18. The asserted presumption of Teleology.
19. Final Causes in other subjects,
20.
Transition to Palætiology.
BOOK X.
THE PHILOSOPHY OF PALETIOLOGY.
PAGE
. 239
CHAP. I. OF PALETIOLOGICAL SCIENCES IN GENERAL 257
Art. 1.
Description of Palætiology.
Its Members.
2.
3.
Other Members.
4.
Connexion of the whole subject.
5. We shall take Material Sciences only;
6. But these are connected with others.
CHAP. II. OF THE THREE MEMBERS OF A PALÆTIOLOGI-
CAL SCIENCE
Art. 1. Divisions of such Sciences.
•
263
2.
The Study of Causes.
3. Etiology.
xiv
CONTENTS OF
Art. 4. Phenomenology requires Classification. Phe-
nomenal Geology.
5. Phenomenal Uranology.
6. Phenomenal Geography of Plants and Animals.
7. Phenomenal Glossology.
8. The Study of Phenomena leads to Theory.
9.
IO.
II.
No sound Theory without Etiology.
Causes in Palætiology.
Various kinds of Cause.
12. Hypothetical Order of Palætiological Causes.
13. Mode of Cultivating Ætiology:—In Geology:
14. In the Geography of Plants and Animals:
15.
16.
17.
In Languages.
Construction of Theories.
No sound Palætiological Theory yet extant.
CHAP. III. OF THE DOCTRINE OF CATASTROPHES AND THE
DOCTRINE OF UNIFORMITY
Art. I.
Doctrine of Catastrophes.
PAGE
•
284
2.
3.
Doctrine of Uniformity.
Is Uniformity probable a priori?
4. Cycle of Uniformity indefinite.
5. Uniformitarian Arguments are Negative only.
6. Uniformity in the Organic World.
7. Origin of the present Organic World.
8. Nebular Origin of the Solar System.
9. Origin of Languages.
10.
CHAP. IV.
No Natural Origin discoverable.
OF THE RELATION OF TRADITION TO PALE-
TIOLOGY
Art. 1. Importance of Tradition.
2.
Connexion of Tradition and Science.
3. Natural and Providential History of the World.
4.
The Sacred Narrative.
5. Difficulties in interpreting the Sacred Narra-
tive.
6. Such Difficulties inevitable.
7. Science tells us nothing concerning Creation.
•
297
THE SECOND VOLUME.
XV
Art. 8. Scientific views, when familiar, do not disturb
the authority of Scripture.
IO.
?
9. When should Old Interpretations be given up
In what Spirit should the Change be accepted?
In what Spirit should the Change be urged?
Duty of Mutual Forbearance.
II.
12.
13. Case of Galileo.
CHAP. V. OF THE CONCEPTION OF A FIRST CAUSE.
Art. I.
2.
The Origin of things is not naturally discover-
able;
Yet has always been sought after.
3. There must be a First Cause.
4.
This is an Axiom.
5. Involved in the proof of a Deity.
6. The mind is not satisfied without it.
PAGE
•
316
7. The Whole Course of Nature must have a
Cause.
8. Necessary Existence of God.
9. Forms of the Proof.
IO.
Idea of a First Cause is Necessary.
II. Conception of a First Cause.
12.
The First Cause in all Sciences is the same.
13. We are thus led to Moral Subjects.
Conclusion of this History.

BOOK VI.
THE
PHILOSOPHY
OF
CHEMISTRY.
VOL. II.
B
A PHILOSOPHER was asked:-How much does smoke weigh?
He answered: Subtract from the weight of the fuel the weight
of the ashes, and thou hast the weight of the smoke. Thus he
assumed as incontrovertible that, even in the fire, the Substance
does not perish, only its Form undergoes a change. In like
manner the proposition, Nothing can come of Nothing, was only
another consequence of the Principle of Permanence, or rather
of the Principle of the Enduring Existence of the same subject
with different appearances.
KANT, Kritik d. r. Vern.
个
​BOOK VI.
THE PHILOSOPHY OF CHEMISTRY.
CHAPTER I.
ATTEMPTS TO CONCEIVE ELEMENTARY COMPOSITION.
I.
WH
E have now to bring into view, if possible, the
Ideas and General Principles which are in-
volved in Chemistry,-the science of the composition
of bodies. For in this as in other parts of human
knowledge, we shall find that there are certain Ideas,
deeply seated in the mind, though shaped and unfolded
by external observation, which are necessary conditions
of the existence of such a science. These Ideas it is,
which impel man to such a knowledge of the Composi-
tion of bodies, which give meaning to facts exhibiting
this composition, and universality to special truths
discovered by experience. These are the Ideas of
Element and of Substance.
Unlike the Idea of Polarity, of which we treated in
the last Book, these Ideas have been current in men's
minds from very early times, and formed the subject
of some of the first speculations of philosophers. It
happened however, as might have been expected, that
in the first attempts they were not clearly distinguished
from other notions, and were apprehended and applied
in an obscure and confused manner. We cannot better
exhibit the peculiar character and meaning of these
Ideas than by tracing the form which they have assumed
B 2
4
PHILOSOPHY OF CHEMISTRY.
-
and the efficacy which they have exerted in these suc-
cessive essays. This, therefore, I shall endeavour to
do, beginning with the Idea of Element.
2. That bodies are composed or made up of certain
parts, elements, or principles, is a conception which
has existed in men's minds from the beginning of the
first attempts at speculative knowledge. The doctrine
of the Four Elements, Earth, Air, Fire and Water, of
which all things in the universe were supposed to be
constituted, is one of the earliest forms in which this
conception was systematized; and this doctrine is
stated by various authors to have existed as early as
the times of the ancient Egyptians'. The words usually
employed by Greek writers to express these elements
are ἀρχὴ a principle or beginning, and στοιχεῖον,
which probably meant a letter (of a word) before it
meant an element of a compound. For the resolution
of a word into its letters is undoubtedly a remarkable
instance of a successful analysis performed at an early
stage of man's history; and might very naturally
supply a metaphor to denote the analysis of substances
into their intimate parts, when men began to contem-
plate such an analysis as a subject of speculation. The
Latin word elementum itself, though by its form it
appears to be a derivative abstract term, comes from
some root now obsolete; probably² from a word signi-
fying to grow or spring up.
The mode in which elements form the compound
bodies and determine their properties was at first, as
might be expected, vaguely and variously conceived. It
will, I trust, hereafter be made clear to the reader that
the relation of the elements to the compound involves
a peculiar and appropriate Fundamental Idea, not sus-
ceptible of being correctly represented by any compari-
son or combination of other ideas, and guiding us to
clear and definite results only when it is illustrated
1 Gilbert's Phys. 1. i. c. iii.
2 Vossius in voce. "Conjecto esse
ab antiqua voco eleo pro oleo, id est
cresco: a qua significatione proles, sub-
oles, adolescens: ut ab juratum, jura-
mentum; ab adjutum, adjumentum :
sic ab eletum, elementum: quia inde
omnia crescunt ac nascuntur.”
CONCEPTION OF ELEMENTARY COMPOSITION. 5
•
and nourished by an abundant supply of experimental
facts. But at first the peculiar and special notion
which is required in a just conception of the constitu-
tion of bodies was neither discerned nor suspected;
and up to a very late period in the history of chemis-
try, men went on attempting to apprehend the consti-
tution of bodies more clearly by substituting for this
obscure and recondite idea of Elementary Composition,
some other idea more obvious, more luminous, and
more familiar, such as the ideas of Resemblance, Posi-
tion, and mechanical Force. We shall briefly speak
of some of these attempts, and of the errours which
were thus introduced into speculations on the relations
of elements and compounds.
3. Compounds assumed to resemble their Elements.
-The first notion was that compounds derive their
qualities from their elements by resemblance:-they
are hot in virtue of a hot element, heavy in virtue of a
heavy element, and so on. In this way the doctrine
of the four elements was framed; for every body is
either hot or cold, moist or dry; and by combining
these qualities in all possible ways, men devised four
elementary substances, as has been stated in the His-
tory3
This assumption of the derivation of the qualities of
bodies from similar qualities in the elements was, as we
shall see, altogether baseless and unphilosophical, yet
it prevailed long and universally. It was the founda-
tion of medicine for a long period, both in Europe and
Asia; disorders being divided into hot, cold, and the
like; and remedies being arranged according to similar
distinctions. Many readers will recollect, perhaps, the
story of the indignation which the Persian physicians
felt towards the European, when he undertook to
cure the ill effects of cucumber upon the patient, by
means of mercurial medicine: for cucumber, which is
cold, could not be counteracted, they maintained, by
mercury, which in their classification is cold also.
Similar views of the operation of medicines might
4
3 Hist. Ind. Sc. b. i. c. ii. sec. 2.
4 See Hadji Baba.
6
PHILOSOPHY OF CHEMISTRY.
easily be traced in our own country. A moment's
reflection may convince us that when drugs of any
kind are subjected to the chemistry of the human
stomach and thus made to operate on the human frame,
it is utterly impossible to form the most remote con-
jecture what the result will be, from any such vague
notions of their qualities as the common use of our
senses can give. And in like manner the common ope-
rations of chemistry give rise, in almost every instance,
to products which bear no resemblance to the materials
employed. The results of the furnace, the alembic, the
mixture, frequently have no visible likeness to the
ingredients operated upon. Iron becomes steel by the
addition of a little charcoal; but what visible trace of
the charcoal is presented by the metal thus modified?
The most beautiful colours are given to glass and
earthenware by minute portions of the ores of black
or dingy metals, as iron and manganese. The worker
in metal, the painter, the dyer, the vintner, the brewer,
all the artisans in short who deal with practical che-
mistry, are able to teach the speculative chemist that
it is an utter mistake to expect that the qualities of
the elements shall be still discoverable, in an unaltered
form, in the compound. This first rude notion of an
element, that it determines the properties of bodies by
resemblance, must be utterly rejected and abandoned
before we can make any advance towards a true appre-
hension of the constitution of bodies.
4. This step accordingly was made, when the hypo-
thesis of the four elements was given up, and the doc-
trine of the three Principles, Salt, Sulphur, and Mer-
cury, was substituted in its place. For in making
this change, as I have remarked in the History", the
real advance was the acknowledgment of the changes,
produced by the chemist's operations, as results to be
accounted for by the union and separation of substan-
tial elements, however great the changes, and however
unlike the product might be to the materials. And
this step once made, chemists went on constantly
5 Hist. Ind. Sc. b. iv. c. I.
CONCEPTION OF ELEMENTARY COMPOSITION. 7
advancing towards a truer view of the nature of an
element, and consequently, towards a more satisfactory
theory of chemical operations.
5. Yet we may, I think, note one instance, even in
the works of eminent modern chemists, in which this
maxim, that we have no right to expect any resem-
blance between the elements and the compound, is lost
sight of. I speak of certain classifications of mineral
substances. Berzelius, in his System of Mineral Ar-
rangement, places sulphur next to the sulphurets. But
surely this is an errour, involving the ancient assump-
tion of the resemblance of elements and compounds;
as if we were to expect the sulphurets to bear a re-
semblance to sulphur. All classifications are intended
to bring together things resembling each other: the
sulphurets of metals have certain general resemblances
to each other which make them a tolerably distinct,
well determined, class of bodies. But sulphur has no
resemblances with these, and no analogies with them,
either in physical or even in chemical properties. It
is a simple body; and both its resemblances and its
analogies direct us to place it along with other simple
bodies, (selenium, and phosphorus,) which, united with
metals, produce compounds not very different from the
sulphurets. Sulphur cannot be, nor approach to being,
a sulphuret; we must not confound what it is with
what it makes. Sulphur has its proper influence in
determining the properties of the compound into which
it enters; but it does not do this according to resem-
blance of qualities, or according to any principle which
properly leads to propinquity in classification.
6. Compounds assumed to be determined by the
Figure of Elements.—I pass over the fanciful modes of
representing chemical changes which were employed
by the Alchemists; for these strange inventions did
little in leading men towards a juster view of the rela-
tions of elements to compounds. I proceed for an
instant to the attempt to substitute another obvious
conception for the still obscure notion of elementary
composition. It was imagined that all the proper-
ties of bodies and their mutual operations might be
PHILOSOPHY OF CHEMISTRY.
4
accounted for by supposing them constituted of particles
of various forms, round or angular, pointed or hooked,
straight or spiral. This is a very ancient hypothesis,
and a favourite one with many casual speculators in
all ages.
Thus Lucretius undertakes to explain why
wine passes rapidly through a sieve and oil slowly, by
telling us that the latter substance has its particles
either larger than those of the other, or more hooked
and interwoven together. And he accounts for the
difference of sweet and bitter by supposing the parti-
cles in the former case to be round and smooth, in the
latter sharp and jagged. Similar assumptions pre-
vailed in modern times on the revival of the mecha-
nical philosophy, and constitute a large part of the
physical schemes of Descartes and Gassendi. They
were also adopted to a considerable extent by the
chemists. Acids were without hesitation assumed to
consist of sharp pointed particles; which, 'I hope,'
Lemery says', 'no one will dispute, seeing every one's
experience does demonstrate it: he needs but taste an
acid to be satisfied of it, for it pricks the tongue like
anything keen and finely cut.' Such an assumption
is not only altogether gratuitous and useless, but ap-
pears to be founded in some degree upon a confusion
in the metaphorical and literal use of such words as
keen and sharp. The assumption once made, it was
easy to accommodate it, in a manner equally arbitrary,
to other facts. A demonstrative and convincing
proof that an acid does consist of pointed parts is, that
not only all acid salts do crystallize into edges, but all
dissolutions of different things, caused by acid liquors,
do assume this figure in their crystallization. These
crystals consist of points differing both in length and
bigness one from another, and this diversity must be
attributed to the keener or blunter edges of the dif-
ferent sorts of acids: and so likewise this difference of
the points in subtilty is the cause that one acid can
penetrate and dissolve with one sort of mixt, that ano-
ther can't rarify at all: Thus vinegar dissolves lead,
• De Rerum Natura, ii. 390 sqq.
7 Chemistry, p. 25.
CONCEPTION OF ELEMENTARY COMPOSITION. 9
which aqua fortis can't: aqua fortis dissolves quick-
silver, which vinegar will not touch; aqua regalis dis-
solves gold, whenas aqua fortis cannot meddle with it;
on the contrary, aqua fortis dissolves silver, but can
do nothing with gold, and so of the rest.'
8
The leading fact of the vehement combination and
complete union of acid and alkali readily suggested a
fit form for the particles of the latter class of sub-
stances. "This effect,' Lemery adds, may make us
reasonably conjecture that an alkali is a terrestrious
and solid matter whose forms are figured after such a
manner that the acid points entering in do strike and
divide whatever opposes their motion.' And in a like
spirit are the speculations in Dr. Mead's Mechanical
Account of Poisons (1745). Thus he explains the
poisonous effect of corrosive sublimate of mercury by
saying that the particles of the salt are a kind of
lamellæ or blades to which the mercury gives an addi-
tional weight. If resublimed with three-fourths the
quantity of mercury, it loses its corrosiveness, (becom-
ing calomel,) which arises from this, that in sublima-
tion 'the crystalline blades are divided every time
more and more by the force of the fire:' and 'the
broken pieces of the crystals uniting into little masses
of differing figures from their former make, those cut-
ting points are now so much smaller that they cannot
make wounds deep enough to be equally mischievous
and deadly and therefore do only vellicate and twitch
the sensible membranes of the stomach.'
:
7. Among all this very fanciful and gratuitous as-
sumption we may notice one true principle clearly
introduced, namely, that the suppositions which we
make respecting the forms of the elementary particles
of bodies and their mode of combination must be such
as to explain the facts of crystallization, as well as of
mere chemical change. This principle we shall here-
after have occasion to insist upon further.
I now proceed to consider a more refined form of
assumption respecting the constitution of bodies, yet
8 P. 199.
ΙΟ
PHILOSOPHY OF CHEMISTRY.
still one in which a vain attempt is made to substitute
for the peculiar idea of chemical composition a more
familiar mechanical conception.
8. Compounds assumed to be determined by the Me-
chanical Attraction of the Elements.-When, in conse-
quence of the investigations and discoveries of Newton
and his predecessors, the conception of mechanical
force had become clear and familiar, so far as the
action of external forces upon a body was concerned, it
was very natural that the mathematicians who had
pursued this train of speculation should attempt to
apply the same conception to that mutual action of the
internal parts of a body by which they are held to-
gether. Newton himself had pointed the way to this
attempt. In the Preface to the Principia, after speak-
ing of what he has done in calculating the effects of
forces upon the planets, satellites, &c., he adds, 'Would
it were permitted us to deduce the other phenomena
of nature from mechanical principles by the same kind
of reasoning. For many things move me to suspect
that all these phenomena depend upon certain forces,
by which the particles of bodies, through causes not
yet known, are either urged towards each other, and
cohere according to regular figures, or are repelled and
recede from each other; which forces being unknown,
philosophers have hitherto made their attempts upon
nature in vain.' The same thought is at a later period
followed out further in one of the Queries at the end
of the Opticks. Have not the small particles of
bodies certain Powers, Virtues, or Forces, by which
they act at a distance, not only upon the rays of light
for reflecting, refracting and inflecting them, but also
upon one another for producing a great part of the
phenomena of nature?" And a little further on he
proceeds to apply this expressly to chemical changes.
When Salt of Tartar runs per deliquium [or as we
now express it, deliquesces] is not this done by an at-
traction between the particles of the Salt of Tartar
and the particles of the water which float in the air in
9 Query 31.
CONCEPTION OF ELEMENTARY COMPOSITION. II
the form of vapours? And why does not common salt,
or saltpetre, or vitriol, run per deliquium, but for want
of such an attraction? or why does not Salt of Tartar
draw more water out of the air than in a certain pro-
portion to its quantity, but for want of an attractive
force after it is saturated with water?' He goes on to
put a great number of similar cases, all tending to the
same point, that chemical combinations cannot be
conceived in any other way than as an attraction of
particles.
9. Succeeding speculators in his school attempted
to follow out this view. Dr. Frend, of Christ Church,
in 1710, published his Prælectiones Chymica, in quibus
omnes fere Operationes Chymicæ ad vera Principia ex
ipsius Naturæ Legibus rediguntur. Oxonii habitæ.
This book is dedicated to Newton, and in the dedica-
tion, the promise of advantage to chemistry from the
influence of the Newtonian discoveries is spoken of
somewhat largely, much more largely, indeed, than
has yet been justified by the sequel. After declaring
in strong terms that the only prospect of improving
science consists in following the footsteps of Newton,
the author adds, "That force of attraction, of which
you first so successfully traced the influence in the
heavenly bodies, operates in the most minute corpus-
cles, as you long ago hinted in your Principia, and
have lately plainly shown in your Opticks; and this
force we are only just beginning to perceive and to
study. Under these circumstances I have been de-
sirous of trying what is the result of this view in
chemistry.' The work opens formally enough, with a
statement of general mechanical principles, of which
the most peculiar are these:-'That there exists an at-
tractive force by which particles when at very small
distances from each other, are drawn together;—that
this force is different, according to the different figure
and density of the particles; that the force may be
greater on one side of a particle than on the other;
that the force by which particles cohere together arises
from attraction, and is variously modified according to
the quantity of contacts.' But these principles are not
I2
PHILOSOPHY OF CHEMISTRY.
applied in any definite manner to the explanation of
specific phenomena. He attempts, indeed, the ques-
tion of special solvents 10. Why does aqua fortis dis-
solve silver and not gold, while aqua regia dissolves
gold and not silver? which, he says, is the most diffi-
cult question in chemistry, and which is certainly a
fundamental question in the formation of chemical
theory. He solves it by certain assumptions respecting
the forces of attraction of the particles, and also the
diameter of the particles of the acids and the pores of
the metals, all which suppositions are gratuitous.
IO. We may observe further, that by speaking, as
I have stated that he does, of the figure of particles,
he mixes together the assumption of the last section
with the one which we are considering in this. This
combination is very unphilosophical, or, to say the
least, very insufficient, since it makes a new hypothesis
necessary. If a body be composed of cubical particles,
held together by their mutual attraction, by what force
are the parts of each cube held together? In order to
understand their structure, we are obliged again to as-
sume a cohesive force of the second order, binding to-
gether the particles of each particle. And therefore
Newton himself says", very justly, 'The parts of all
homogeneal hard bodies which fully touch each other,
stick together very strongly and for explaining how
this is, some have invented hooked atoms, which is
begging the question.' For (he means to imply,) how do
the parts of the hook stick together?
The same remark is applicable to all hypotheses in
which particles of a complex structure are assumed as
the constituents of bodies: for while we suppose bodies
and their known properties to result from the mutual
actions of these particles, we are compelled to suppose
the parts of each particle to be held together by forces
still more difficult to conceive, since they are disclosed
only by the properties of these particles, which as yet.
are unknown. Yet Newton himself has not abstained
from such hypotheses: thus he says", "A particle of
10 P. 54.
11 Opticks, p. 364.
12 Opticks, p. 362.
CONCEPTION OF ELEMENTARY COMPOSITION. 13
a salt may be compared to a chaos, being dense, hard,
dry, and earthy in the center, and moist and watery
in the circumference.'
Since Newton's time the use of the term attraction,
as expressing the cause of the union of the chemical
elements of bodies, has been familiarly continued; and
has, no doubt, been accompanied in the minds of many
persons with an obscure notion that chemical attrac-
tion is, in some way, a kind of mechanical attraction
of the particles of bodies. Yet the doctrine that che-
mical attraction' and mechanical attraction are forces
of the same kind has never, so far as I am aware, been
worked out into a system of chemical theory; nor even
applied with any distinctness as an explanation of any
particular chemical phenomena. Any such attempt,
indeed, could only tend to bring more clearly into
view the entire inadequacy of such a mode of expla-
nation. For the leading phenomena of chemistry are
all of such a nature that no mechanical combination
can serve to express them, without an immense accu-
mulation of additional hypotheses. If we take as our
problem the changes of colour, transparency, texture,
taste, odour, produced by small changes in the ingre-
dients, how can we expect to give a mechanical account
of these, till we can give a mechanical account of
colour, transparency, texture, taste, odour, themselves?
And if our mechanical hypothesis of the elementary
constitution of bodies does not explain such phenomena
as those changes, what can it explain, or what can be
the value of it? I do not here insist upon a remark
which will afterwards come before us, that even crys-
talline form, a phenomenon of a far more obviously
mechanical nature than those just alluded to, has never
yet been in any degree explained by such assumptions
as this, that bodies consist of elementary particles
exerting forces of the same nature as the central forces
which we contemplate in Mechanics.
'
When therefore Newton asks, When some stones,
as spar of lead, dissolved in proper menstruums, be-
come salts, do not these things show that salts are dry
earth and watery acid united by attraction?' we may
14
PHILOSOPHY OF CHEMISTRY.
answer, that this mode of expression appears to be
intended to identify chemical combination with mecha-
nical attraction;-that there would be no objection to
any such identification, if we could, in that way, ex-
plain, or even classify well, a collection of chemical
facts; but that this has never yet been done by the
help of such expressions. Till some advance of this
kind can be pointed out, we must necessarily consider
the power which produces chemical combination as a
peculiar principle, a special relation of the elements,
not rightly expressed in mechanical terms.
And we
now proceed to consider this relation under the name
by which it is most familiarly known.
CHAPTER II.
ESTABLISHMENT AND DEVELOPMENT OF THE IDEA OF
CHEMICAL AFFINITY.
I.
TH
HE earlier chemists did not commonly involve
themselves in the confusion into which the
mechanical philosophers ran, of comparing chemical to
mechanical forces. Their attention was engaged, and
their ideas were moulded, by their own pursuits. They
saw that the connexion of elements and compounds with
which they had to deal, was a peculiar relation which must
be studied directly; and which must be understood, if
understood at all, in itself, and not by comparison with
a different class of relations. At different periods of
the progress of chemistry, the conception of this rela-
tion, still vague and obscure, was expressed in various
manners; and at last this conception was clothed in
tolerably consistent phraseology, and the principles
which it involved were, by the united force of thought
and experiment, brought into view.
2. The power by which the elements of bodies
combine chemically, being, as we have seen, a peculiar
agency, different from mere mechanical connexion or
attraction, it is desirable to have it designated by a
distinct and peculiar name; and the term Affinity has
been employed for that purpose by most modern che-
mists. The word 'affinity' in common language means,
sometimes resemblance, and sometimes relationship
and ties of family. It is from the latter sense that the
metaphor is borrowed when we speak of 'chemical
affinity.' By the employment of this term we do not in-
dicate a resemblance, but a disposition to unite. Using
the word in a common unscientific manner, we might
that chlorine, bromine, and iodine, have a great
say
16
PHILOSOPHY OF CHEMISTRY.
natural affinity with each other, for there are consi-
derable resemblances and analogies among them; but
these bodies have very little chemical Affinity for each
other. The use of the word in the former sense, of resem-
blance, can be traced in earlier chemists; but the word
does not appear to have acquired its peculiar chemical
meaning till after Boerhaave's time. Boerhaave, how-
ever, is the writer in whom we first find a due appre-
hension of the peculiarity and importance of the Idea
which it now expresses. When we make a chemical
solution', he says, not only are the particles of the dis-
solved body separated from each other, but they are
closely united to the particles of the solvent. When
aqua regia dissolves gold, do you not see, he says to
his hearers, that there must be between each particle
of the solvent and of the metal, a mutual virtue by
which each loves, unites with, and holds the other
(amat, unit, retinet)? The opinion previously preva-
lent had been that the solvent merely separates the
parts of the body dissolved: and most philosophers
had conceived this separation as performed by mechani-
cal operations of the particles, resembling, for in-
stance, the operation of wedges breaking up a block of
timber. But Boerhaave forcibly and earnestly points
out the insufficiency of the conception. This, he says,
does not account for what we see. We have not only
a separation, but a new combination. There is a force
by which the particles of the solvent associate to them-
selves the parts dissolved, not a force by which they
repel and dissever them. We are here to imagine not
mechanical action, not violent impulse, not antipathy,
but love, at least if love be the desire of uniting. (Non
igitur hic etiam actiones mechanicæ, non propulsiones
violentæ, non inimicitiæ cogitandæ, sed amicitiæ, si
amor dicendus copulæ cupido.) The novelty of this
view is evidenced by the mode in which he apologizes
for introducing it. Fateor, paradoxa hæc assertio.'
To Boerhaave, therefore, (especially considering his
great influence as a teacher of chemistry,) we may
(
1 Elementa Chemia. Lugd. Bat. 1732, p. 677.
IDEA OF CHEMICAL AFFINITY.
17
assign the merit of first diffusing a proper view of
Chemical Affinity as a peculiar force, the origin of
almost all chemical changes and operations.
3.
To Boerhaave is usually assigned also the credit
of introducing the word 'Affinity' among chemists; but
I do not find that the word is often used by him in
this sense; perhaps not at all. But however this may
be, the term is, on many accounts, well worthy to be
preserved, as I shall endeavour to show. Other terms
were used in the same sense during the early part of
the eighteenth century. Thus when Geoffroy, in 1718,
laid before the Academy of Paris his Tables of Affini-
ties, which perhaps did more than any other event to
fix the Idea of Affinity, he termed them 'Tables of the
Relations of Bodies;' Tables des Rapports:' speaking
however, also, of their 'disposition to unite,' and using
other phrases of the same import.
The term attraction, having been recommended by
Newton as a fit word to designate the force which pro-
duces chemical combination, continued in great favour
in England, where the Newtonian philosophy was
looked upon as applicable to every branch of science.
In France, on the contrary, where Descartes still
reigned triumphant, attraction,' the watch-word of
the enemy, was a sound never uttered but with dislike
and suspicion. In 1718 (in the notice of Geoffroy's
Table,) the Secretary of the Academy, after pointing
out some of the peculiar circumstances of chemical
2 See Dumas, Leçons de Phil. Chim.
p. 364. Rees' Cyclopædia, Art. Chem-
istry. In the passage of Boerhaave to
which I refer above, affinitas is rather
opposed to, than identified with, che-
mical combination. When, he says,
the parts of the body to be dissolved
are dissevered by the solvent, why do
they remain united to the particles of
the solvent, and why do not rather
both the particles of the solvent and
of the dissolved body collect into
VOL. II.
homogeneous bodies by their affinity?
<
denuo se affinitate suæ naturæ col-
ligant in corpora homogenea?' And
the answer is, because they possess
another force which counteracts this
affinity of homogeneous particles, and
makes compounds of different ele-
ments. Affinity, in chemistry, now
means the tendency of different kinds
of matter to unite: but it appears, as
I have said, to have acquired this
sense since Boerhaave's time.
C
18
PHILOSOPHY OF CHEMISTRY.
combinations, says, 'Sympathies and attractions would
suit well here, if there were such things.' 'Les sym-
pathies, les attractions conviendroient bien ici, si elles
étaient quelque chose.' And at a later period, in
1731, having to write the éloge of Geoffroy after his
death, he says, 'He gave, in 1718, a singular system,
and a Table of Affinities, or Relations of the different
substances in chemistry. These affinities gave uneasi-
ness to some persons, who feared that they were
attractions in disguise, and all the more dangerous in
consequence of the seductive forms which clever people
have contrived to give them. It was found in the
sequel that this scruple might be got over.'
This is the earliest published instance, so far as I am
aware, in which the word 'Affinity' is distinctly used
for the cause of chemical composition; and taking into
account the circumstances, the word appears to have
been adopted in France in order to avoid the word
attraction, which had the taint of Newtonianism. Ac-
cordingly we find the word affinité employed in the
works of French chemists from this time. Thus, in the
Transactions of the French Academy for 1746, in a
paper of Macquer's upon Arsenic, he says³, 'On peut
facilement rendre raison de ces phenomènes par le
moyen des affinités que les différens substances qui
entrent dans ces combinaisons, ont les uns avec les
autres:' and he proceeds to explain the facts by refer-
ence to Geoffroy's Table. And in Macquer's Elements
of Chemistry, which appeared a few years later, the
'Affinity of Composition' is treated of as a leading part
of the subject, much in the same way as has been prac-
tised in such books up to the present time. From this
period, the word appears to have become familiar to
all European chemists in the sense of which we are
now speaking. Thus, in the year 1758, the Academy
of Sciences at Rouen offered a prize for the best dis-
sertation on Affinity. The prize was shared between
M. Limbourg of Theux, near Liege, and M. Le Sage
3 A. P. 1746, p. 201.
IDEA OF CHEMICAL AFFINITY.
19
of Geneva¹. About the same time other persons
(Manherr, Nicolai, and others) wrote on the same
subject, employing the same name.
Nevertheless, in 1775, the Swedish chemist Berg-
man, pursuing still further this subject of Chemical
Affinities, and the expression of them by means of
Tables, returned again to the old Newtonian term;
and designated the disposition of a body to combine.
with one rather than another of two others as Elective
Attraction. And as his work on Elective Attractions
had great circulation and great influence, this phrase
has obtained a footing by the side of Affinity, and both
one and the other are now in common use among
chemists.
4. I have said above that the term Affinity is
worthy of being retained as a technical term. If we
use the word attraction in this case, we identify or
compare chemical with mechanical attraction; from
which identification and comparison, as I have already
remarked, no one has yet been able to extract the means
of expressing any single scientific truth. If such an
identification or comparison be not intended, the use
of the same word in two different senses can only lead
to confusion; and the proper course, recommended by
all the best analogies of scientific history, is to adopt a
peculiar term for that peculiar relation on which che-
mical composition depends. The word Affinity, even if
it were not rigorously proper according to its common
meaning, still, being simple, familiar, and well esta-
blished in this very usage, is much to be preferred
before any other.
But further, there are some analogies drawn from
the common meaning of this word, which appear to
recommend it as suitable for the office which it has to
discharge. For common mechanical attractions and
+ Thomson's Chemistry, iii. 10.
Limbourg's Dissertation was pub-
lished at Liege, in 1761; and Le
Sage's at Geneva.
5 Dissertatio de Affinitate Corpo-
rum. Vindob. 1762.
6 Progr. I. II. de Affinitate Corpo-
rum Chimica. Jen. 1775, 1776.
C 2
20
PHILOSOPHY OF CHEMISTRY.
repulsions, the forces by which one body considered as
a whole acts upon another external to it, are, as we
have said, to be distinguished from those more inti-
mate ties by which the parts of each body are held to-
gether. Now this difference is implied, if we compare
the former relations, the attractions and repulsions, to
alliances and wars between States, and the latter, the
internal union of particles, to those bonds of affinity
which connect the citizens of the same state with one
another, and especially to the ties of Family. We have
seen that Boerhaave compares the union of two ele-
ments of a compound to their marriage; we must
allow,' says an eminent chemist of our own time”,
'that there is some truth in this poetical comparison.
It contains this truth, that the two become one to
most intents and purposes, and that the Unit thus
formed (the Family) is not a mere juxtaposition of the
component parts. And thus the Idea of Affinity as
the peculiar principle of chemical composition, is esta-
blished among chemists, and designated by a familiar
and appropriate name,
>
5. Analysis is possible.-We must, however, en-
deavour to obtain a further insight into this Idea, thus
fixed and named. We must endeavour to extricate, if
not from the Idea itself, from the processes by which it
has obtained acceptation and currency among chemists,
some principles which may define its application, some
additional specialities in the relations which it implies.
This we shall proceed to do.
The Idea of Affinity, as already explained, implies a
disposition to combine. But this combination is to be
understood as admitting also of a possibility of separa-
tion. Synthesis implies Analysis as conceivable: or to
recur to the image which we have already used, Di-
vorce is possible when the Marriage has taken place.
That there is this possibility, is a conviction implied
in all the researches of chemists, ever since the true
notion of composition began to predominate in their
investigations. One of the first persons who clearly
7 Dumas, Leçons de Phil. Chim. p. 363.
IDEA OF CHEMICAL AFFINITY.
2I
expressed this conviction was Mayow, an English phy-
sician, who published his Medico-Physical Tracts in
1674. The first of them De Sale-Nitro et Spiritu
Nitro-Aerio, contains a clear enunciation of this prin-
ciple. After showing how, in the combinations of
opposite elements, as acid and alkali, their properties
entirely disappear, and a new substance is formed not
at all resembling either of the ingredients, he adds³,
Although these salts thus mixed appear to be de-
stroyed it is still possible for them to be separated
from each other, with their powers still entire.' He
proceeds to exemplify this, and illustrates it by the
same image which I have already already alluded to:
'Salia acida a salibus volatilibus discedunt, ut cum
sale fixo tartari, tanquam sponso magis idoneo, conju-
gium strictius ineunt.' This idea of a synthesis which
left a complete analysis still possible, was opposed to a
notion previously current, that when two heterogene-
ous bodies united together and formed a third body,
the two constituents were entirely destroyed, and the
result formed out of their ruins'. And this concep-
tion of Synthesis and Analysis, as processes which
are possible successively and alternately, and each of
which supposes the possibility of the other, has been
the fundamental and regulative principle of the opera-
tions and speculations of analytical chemistry from the
time of Mayow to the present day.
6. Affinity is Elective.—When the idea of chemical
affinity, or disposition to unite, was brought into view
by the experiments and reasonings of chemists, they
found it necessary to consider this disposition as elec-
tive;-each element chose one rather than another of
the elements which were presented to it, and quitted
its union with one to unite with another which it pre-
ferred. This has already appeared in the passage just
quoted from Mayow. He adds in the same strain, ‘I
have no doubt that fixed salts choose one acid rather
than another, in order that they may coalesce with it

s Cap. xiv. p. 233.
Thomson's Chemistry, iii. 8.
22
PHILOSOPHY OF CHEMISTRY.
in a more intimate union.'-'Nullus dubito salia fixa
acidum unum præ aliis eligere, ut cum eodem arctiore
unione coalescant.' The same thought is expressed
and exemplified by other chemists: they notice in-
numerable cases in which, when an ingredient is com-
bined with a liquid, if a new substance be immersed
which has a greater affinity for the liquid, the liquid
combines with the new substance by election, and the
former ingedient is precipitated. Thus Stahl says",
In spirit of nitre dissolve silver; put in copper and
the silver is thrown down; put in iron and the copper
goes down; put in zinc, the iron precipitates; put in
volatile alkali, the zinc is separated; put in fixed al-
kali, the volatile quits its hold.'-As may be seen in
this example, we have in such cases, not only a prefer-
ence, but a long gradation of preferences. The spirit
of nitre will combine with silver, but it prefers copper;
prefers iron more; zine still more; volatile alkali yet
more; fixed alkali the most.
The same thing was proved to obtain with regard to
each element; and when this was ascertained, it be-
came the object of chemists to express these degrees of
preference, by lists in which substances were arranged
according to their disposition to unite with another
substance. In this manner was formed Geoffroy's Ta-
ble of Affinities (1718), which we have already men-
tioned. This Table was further improved by other
writers, as Gellert (1751) and Limbourg (1761). Fi-
nally Bergman improved these Tables still further,
taking into account not only the order of affinities of
each element for others, but the sum of the tendencies
to unite of each two elements, which sum, he held, de-
termined the resulting combination when several cle-
ments were in contact with each other.
7. As we have stated in the History", when the
doctrine of elective affinities had assumed this very
definite and systematic form, it was assailed by Ber-
thollet, who maintained, in his Essai de Statique

10 Zymotechnia, 1697, P. 117.
11 Hist. Ind. Sc. b. xiv. c. iii.
IDEA OF CHEMICAL AFFINITY.
23
Chimique, (1803,) that chemical affinities are not elec-
tive: that, when various elements are brought toge-
ther, their combinations do not depend upon the kind
of elements alone, but upon the quantity of each which
is present, that which is most abundant always enter-
ing most largely into the resulting compounds. It
may seem strange that it should be possible, at so late
a period of the science, to throw doubt upon a doctrine
which had presided over and directed its progress so
long. Proust answered Berthollet, and again main-
tained that chemical affinity is elective. I have, in
the History, given the judgment of Berzelius upon
this controversy. 'Berthollet,' he says, 'defended
(
himself with an acuteness which makes the reader
hesitate in his judgment; but the great mass of facts
finally decided the point in favour of Proust.' I may
here add the opinion pronounced upon this subject by
Dr. Turner: Bergman erred in supposing the re-
sult of the chemical action to be in every case owing
to elective affinity [for this power is modified in its
effects by various circumstances]: but Berthollet ran
into the opposite extreme in declaring that the effects
formerly ascribed to that power are never produced by
it. That chemical attraction is exerted between dif-
ferent bodies with different degrees of energy, is, I
apprehend, indisputable.' And he then proceeds to
give many instances of differences in affinity which
cannot be accounted for by the operation of any modi-
fying causes. Still more recently, M. Dumas has taken
a review of this controversy; and, speaking with en-
thusiasm of the work of Berthollet, as one which had
been of inestimable service to himself in his early study
of chemistry, he appears at first disposed to award to
him the victory in this dispute. But his final verdict
leaves undamaged the general principle now under our
consideration, that chemical affinity is elective. For
my own part,' he says¹³, 'I willingly admit the no-
tions of Berthollet when we have to do with acids or
12 Chemistry, p. 199. 6th edition.
13 Leçons de Philosophie Chimique, p. 386.
24
PHILOSOPHY OF CHEMISTRY.
with bases, of which the energy is nearly equal: but
when bodies endued with very energetic affinities are
in presence of other bodies of which the affinities are
very feeble, I propose to adopt the following rule: In
a solution, everything remaining dissolved, the strong
affinities satisfy themselves, leaving the weak affinities
to arrange matters with one another.
The strong
acids take the strong bases, and the weak acids can
only unite with the weak bases. The known facts are
perfectly in accordance with this practical rule.' It is
obvious that this recognition of a distinction between
strong and weak affinities, which operates to such an
extent as to determine entirely the result, is a complete
acknowledgement of the Elective nature of Affinity, as
far as any person acquainted with chemical operations
could contend for it. For it must be allowed by all,
that solubility, and other collateral circumstances, in-
fluence the course of chemical combinations, since they
determine whether or not there shall take place that
contact of elements without which affinity cannot pos-
sibly operate.
8. Affinity is Definite as to quantity.-In proportion
as chemists obtained a clearer view of the products of
the laboratory as results of the composition of elements,
they saw more and more clearly that these results were
definite; that one element not only preferred to com-
bine with another of a certain kind, but also would
combine with it to a certain extent and no further,
thus giving to the result not an accidental and vari-
able, but a fixed and constant character. Thus salts
being considered as the result of the combination of
two opposite principles, acid and alkali, and being
termed neutral when these principles exactly balanced
each other, Rouelle (who was Royal Professor at Paris
in 1742) admits of neutral salts with excess of acid,
neutral salts with excess of base, and perfect neutral
salts. Beaume maintained¹* against him that there
were no salts except those perfectly neutral, the other
classes being the results of mixture and imperfect com-
14 Dumas, Phil. Chim. p. 198.
IDEA OF CHEMICAL AFFINITY.
25
bination. But this question was not adequately treated
till chemists made every experiment with the balance
in their hands. When this was done, they soon dis-
covered that, in each neutral salt, the proportional
weights of the ingredients which composed it were
always the same. This was ascertained by Wenzel,
whose Doctrine of the Affinities of Bodies appeared in
1777. He not only ascertained that the proportions
of elements in neutral chemical compounds are defi-
nite, but also that they are reciprocal; that is, (to
express his results in a manner now employed by che-
mists), that if A, a certain weight of a certain acid,
neutralize m, a certain weight of a certain base, and B,
a certain weight of a certain other acid, neutralize n, a
certain weight of a certain other base; the compound
of a and n will also be neutral; as also that of B and m.
The same views were again presented by Richter in
1792, in his Principles of the Measure of Chemical
Elements. And along with these facts, that of the
combination of elements in multiple proportions being
also taken into account, the foundations of the Atomic
Theory were laid; and that Theory was propounded in
1803 by Mr. Dalton. That theory, however, rests
upon the Idea of Substance, as well as upon that Idea
of Chemical Affinity which we are here considering;
and the discussion of its evidence and truth must be
for the present deferred.
9. The two principles just explained, that Affinity
is Definite as to the Kind, and as to the Quantity of
the elements which it unites,--have here been stated as
results of experimental investigation. That they could
never have been clearly understood, and therefore
never firmly established, without laborious and exact
experiments, is certain; but yet we may venture to
say that being once fully known, they may seem to
thoughtful men to possess an evidence beyond that of
mere experiment. For how, in fact, can we conceive
combinations, otherwise than as definite in kind and
quantity? If we were to suppose each element ready
to combine with any other indifferently, and indif-
ferently in any quantity, we should have a world in
26
PHILOSOPHY OF CHEMISTRY.
which all would be confusion and indefiniteness.
There would be no fixed kinds of bodies. Salts, and
stones, and ores, would approach to and graduate
into each other by insensible degrees. Instead of
this, we know that the world consists of bodies dis-
tinguishable from each other by definite differences,
capable of being classified and named, and of having
general propositions asserted concerning them. And
as we cannot conceive a world in which this should
not be the case, it would appear that we cannot con-
ceive a state of things in which the laws of the com-
bination of elements should not be of that definite and
measured kind which we have above asserted.
This will, perhaps, appear more clearly by stating
our fundamental convictions respecting chemical com-
position in another form, which I shall, therefore, pro-
ceed to do.
10. Chemical Composition determines Physical Pro-
perties. However obscure and incomplete may be our
conception of the internal powers by which the ulti-
mate particles of bodies are held together, it involves,
at least, this conviction :-that these powers are what
determine bodies to be bodies, and therefore contain
the reason of all the properties which, as bodies, they
possess. The forces by which the particles of a body
are held together, also cause it to be hard or soft,
heavy or light, opake or transparent, black or red; for
if these forces are not the cause of these peculiarities,
what can be the cause? By the very supposition
which we make respecting these forces, they include
all the relations by which the parts are combined into
a whole, and therefore they, and they only, must deter-
mine all the attributes of the whole. The foundation
of all our speculations respecting the intimate constitu-
tion of bodies must be this principle, that their compo-
sition determines their properties.
Accordingly we find our chemists reasoning from
this principle with great confidence, even in doubtful
Thus Davy, in his researches concerning the
diamond, says: "That some chemical difference must
exist between the hardest and most beautiful of the
cases.
IDEA OF CHEMICAL AFFINITY.
27
gems and charcoal, between a non-conductor and a
conductor of electricity, it is scarcely possible to doubt:
and it seems reasonable to expect that a very refined or
perfect chemistry will confirm the analogies of nature;
and show that bodies cannot be the same in their
composition or chemical nature, and yet totally differ-
ent in their chemical properties.' It is obvious that
the principle here assumed is so far from being a mere
result of experience, that it is here appealed to to
prove that all previous results of experience on this
subject must be incomplete and inaccurate; and that
there must be some chemical difference between char-
coal and diamond, though none had hitherto been de-
tected.
II. In what manner, according to what rule, the
chemical composition shall determine the kind of the
substance, we cannot reasonably expect to determine by
mere conjecture or assumption, without a studious ex-
amination of natural bodies and artificial compounds.
Yet even in the most recent times, and among men of
science, we find that an assumption of the most arbi-
trary character has in one case been mixed up with
this indisputable principle, that the elementary compo-
sition determines the kind of the substance. In the
classification of minerals, one school of mineralogists
have rightly taken it as their fundamental principle
that the chemical composition shall decide the position
of the mineral in the system. But they have appended
to this principle, arbitrarily and unjustifiably, the
maxim that the element which is largest in quantity
shall fix the class of the substance. To make such an
assumption is to renounce, at once, all hope of framing
a system which shall be governed by the resemblances
of the things classified; for how can we possibly know
beforehand that fifty-five per cent. of iron shall give a
substance its predominant properties, and that forty-
five per cent. shall not? Accordingly, the systems of
mineralogical arrangement which have been attempted
in this way, (those of Haüy, Phillips, and others,) have
been found inconsistent with themselves, ambiguous,
and incapable of leading to any general truths.
28
PHILOSOPHY OF CHEMISTRY.
12. Chemical Composition and Crystalline Form cor-
respond.—Thus the physical properties of bodies de-
pend upon their chemical composition, but in a manner
which a general examination of bodies with reference
to their properties and their composition can alone
determine. We may, however, venture to assert
further, that the more definite the properties are, the
more distinct may we expect to find this dependence.
Now the most definite of the properties of bodies are
those constant properties which involve relations of
space; that is, their figure. We speak not, however,
of that external figure, derived from external circum-
stances, which, so far from being constant and definite,
is altogether casual and arbitrary; but of that figure
which arises from their internal texture, and which
shows itself not only in the regular forms which they
spontaneously assume, but in the disposition of the
parts to separate in definite directions, and no others.
In short, the most definite of the properties of perfect
chemical compounds is their crystalline structure; and
therefore it is evident that the crystalline structure
of each body, and the forms which it affects, must be
in a most intimate dependence upon its chemical com-
position.
Here again we are led to the brink of another
theory;—that of crystalline structure, which has ex-
cited great interest among philosophers ever since
the time of Haüy. But this theory involves, besides
that idea of chemical composition with which we are
here concerned, other conceptions, which enter into
the relations of figure. These conceptions, governed
principally by the Idea of Symmetry, must be unfolded
and examined before we can venture to discuss any
theory of crystallization: and we shall proceed to do
this as soon as we have first duly considered the Idea
of Substance and its consequences.
CHAPTER III.
OF THE IDEA OF SUBSTANCE.
1. Axiom of the Indestructibility of Substance.-WE
now come to an Idea of which the history is
very dif-
ferent from those of which we have lately been speak-
ing. Instead of being gradually and recently brought
into a clear light, as has been the case with the Ideas
of Polarity and Affinity, the Idea of Substance has
been entertained in a distinct form from the first periods
of European speculation. That this is so, is proved
by our finding a principle depending upon this Idea
current as an axiom among the early philosophers of
Greece:—namely, that nothing can be produced out of
nothing. Such an axiom, more fully stated, amounts
to this: that the substance of which a body consists is
incapable of being diminished (and consequently inca-
pable of being augmented) in quantity, whatever appa-
rent changes it may undergo. Its forms, its distribu-
tion, its qualities, may vary, but the substance itself is
identically the same under all these variations.
The axiom just spoken of was the great principle
of the physical philosophy of the Epicurean school, as
it must be of every merely material philosophy. The
reader of Lucretius will recollect the emphasis with
which it is repeatedly asserted in his poem:
E nilo nil gigni, in nilum nil posse reverti;
Nought comes of nought, nor ought returns to nought.
Those who engaged in these early attempts at phy-
sical speculation were naturally much pleased with the
clearness which was given to their notions of change,
composition, and decomposition, by keeping steadily
hold of the Idea of Substance, as marked by this
30
PHILOSOPHY OF CHEMISTRY.
fundamental axiom. Nor has its authority ever ceased
to be acknowledged. A philosopher was asked', What
is the weight of smoke? He answered, 'Subtract the
weight of the ashes from the weight of the wood which
is burnt, and you have the weight of the smoke.' This
reply would be assented to by all; and it assumes as
incontestable that even under the action of fire, the
material, the substance, does not perish, but only
changes its form.
This principle of the indestructibility of substance
might easily be traced in many reasonings and re-
searches, ancient and modern. For instance, when
the chemist works with the retort, he places the body
on which he operates in one part of an inclosed cavity,
which, by its bendings and communications, separates
at the same time that it confines, the products which
result from the action of fire: and he assumes that this
process is an analysis of the body into its ingredients,
not a creation of anything which did not exist before,
or a destruction of anything which previously existed.
And he assumes further, that the total quantity of the
substance thus analysed is the sum of the quantities
of its ingredients. This principle is the very basis of
chemical speculation, as we shall hereafter explain
more fully.
2. The Idea of Substance.-The axiom above spoken
of depends upon the Idea of Substance, which is in-
volved in all our views of external objects. We un-
avoidably assume that the qualities and properties
which we observe are properties of things;-that the
adjective implies a substantive;-that there is, besides
the external characters of things, something of which
they are the characters. An apple which is red, and
round, and hard, is not merely redness, and roundness,
and hardness: these circumstances may all alter while
the apple remains the same apple. Behind or under the
appearances which we see, we conceive something of
which we think; or, to use the metaphor which ob-
tained currency among the ancient philosophers, the
1 Kant, Kritik der R. V. p. 167.
H
IDEA OF SUBSTANCE.
3I
attributes and qualities which we observe are sup-
ported by and inherent in something: and this some-
thing is hence called a substratum or substance,—that
which stands beneath the apparent qualities and sup-
ports them.
That we have such an Idea, using the term 'Idea'
in the sense in which I have employed it throughout
these disquisitions, is evident from what has been
already said. The Axiom of the Indestructibility of
Substance proves the existence of the Idea of Sub-
stance, just as the Axioms of Geometry and Arith-
metic prove the existence of the Ideas of Space and
Number. In the case of Substance, as of space or
number, the ideas cannot be said to be borrowed from
experience, for the axioms have an authority of a far
more comprehensive and demonstrative character than
any which experience can bestow. The axiom that
nothing can be produced from nothing and nothing
destroyed, is so far from being a result of experience,
that it is apparently contradicted by the most obvious
observation. It has, at first, the air of a paradox; and
by those who refer to it, it is familiarly employed to
show how fallacious common observation is.
assertion is usually made in this form;-that nothing
is created and nothing annihilated, notwithstanding
that the common course of our experience appears to
show the contrary. The principle is not an empirical,
but a necessary and universal truth;—is collected, not
from the evidence of our senses, but from the operation
of our ideas. And thus the universal and undisputed
authority of the axiom proves the existence of the Idea
of Substance.
The
3. Locke's Denial of the Idea of Substance.—I shall
not attempt to review the various opinions which have
been promulgated respecting this Idea: but it may be
worth our while to notice briefly the part which it
played in the great controversy concerning the origin
of our ideas which Locke's Essay occasioned. Locke's
object was to disprove the existence of all ideas not
derived from Sensation or Reflection: and since the
idea of substance as distinct from external qualities, is
32
PHILOSOPHY OF CHEMISTRY.
manifestly not derived directly from sensation, nor by
any very obvious or distinct process from reflection,
Locke was disposed to exclude the idea as much as
possible. Accordingly, in his argumentation against
Innate Ideas², he says plainly, 'the idea of substance,
which we neither have nor can have by sensation or
reflection.' And the inference which he draws is,
'that we have no such clear idea at all.' What then,
it may be asked, do we mean by the word substance?
This also he answers, though somewhat strangely, 'We
signify nothing by the word substance, but only an un-
certain supposition of we know not what, i. e. of some-
thing whereof we have no particular distinct positive
idea, which we take to be the substratum, or support,
of those ideas we know.' That while he indulged in
this tautological assertion of our ignorance and uncer-
tainty, he should still have been compelled to acknow-
ledge that the word substance had some meaning, and
should have been driven to explain it by the identical
metaphors of 'substratum' and 'support,' is a curious
proof how impossible it is entirely to reject this idea.
But as we have already seen, the supposition of the
existence of substance is so far from being uncertain,
that it carries with it irresistible conviction, and sub-
stance is necessarily conceived as something which
cannot be produced or destroyed. It may be easily
supposed, therefore, that when the controversy between
Locke and his assailants came to this point, he would
be in some difficulty. And, indeed, though with his
accustomed skill in controversy, he managed to retain
a triumphant tone, he was driven from his main points.
Thus he repels the charge that he took the being of
substance to be doubtful. He says, 'Having every-
where affirmed and built upon it that man is a sub-
stance, I cannot be supposed to question or doubt of
the being of substance, till I can question or doubt of
my own being.' He attempts to make a stand by say-
ing that being of things does not depend upon our
2 Essay, b. i. c. iv. s. 18.
3 Essay, b. ii. c. ii. and First Letter to the Bishop of Worcester.
IDEA OF SUBSTANCE.
33
ideas; but if he had been asked how, without having
an idea of substance, he knew substance to be, it is
difficult to conceive what answer he could have made.
Again, he had said that our idea of substance arises
from our accustoming ourselves to suppose' a sub-
stratum of qualities. Upon this his adversary, Bishop
Stillingfleet, very properly asks, Is this custom ground-
ed upon true reason or no? To which Locke replies,
that it is grounded upon this: That we cannot con-
ceive how simple ideas of sensible qualities should sub-
sist alone; and therefore we suppose them to exist in,
and to be supported by some common subject, which
support we denote by the name substance. Thus he
allows, not only that we necessarily assume the reality
of substance, but that we cannot conceive qualities
without substance; which are concessions so ample as
almost to include all that any advocate for the Idea of
Substance need desire.
Perhaps Locke, and the adherents of Locke, in
denying that we have an idea of substance in general,
were latently influenced by finding that they could
not, by any effort of mind, call up any image which
could be considered as an image of substance in gene-
ral. That in this sense we have no idea of substance,
is plain enough; but in the same sense we have no
idea of space in general, or of time, or number, or
cause, or resemblance. Yet we certainly have such a
power of representing to our minds space, time, num-
ber, cause, resemblance, as to arrive at numerous
truths by means of such representations. These gene-
ral representations I have all along called Ideas, nor
can I discover any more appropriate word; and in this
sense, we have also, as has now been shown, an Idea
of Substance.
4. Is all Material Substance heavy ?-The princi-
ple that the quantity of the substance of any body
remains unchanged by our operations upon it, is, as
we have said, of universal validity. But then the
question occurs, how are we to ascertain the quantity
of substance, and thus, to apply the principle in parti-
cular cases. In the case above mentioned, where
VOL. II.
D
34
PHILOSOPHY OF CHEMISTRY.
smoke was to be weighed, it was manifestly assumed
that the quantity of the substance might be known by
its weight; and that the total quantity being un-
changed, the total weight also would remain the same.
Now on what grounds do we make this assumption?
Is all material substance heavy? and if we can assert
this to be so, on what grounds does the truth of the
assertion rest? These are not idle questions of barren
curiosity; for in the history of that science (Chemistry)
to which the Idea of Substance is principally applicable,
nothing less than the fate of a comprehensive and long
established theory (the Phlogiston theory) depended
upon the decision of this question. When it was urged
that the reduction of a metal from a calcined to a
metallic form could not consist in the addition of phlo-
giston, because the metal was lighter than the calx had
been; it was replied by some, that this was not con-
clusive, for that phlogiston was a principle of levity,
diminishing the weight of the body to which it was
added. This reply was, however, rejected by all the
sounder philosophers, and the force of the argument
finally acknowledged. But why was this suggestion of
a substance having no weight, or having absolute
levity, repudiated by the most reflective reasoners ?
It is assumed, it appears, that all matter must be
heavy; what is the ground of this assumption?
The ground of such an assumption appears to be
the following. Our idea of substance includes in it
this:—that substance is a quantity capable of addition ;
and thus capable of making up, by composition, a sum
equal to all its parts. But substance, and the quan-
tity of substance, can be known to us only by its attri-
butes and qualities. And the qualities which are
capable constantly and indefinitely of increase and
diminution by increase and diminution of the parts,
must be conceived inseparable from the substance.
For the qualities, if removable from the substance at
all, must be removable by some operation performed
upon the substance; and by the idea of substance, all
such operations are only equivalent to separation, junc-
tion, and union of parts. Hence those characters
IDEA OF SUBSTANCE.
35
which thus universally increase and diminish by addi-
tion and subtraction of the things themselves, belong
to the substance of the things. They are measures
of its quantity, and are not merely its separable qua-
lities.
The weight of bodies is such a character. However
we compound or divide bodies, we compound and
divide their weight in the same manner. We may dis-
member a body into the minutest parts; but the sum
of the weights of the parts is always equal to the
whole weight of the body. The weight of a body can
be in no way increased or diminished, except by add-
ing something to it or taking something from it. If
we bake a brick, we do not conceive that the change
of colour or of hardness, implies that anything has
been created or destroyed. It may easily be that the
parts have only assumed a new arrangement; but if
the brick have lost weight, we suppose that something
(moisture for instance) has been removed elsewhere.
Thus weight is apprehended as essential to matter.
In considering the dismemberment or analysis of
bodies, we assume that there must be some criterion
of the quantity of substance; and this criterion can
possess no other properties than their weight possesses.
If we assume an element which has no weight, or the
weight of which is negative, as some of the defenders
of phlogiston attempted to do, we put an end to all
speculation on such subjects. For if weight is not
the criterion of the quantity of one element, phlogiston
for instance, why is weight the criterion of the quantity
of any other element? We may, by the same right,
assume any other real or imaginary element to have
levity instead of gravity; or to have a peculiar inten-
sity of gravity which makes its weight no index of its
quantity. In short, if we do this, we deprive of all
possibility of application our notions of element, analy-
sis, and composition; and violate the postulates on
which the questions are propounded which we thus
attempt to decide.
We must, then, take a constant and quantitative
property of matter, such as weight is, to be an index
D 2
36
PHILOSOPHY OF CHEMISTRY.
of the quantity of matter or of substance to which it
belongs. I do not here speak of the question which
has sometimes been proposed, whether the weight or
the inertia of bodies be the more proper measure of
the quantity of matter. For the measure of inertia is
regulated by the same assumption as that of sub-
stance:—that the quantity of the whole must be equal
to the quantity of all the parts: and inertia is mea-
sured by weight, for the same reason that substance
is so.
Having thus established the certainty, and ascer-
tained the interpretation of the fundamental principle
which the Idea of Substance involves, we are prepared
to consider its application in the science upon which it
has a peculiar bearing.
NOTE TO CHAPTER III.
[3rd Ed.]-[THE doctrine here propounded, that All
Matter is Heavy, has been opposed by Sir William
Hamilton of Edinburgh. (Works of Reid, note, p. 853.)
This writer is a man of unquestionable acuteness and
of very extensive reading; but his acuteness shows
itself in barren ontological distinctions, which appear
to me to be of the same character as the speculations
of the eminent Schoolmen of the most sterile periods of
the dark ages. That he should have no conception of
progressive or inductive science is not wonderful, when
we recollect that he holds, as an important part of his
philosophy, that the study of mathematics perverts and
obscures the mind. But it may be of some interest to
consider his objections to the doctrine here maintained.
He says,, Ist, that our reasoning assumes that we
must necessarily have it in our power to ascertain the
Quantity of Matter; whereas this may be a problem
out of the reach of human determination.
To this I reply, that my reasoning does assume that
there is a science, or sciences, which make assertions
concerning the Quantity of Matter: Mechanics and
Chemistry are such sciences. My assertion is, that to
make such sciences possible, Quantity of Matter must
be proportional to Weight. If my opponent deny that
Mechanics and Chemistry can exist as sciences, he may
invalidate my proof; but not otherwise.
2. He says that there are two conceivable ways of
estimating the Quantity of Matter: by the Space occu-
pied, and by the Weight or Inertia; and that I assume
the second measure gratuitously.
To which I reply, that the most elementary steps in
Mechanics and in Chemistry contradict the notion that
38
PHILOSOPHY OF CHEMISTRY.
the Quantity of Matter is proportionate to the Space.
They proceed necessarily on a distinction between
Space and Matter:-between mere Extension and ma-
terial Substance.
3. He allows that we cannot make the Extension of
a body the measure of the Quantity of Matter, because,
he says, we do not know if 'the compressing force' is
such as to produce the closest compression.' That is,
he assumes a compressing force, assumes a closest com-
pression, assumes a peculiar (and very improbable)
atomic hypothesis; and all this to supply a reason why
we are not to believe the first simple principle of
Mechanics and Chemistry.
4. He speaks of a series of apparent fluids (as Light
or its vehicle, the Calorific, the Electro-galvanic, and
Magnetic agents) which we can neither denude of their
character of substance, nor clothe with the attribute of
weight.'
To which my reply is, that precisely because I cannot
'clothe' these agents with the attribute of Weight, I
do denude them of the character of Substance.' They
are not substances, but agencies. These Imponderable
Agents are not properly called 'Imponderable Fluids.'
This I conceive that I have proved; and the proof is
not shaken by denying the conclusion without showing
any defect in the reasoning.
5. Finally, my critic speaks about 'a logical canon,'
and about 'a criterion of truth, subjectively necessary
and objectively certain;' which matters I shall not
waste the reader's time by discussing.]
CHAPTER IV.
APPLICATION OF THE IDEA OF SUBSTANCE IN
CHEMISTRY.
I. A Body is Equal to the Sum of its Elements.—
FROM the earliest periods of chemistry the balance has
been familiarly used to determine the proportions of
the ingredients and of the compound; and soon after
the middle of the last century, this practice was so
studiously followed, that Wenzel and Richter were
thereby led to the doctrine of Definite Proportions.
But yet the full value and significance of the balance,
as an indispensable instrument in chemical researches,
was not understood till the gaseous, as well as solid
and fluid ingredients were taken into the account.
When this was done, it was found that the principle,
that the whole is equal to the sum of its parts, of
which, as we have seen, the necessary truth, in such
cases, flows from the idea of substance, could be applied
in the most rigorous manner. And conversely, it was
found that by the use of the balance, the chemist
could decide, in doubtful cases, which was a whole, and
which were parts.
For chemistry considers all the changes which belong
to her province as compositions and decompositions of
elements; but still the question may occur, whether an
observed change be the one or the other. How can we
distinguish whether the process which we contemplate
be composition or decomposition?-whether the new
body be formed by addition of a new, or subtraction of
an old element? Again; in the case of decomposition,
we may inquire, What are the ultimate limits of our
analysis? If we decompound bodies into others more
and more simple, how far can we carry this succession
40
PHILOSOPHY OF CHEMISTRY.
of processes? How far can we proceed in the road of
analysis? And in our actual course, what evidence
have we that our progress, as far as it has gone, has
carried us from the more complex to the more simple?
To this we reply, that the criterion which enables
us to distinguish, decidedly and finally, whether our
process have been a mere analysis of the proposed body
into its ingredients, or a synthesis of some of them with
some new element, is the principle stated above, that
the weight of the whole is equal to the weight of
all the parts. And no process of chemical analysis or
synthesis can be considered complete till it has been
verified by this fact;--by finding that the weight of the
compound is the weight of its supposed ingredients; or,
that if there be an element which we think we have
detached from the whole, its loss is betrayed by a cor-
responding diminution of weight.
Í have already noticed what an important part this
principle has played in the great chemical controversy
which ended in the establishment of the oxygen theory.
The calcination of a metal was decided to be the union
of oxygen with the metal, and not the separation of
phlogiston from it, because it was found that in the
pro-
cess of calcination, the weight of the metal increased,
and increased exactly as much as the weight of ambient
air diminished. When oxygen and hydrogen were ex-
ploded together, and a small quantity of water was
produced, it was held that this was really a synthesis
of water, because, when very great care was taken
with the process, the weight of the water which resulted
was equal to the weight of the gases which disappeared.
2. Lavoisier. It was when gases came to be con-
sidered as entering largely into the composition of
liquid and solid bodies, that extreme accuracy in weigh-
ing was seen to be so necessary to the true under-
standing of chemical processes. It was in this manner
discovered by Lavoisier and his contemporaries that
oxygen constitutes a large ingredient of calcined metals,
of acids, and of water. A countryman of Lavoisier¹
?
1 M. Dumas, Leçons de la Philosophie Chimique. 1837. P. 157.
APPLICATION OF THE IDEA OF SUBSTANCE. 41
has not only given most just praise to that great phi-
losopher for having constantly tested all his processes
by a careful and skilful use of the balance, but has also
claimed for him the merit of having introduced the
maxim, that in chemical operations nothing is created
and nothing lost. But I think it is impossible to
deny that this maxim is assumed in all the attempts at
analysis made by his contemporaries, as well as by him.
This maxim is indeed included in any clear notion of
analysis: it could not be the result of the researches of
any one chemist, but was the governing principle of
the reasonings of all. Lavoisier, however, employed
this principle with peculiar assiduity and skill. In
applying it, he does not confine himself to mere addi-
tions and subtractions of the quantities of ingredients;
but often obtains his results by more complex pro-
cesses. In one of his investigations he says, 'I may
consider the ingredients which are brought together,
and the result which is obtained as an algebraical equa-
tion; and if I successively suppose each of the quanti-
ties of this equation to be unknown, I can obtain its
value from the rest: and thus I can rectify the experi-
ment by the calculation, and the calculation by the ex-
periment. I have often taken advantage of this
method, in order to correct the first results of my ex-
periments, and to direct me in repeating them with
proper precautions.'
The maxim, that the whole is equal to the sum of
all its parts, is thus capable of most important and
varied employment in chemistry. But it may be ap-
plied in another form to the exclusion of a class of
speculations which are often put forwards.
Maxim respecting Imponderable Elements.-
Several of the phenomena which belong to bodies, as
heat, light, electricity, magnetism, have been explained
hypothetically by assuming the existence of certain
fluids; but these fluids have never been shown to have
weight. Hence such hypothetical fluids have been
termed imponderable elements. It is however plain,
that so long as these fluids appear to be without
weight, they are not elements of bodies in the same
42
PHILOSOPHY OF CHEMISTRY.
sense as those elements of which we have hitherto
been speaking. Indeed we may with good reason
doubt whether those phenomena depend upon trans-
ferable fluids at all. We have seen strong reason to
believe that light is not matter, but only motion; and
the same thing appears to be probable with regard to
heat. Nor is it at all inconceivable that a similar
hypothesis respecting electricity and magnetism should
hereafter be found tenable. Now if heat, light, and
those other agents, be not matter, they are not ele-
ments in such a sense as to be included in the prin-
ciple referred to above, That the body is equal to the
sum of its elements. Consequently the maxim just
stated, that in chemical operations nothing is created,
nothing annihilated, does not apply to Light and Heat.
They are not things. And whether heat can be pro-
duced where there was no heat before, and light struck
out from darkness, the ideas of which we are at pre-
sent treating do not enable us to say.
In reasoning
respecting chemical synthesis and analysis therefore,
we shall only make confusion by attempting to include
in our conception the Light and Heat which are pro-
duced and destroyed. Such phenomena may be very
proper subjects of study, as indeed they undoubtedly
are; but they cannot be studied to advantage by con-
sidering them as sharing the nature of composition
and decomposition.
Again: in all attempts to explain the processes of
nature, the proper course is, first to measure the facts
with precision, and then to endeavour to understand
their cause.
Now the facts of chemical composition
and decomposition, the weights of the ingredients and
of the compounds, are facts measurable with the ut-
most precision and certainty. But it is far otherwise
with the light and heat which accompany chemical
processes. When combustion, deflagration, explosion,
takes place, how can we measure the light or the heat?
Even in cases of more tranquil action, though we can
apply the thermometer, what does the thermometer
tell us respecting the quantity of the heat? Since
then we have no measure which is of any value as
APPLICATION OF THE IDEA OF SUBSTANCE. 43
regards such circumstances in chemical changes, if we
attempt to account for these phenomena on chemical
principles, we introduce, into investigations in them-
selves perfectly precise and mathematically rigorous,
another class of reasonings, vague and insecure, of
which the only possible effect is to vitiate the whole
reasoning, and to make our conclusions inevitably
erroneous.
We are led then to this maxim: that imponderable
fluids are not to be admitted as chemical elements of
bodies².
4. It appears, I think, that our best and most philo-
sophical chemists have proceeded upon this principle
in their investigations. In reasoning concerning the
constitution of bodies and the interpretation of che-
mical changes, the attempts to include in these inter-
pretations the heat or cold produced, by the addition
or subtraction of a certain hypothetical caloric,' have
become more and more rare among men of science.
Such statements, and the explanations often put for-
wards of the light and heat which appear under various
circumstances in the form of fire, must be considered
as unessential parts of any sound theory. Accordingly
we find Mr. Faraday gradually relinquishing such
views. In January, 1834, he speaks generally of an
hypothesis of this kind³: 'I cannot refrain from
recalling here the beautiful idea put forth, I believe
by Berzelius, in his development of his views of the
electro-chemical theory of affinity, that the heat and
light evolved during cases of powerful combination
2 See the answer to Sir William
Hamilton's objections, at the end of
the last chapter.
pressure to have any effect upon
such elements. To make this suppo-
sition, is to connect the most subtle
and incorporeal objects which we
know in nature by the most gross
material ties. This remark seems to
be applicable to M. Poisson's hypo-
thesis that the electric fluid is re-
tained at the surface of bodies by the
pressure of the atmosphere.
3 Researches, 870.
Since we are thus warned by a
sound view of the nature of science,
from considering chemical affinity
as having any hold upon imponder-
able elements, we are manifestly
still more decisively prohibited from
supposing mechanical impulse or
44
PHILOSOPHY OF CHEMISTRY.
:
are the consequence of the electric discharge which is
at that moment taking place.' But in April of the
same year*, he observes, that in the combination of
oxygen and hydrogen to produce water, electric powers
to a most enormous amount are for the time active,
but that the flame which is produced gives but feeble
traces of such powers. 'Such phenomena,' therefore,
he adds, 'may not, cannot, be taken as evidences of the
nature of the action; but are merely incidental results,
incomparably small in relation to the forces concerned,
and supplying no information of the way in which
the particles are active on each other, or in which
their forces are finally arranged.'
In pursuance of this maxim, we must consider as
an unessential part of the oxygen theory that portion
of it, much insisted upon by its author at the time,
in which when sulphur, for instance, combined with
oxygen to produce sulphuric acid, the combustion was
accounted for by means of the caloric which was
supposed to be liberated from its combination with
oxygen.
5. Controversy of the Composition of Water.-There
is another controversy of our times to which we may
with great propriety apply the maxim now before us.
After the glory of having first given a true view of
the composition of water had long rested tranquilly
upon the names of Cavendish and Lavoisier, a claim
was made in favour of James Watt as the real author
of this discovery by his son, (Mr J. Watt,) and his
eulogist, (M. Arago). It is not to our purpose here
to discuss the various questions which have arisen on
this subject respecting priority of publication, and
respecting the translation of opinions published at one
time into the language of another period. But if we
look at Watt's own statement of his views, given soon
after those of Cavendish had been published, we shall
perceive that it is marked by a violation of this maxim :
we shall find that he does admit imponderable fluids
4 Researches, 960.
5 Éloge de James Watt, Annuaire du Bur. des Long. 1839.
APPLICATION OF THE IDEA OF SUBSTANCE. 45
as chemical elements; and thus shows a vagueness and
confusion in his idea of chemical composition. With
such imperfection in his views, it is not surprising
that Watt, not only did not anticipate, but did not
apprehend quite precisely the discovery of Cavendish
and Lavoisier. Watt's statement of his views is as
follows:-"Are we not authorized to conclude that
water is composed of dephlogisticated air and phlogis-
ton deprived of part of their latent or elementary
heat; that dephlogisticated or pure air is composed of
water deprived of its phlogiston and united to ele-
mentary heat and light; and that the latter are con-
tained in it in a latent state, so as not to be sensible
to the thermometer or to the eye; and if light be only
a modification of heat, or a circumstance attending it,
or a component part of the inflammable air, then pure
or dephlogisticated air is composed of water deprived
of its phlogiston and united to elementary heat?"
When we compare this doubtful and hypothetical
statement, involving so much that is extraneous and
heterogeneous, with the conclusion of Cavendish, in
which there is nothing hypothetical or superfluous, we
may confidently assent to the decision which has been
pronounced by one' of our own time in favour of
Cavendish. And we may with pleasure recognize, in
this enlightened umpire, a due appreciation of the
value of the maxim on which we are now insisting.
'Cavendish,' says Mr. Vernon Harcourt, 'pared off
6 Phil. Trans. 1784, P. 332.
7 The Rev. W. Vernon Harcourt,
Address to the British Association,
1839-Since the first edition of this
work was published, and also since
the second edition of the History of
the Inductive Sciences, Mr. Watt's
correspondence bearing upon the
question of the Composition of Water
has been published by Mr. Muirhead
I do not find, in this publication, any
reason for withdrawing what I have
stated in the text above: but with
reference to the statement in the
History, it appears that Mr. Caven-
dish's claim to the discovery was not
uncontested in his own time. Mr.
Watt had looked at the composition
of water, as a problem to be solved,
perhaps more distinctly than Mr. Ca-
vendish had done; and he conceived
himself wronged by Mr. Cavendish's
putting forwards his experiment as
the first solution of this problem.
46
PHILOSOPHY OF CHEMISTRY.
from the hypotheses their theories of combustion, and
affinities of imponderable for ponderable matter, as
complicating chemical with physical considerations.'
•
6. Relation of Heat to Chemistry.-But while we
thus condemn the attempts to explain the thermotical
phenomena of chemical processes by means of chemical
considerations, it may be asked if we are altogether
to renounce the hope of understanding such pheno-
mena? It is plain, it may be said, that heat generated
in chemical changes is always a very important cir-
cumstance, and can sometimes be measured, and per-
haps reduced to laws; are we prohibited from specu-
lating concerning the causes of such circumstances
and such laws? And to this we reply, that we may
properly attempt to connect chemical with thermotical
processes, so far as we have obtained a clear and
probable view of the nature of the thermotical pro-
cesses. When our theory of Thermotics is tolerably
complete and certain, we may with propriety under-
take to connect it with our theory of Chemistry. But
at present we are not far enough advanced in our
knowledge of heat to make this attempt with any
hope of success. We can hardly expect to understand
the part which heat plays in the union of two bodies,
when we cannot as yet comprehend in what manner it
produces the liquefaction or vaporization of one body.
We cannot look to account for Gay Lussac and Dalton's
Law, that all gases expand equally by heat, till we
learn how heat causes a gas to expand. We cannot
hope to see the grounds of Dulong and Petit's Law,
that the specific heat of all atoms is the same, till we
know much more, not only about atoms, but about
specific heat. We have as yet no thermotical theory
which even professes to account for all the prominent
facts of the subject: and the theories which have
been proposed are of the most diverse kind. Laplace
assumes particles of bodies surrounded by atmospheres
of caloric⁹; Cauchy makes heat consist in longitudinal
vibrations of the ether of which transverse vibrations
8 Hist. Ind. Sci. b. x. c. 4
9 Ib.
APPLICATION OF THE IDEA OF SUBSTANCE. 47
produce light: in Ampère's theory, heat consists in
the vibrations of the particles of bodies. And so long
as we have nothing more certain in our conceptions of
heat than the alternative of these and other precarious
hypotheses, how can we expect to arrive at any real
knowledge, by connecting the results of such hypothe-
ses with the speculations of Chemistry, of which science
the theory is at least equally obscure?
The largest attempts at chemical theory have been
made in the form of the Atomic Theory, to which I
have just had occasion to allude. I must, therefore,
before quitting the subject, say a few words respecting
this theory.
10 Hist. Ind. Sci. b. x. c. 4.
1
CHAPTER V.
THE ATOMIC THEORY.
I. The Atomic Theory considered on Chemical
Grounds. We have already seen that the combina-
tions which result from chemical affinity are definite, a
certain quantity of one ingredient uniting, not with
an uncertain, but with a certain quantity of another
ingredient. But it was found, in addition to this prin-
ciple, that one ingredient would often unite with
another in different proportions, and that, in such
cases, these proportions are multiples one of another.
In the three salts formed by potassa with oxalic acid,
the quantities of acid which combine with the same
quantity of alkali are exactly in the proportion of the
numbers 1, 2, 4.
And the same rule of the exist-
ence of multiple proportions is found to obtain in other
cases.
It is obvious that such results will be accounted for,
if we suppose that the base and the acid consist each of
numerous definite equal particles, and that the forma-
tion of the salts above mentioned consists in the combi-
nation of one particle of the base with one particle of
acid, with two particles of acid, and with four particles.
of acid, respectively. But further; as we have already
stated, chemical affinity is not only definite, but recipro-
cal. The proportions of potassa and soda which form
neutral salts being 590 and 391 in one case, they are so
in all cases. These numbers represent the proportions of
weight in which the two bases, potassa and soda, enter
into analogous combinations; 590 of potassa is equiva-
lent to 391 of soda. These facts with regard to com-
bination are still expressed by the above supposition
of equal particles, assuming that the weights of a
THE ATOMIC THEORY.
49
particle of potassa and of soda are in the proportion
of 590 to 391.
But we pursue our analysis further. We find that
potassa is a compound of a metallic base, potassium,
and of oxygen, in the proportion of 490 to 100; we
suppose, then, that the particle of potassa consists of
a particle of potassium and a particle of oxygen; and
these latter particles, since we see no present need to
suppose them divided, potassium and oxygen being
simple bodies, we may call atoms, and assume to be
indivisible. And by supposing all simple bodies to
consist of such atoms, and compounds to be formed by
the union of two, or three, or more of such atoms, we
explain the occurrence of definite and multiple propor-
tions, and we construct the Atomic Theory.
2. Hypothesis of Atoms.-So far as the assumption
of such atoms as we have spoken of serves to express
those laws of chemical composition which we have
referred to, it is a clear and useful generalization. But
if the Atomic Theory be put forwards (and its author,
Dr. Dalton, appears to have put it forwards with such
an intention,) as asserting that chemical elements are
really composed of atoms, that is, of such particles not
further divisible, we cannot avoid remarking, that for
such a conclusion, chemical research has not afforded,
nor can afford, any satisfactory evidence whatever.
The smallest observable quantities of ingredients, as
well as the largest, combine according to the laws of
proportions and equivalence which have been cited
above. How are we to deduce from such facts any
inference with regard to the existence of certain small-
est possible particles? The Theory, when dogmati-
cally taught as a physical truth, asserts that all ob-
servable quantities of elements are composed of pro-
portional numbers of particles which can no further
be subdivided; but all which observation teaches us is,
that if there be such particles, they are smaller than
the smallest observable quantities. In chemical ex-
periment, at least, there is not the slightest positive
evidence for the existence of such atoms. The assump-
tion of indivisible particles, smaller than the smallest
VOL. II.
E
50
PHILOSOPHY OF CHEMISTRY.
observable, which combine, particle with particle, will
explain the phenomena; but the assumption of parti-
cles bearing this proportion, but not possessing the
property of indivisibility, will explain the phenomena
at least equally well. The decision of the question,
therefore, whether the Atomic Hypothesis be the pro-
per way of conceiving the chemical combinations of
substances, must depend, not upon chemical facts, but
upon our conception of Substance. In this sense the
question is an ancient and curious controversy, and
we shall hereafter have to make some remarks upon it.
3. Chemical Difficulties of the Hypothesis.-But
before doing this, we may observe that there is no
small difficulty in reconciling this hypothesis with the
facts of chemistry. According to the theory, all salts,
compounded of an acid and a base, are analogous in
their atomic constitution; and the number of atoms in
one such compound being known or assumed, the
number of atoms in other salts may be determined.
But when we proceed in this course of reasoning to
other bodies, as metals, we find ourselves involved in
difficulties. The protoxide of iron is a base which,
according to all analogy, must consist of one atom of
iron and one of oxygen: but the peroxide of iron is
also a base, and it appears by the analysis of this sub-
stance that it must consist of two-thirds of an atom of
iron and one atom of oxygen. Here, then, our indi-
visible atoms must be divisible, even upon chemical
grounds. And if we attempt to evade this difficulty
by making the peroxide of iron consist of two atoms of
iron and three of oxygen, we have to make a corre-
sponding alteration in the theoretical constitution of
all bodies analogous to the protoxide; and thus we
overturn the very foundation of the theory. Chemical
facts, therefore, not only do not prove the Atomic
Theory as a physical truth, but they are not, according
to any modification yet devised of the theory, recon-
cileable with its scheme.
Nearly the same conclusions result from the at-
tempts to employ the Atomic Hypothesis in express-
ing another important chemical law;-the law of the
THE ATOMIC THEORY.
5I
combinations of gases according to definite proportions
of their volumes, experimentally established by Gay
Lussac¹. In order to account for this law, it has been
very plausibly suggested that all gases, under the same
pressure, contain an equal number of atoms in the
same space; and that when they combine, they unite
atom to atom. Thus one volume of chlorine unites
with one volume of hydrogen, and forms hydrochloric
acid. But then this hydrochloric acid occupies the
space of the two volumes; and therefore the proper
number of particles cannot be supplied, and the uni-
form distribution of atoms in all gases maintained,
without dividing into two each of the compound parti-
cles, constituted of an atom of chlorine and an atom of
hydrogen. And thus in this case, also, the Atomic
Theory becomes untenable if it be understood to imply
the indivisibility of the atoms.
3
In all these attempts to obtain a distinct physical
conception of chemical union by the aid of the Atomic
Hypothesis, the atoms are conceived to be associated by
certain forces of the nature of mechanical attractions.
But we have already seen that no such mode of con-
ception can at all explain or express the facts of che-
mical combination; and therefore it is not wonderful
that when the Atomic Theory attempts to give an
account of chemical relations by contemplating them
under such an aspect, the facts on which it grounds
itself should be found not to authorize its positive doc-
trines; and that when these doctrines are tried upon
the general range of chemical observation, they should
prove incapable of even expressing, without self-con-
tradiction, the laws of phenomena.
4. Grounds of the Atomic Doctrine.-Yet the doc-
trine of atoms, or of substance as composed of indivisi-
ble particles, has in all ages had great hold upon the
minds of physical speculators; nor would this doc-
trine ever have suggested itself so readily, or have
been maintained so tenaciously, as the true mode of
1 Hist. Ind. Sc. b. xiv. c. 8.
2 Dumas, Phil. Chim. 263.
3 See Chapter I. of this book.
E 2
52
PHILOSOPHY OF CHEMISTRY.
conceiving chemical combinations, if it had not been
already familiar to the minds of those who endeavour
to obtain a general view of the constitution of nature.
The grounds of the assumption of the atomic structure
of substance are to be found rather in the idea of
substance itself, than in the experimental laws of che-
mical affinity. And the question of the existence of
atoms, thus depending upon an idea which has been
the subject of contemplation from the very infancy of
philosophy, has been discussed in all ages with interest
and ingenuity. On this very account it is unlikely that
the question, so far as it bears upon chemistry, should
admit of any clear and final solution. Still it will be
instructive to look back at some of the opinions which
have been delivered respecting this doctrine.
5. Ancient Prevalence of the Atomic Doctrine.—The
doctrine that matter consists of minute, simple, indi-
visible, indestructible particles as its ultimate elements,
has been current in all ages and countries, whenever
the tendency of man to wide and subtle speculations
has been active. I need not attempt to trace the his-
tory of this opinion in the schools of Greece and Italy.
It was the leading feature in the physical tenets of
the Epicureans, and was adopted by their Roman dis-
ciples, as the poem of Lucretius copiously shows us.
The same tenet had been held at still earlier periods,
in forms more or less definite, by other philosophers.
It is ascribed to Democritus, and is said to have been by
him derived from Leucippus. But this doctrine is found
also, we are told, among the speculations of another
intellectual and acute race, the Hindoos. According
to some of their philosophical writers, the ultimate
elements of matter are atoms, of which it is proved by
certain reasonings, that they are each one-sixth of one
of the motes that float in the sunbeam.
This early prevalence of controversies of the widest
and deepest kind, which even in our day remain unde-
cided, has in it nothing which need surprize us; or, at
least, it has in it nothing which is not in conformity
* By Mr. Colebrook. Asiatic Res. 1824.
THE ATOMIC THEORY.
53
with the general course of the history of philosophy.
As soon as any ideas are clearly possessed by the
human mind, its activity and acuteness in reasoning
upon them are such, that the fundamental antitheses
and ultimate difficulties which belong to them are soon
brought into view. The Greek and Indian philoso-
phers had mastered completely the Idea of Space, and
possessed the Idea of Substance in tolerable distinct-
ness. They were, therefore, quite ready, with their
lively and subtle minds, to discuss the question of the
finite and infinite divisibility of matter, so far as it in-
volved only the ideas of space and of substance, and
this accordingly they did with great ingenuity and per-
severance.
But the ideas of Space and of Substance are far from
being sufficient to enable men to form a complete gene-
ral view of the constitution of matter. We must add
to these ideas, that of mechanical Force with its anta-
gonist Resistance, and that of the Affinity of one kind
of matter for another. Now the former of these ideas
the ancients possessed in a very obscure and confused
manner; and of the latter they had no apprehension
whatever. They made vague assumptions respecting
the impact and pressure of atoms on each other; but
of their mutual attraction and repulsion they never
had any conception, except of the most dim and
wavering kind; and of an affinity different from mere
local union they did not even dream. Their specula-
tions concerning atoms, therefore, can have no value
for us, except as a part of the history of science. If
their doctrines appear to us to approach near to the
conclusions of our modern philosophy, it must be be-
cause our modern philosophy is that philosophy which
has not fully profited by the additional light which
the experiments and meditations of later times have
thrown upon the constitution of matter.
6. Bacon. Still, when modern philosophers look
upon the Atomic Theory of the ancients in a general
point of view merely, without considering the special
conditions which such a theory must fulfil, in order to
represent the discoveries of modern times, they are
54
PHILOSOPHY OF CHEMISTRY.
disposed to regard it with admiration. Accordingly
we find Francis Bacon strongly expressing such a feel-
ing. The Atomic Theory is selected and dwelt upon
by him as the chain which connects the best parts of
the physical philosophy of the ancient and the modern
world. Among his works is a remarkable dissertation
On the Philosophy of Democritus, Parmenides, and
Telesius: the last mentioned of whom was one of the
revivers of physical science in modern times. In this
work he speaks of the atomic doctrine of Democritus
as a favourable example of the exertions of the undis-
ciplined intellect. Hæc ipsa placita, quamvis paulo
emendatiora, talia sunt qualia esse possunt illa quæ ab
intellectu sibi permisso, nec continenter et gradatim
sublevato, profecta videntur.' These doctrines, thus
[in an ancient fable] presented in a better form, are
such glimpses of truth as can be obtained by the in-
tellect left to its own natural impulses, and not
ascending by successive and connected steps,' [as the
Baconian philosophy directs]. Accordingly,' he adds,
'the doctrine of Atoms, from its going a step beyond
the period in which it was advanced, was ridiculed by
the vulgar, and severely handled in the disputations of
the learned, notwithstanding the profound acquaint-
ance with physical science by which its author was
allowed to be distinguished, and from which he ac-
quired the character of a magician.'
(
C
'However,' he continues, neither the hostility of
Aristotle, with all his skill and vigour in disputation,
(though, like the Ottoman sultans, he. laboured to
destroy all his brother philosophers that he might rest
undisputed master of the throne of science,) nor the
majestic and lofty authority of Plato, could effect the
subversion of the doctrine of Democritus. And while
the opinions of Plato and Aristotle were rehearsed
with loud declamation and professorial pomp in the
schools, this of Democritus was always held in high
honour by those of a deeper wisdom, who followed in
silence a severer path of contemplation. In the days
of Roman speculation it kept its ground and its favour ;
Cicero everywhere speaks of its author with the great-
THE ATOMIC THEORY.
55
est praise; and Juvenal, who, like poets in general,
probably expressed the prevailing judgment of his
time, proclaims his merit as a noble exception to the
general stupidity of his countrymen.
Cujus prudentia monstrat
Magnos posse viros et magna exempla daturos
Vervecum in patriâ crassoque sub aere nasci.
'The destruction of this philosophy was not effected
by Aristotle and Plato, but by Genseric and Attila,
and their barbarians. For then, when human know-
ledge had suffered shipwreck, those fragments of the
Aristotelian and Platonic philosophy floated on the
surface like things of some lighter and emptier sort,
and so were preserved; while more solid matters went
to the bottom, and were almost lost in oblivion.'
7. Modern Prevalence of the Atomic Doctrine.—It
is our business here to consider the doctrine of Atoms
only in its bearing upon existing physical sciences,
and I must therefore abstain from tracing the various
manifestations of it in the schemes of hypothetical
cosmologists;—its place among the vortices of Descartes,
its exhibition in the monads of Leibnitz. I will, how-
ever, quote a passage from Newton to show the hold
it had upon his mind.
At the close of his Opticks he says, 'All these things.
being considered, it seems probable to me that God,
in the beginning, formed matter in solid, massy, hard,
impenetrable, moveable particles, of such sizes and
figures, and with such other properties, and in such
proportions to space, as most conduced to the end for
which He formed them; and that the primitive parti-
cles, being solids, are incomparably harder than any
porous bodies compounded of them, even so very hard
as never to wear or break in pieces; no ordinary power
being able to divide what God had made one in the
first creation. While the particles continue entire,
they may compose bodies of one and the same nature
and texture in all ages: but should they wear away or
break in pieces, the nature of things depending on
them would be changed. Water and earth composed
56
PHILOSOPHY OF CHEMISTRY.
of old worn particles and fragments of particles would
not be of the same nature and texture now with water
and earth composed of entire particles in the begin-
ning. And therefore that nature may be lasting, the
changes of corporeal things are to be placed only in
the various separations and new associations and mo-
tions of these permanent particles; compounded bodies
being apt to break, not in the midst of solid particles,
but where those particles are laid together and only
touch in a few points.'
We shall hereafter see how extensively the atomic
doctrine has prevailed among still more recent philoso-
phers. Not only have the chemists assumed it as the
fittest form for exhibiting the principles of multiple
proportions; but the physical mathematicians, as La-
place and Poisson, have made it the basis of their
theories of heat, electricity, capillary action; and the
crystallographers have been supposed to have esta-
blished both the existence and the arrangement of
such ultimate molecules.
In the way in which it has been employed by such
writers, the hypothesis of ultimate particles has been
of great use, and is undoubtedly permissible. But
when we would assert this theory, not as a convenient
hypothesis for the expression or calculation of the
laws of nature, but as a philosophical truth respecting
the constitution of the universe, we find ourselves
checked by difficulties of reasoning which we cannot
overcome, as well as by conflicting phenomena which
we cannot reconcile. I will attempt to state briefly
the opposing arguments on this question.
8. Arguments for and against Atoms.-The leading
arguments on the two sides of the question, in their
most general form, may be stated as follows:
For the Atomic Doctrine.-The appearances which
nature presents are compounded of many parts, but if
we go on resolving the larger parts into smaller, and
so on successively, we must at last come to something
simple. For that which is compound can be so no
otherwise than by composition of what is simple; and
if we suppose all composition to be removed, which
THE ATOMIC THEORY.
57
hypothetically we may do, there can remain nothing
but a number of simple substances, capable of compo-
sition, but themselves not compounded. That is, matter
being dissolved, resolves itself into atoms.
Against the Atomic Doctrine.-Space is divisible
without limit, as may be proved by Geometry; and
matter occupies space, therefore matter is divisible
without limit, and no portion of matter is indivisible,
or an atom.
And to the argument on the other side just stated,
it is replied that we cannot even hypothetically divest
a body of composition, if by composition we mean the
relation of point to point in space. However small be
a particle, it is compounded of parts having relation in
space.
The Atomists urge again, that if matter be infinitely
divisible, a finite body consists of an infinite number of
parts, which is a contradiction. To this it is replied,
that the finite body consists of an infinite number of
parts in the same sense in which the parts are infi-
nitely small, which is no contradiction.
But the opponents of the Atomists not only rebut,
but retort this argument drawn from the notion of
infinity. Your atoms, they say, are indivisible by any
finite force; therefore they are infinitely hard; and
thus your finite particles possess infinite properties.
To this the Atomists are wont to reply, that they do
not mean the hardness of their particles to be infinite,
but only so great as to resist all usual natural forces.
But here it is plain that their position becomes unten-
able; for, in the first place, their assumption of this
precise degree of hardness in the particles is altogether
gratuitous; and in the next place, if it were granted,
such particles are not atoms, since in the next moment
the forces of nature may be augmented so as to divide
the particle, though hitherto undivided.
Such are the arguments for and against the Atomic
Theory in its original form. But when these atoms
are conceived, as they have been by Newton, and com-
monly by his followers, to be solid, hard particles
exerting attractive and repulsive forces, a new set of
58
PHILOSOPHY OF CHEMISTRY.
arguments come into play. Of these, the principal
one may be thus stated: According to the Atomic
Theory thus modified, the properties of bodies depend
upon the attractions and repulsions of the particles.
Therefore, among other properties of bodies, their hard-
ness depends upon such forces. But if the hardness of
the bodies depends upon the forces, the repulsion, for
instance, of the particles, upon what does the hardness
of the particles depend? what progress do we make in
explaining the properties of bodies, when we assume
the same properties in our explanation? and to what
purpose do we assume that the particles are hard?
9. Transition to Boscovich's Theory.-To this diffi-
culty it does not appear easy to offer any reply. But
if the hardness and solidity of the particles be given
up as an incongruous and untenable appendage to the
Newtonian view of the Atomic Theory, we are led to
the theory of Boscovich, according to which matter
consists not of solid particles, but of mere mathematical
centers of force. According to this theory, each body
is composed of a number of geometrical points from
which emanate forces, following certain mathematical
laws in virtue of which the forces become, at certain
small distances attractive, at certain other distances
repulsive, and at greater distances attractive again.
From these forces of the points arise the cohesion of
the parts of the same body, the resistance which it
exerts against the pressure of another body, and finally
the attraction of gravitation which it exerts upon bodies
at a distance.
This theory is at least a homogeneous and consistent
theory, and it is probable that it may be used as an
instrument for investigating and expressing true laws
of nature; although, as we have already said, the
attempt to identify the forces by which the particles
of bodies are bound together with mechanical attrac-
tion, appears to be a confusion of two separate ideas.
5
'Boscovich's Theory,' that all
bodies may be considered as consist-
ing of a mere collection of centers of
forces, may be so conceived as pos-
sibly to involve an explanation of all
the powers which their parts exert,
THE ATOMIC THEORY.
59
10. Use of the Molecular Hypothesis.—In this form,
representing matter as a collection of molecules or
centers of force, the Atomic Theory has been abund-
antly employed in modern times as an hypothesis on
which calculations respecting the elementary forces of
bodies might be conducted. When thus employed it is
to be considered as expressing the principle that the
properties of bodies depend upon forces emanating
from immovable points of their mass.
This view of
the way in which the properties of bodies are to be
treated by the mechanical philosopher was introduced
by Newton, and was a natural sequel to the success
which he had obtained by reasoning concerning central
forces on a large scale. I have already quoted his
Preface to the Principia, in which he says, 'Many
things induce me to believe that the rest of the pheno-
mena of nature, as well as those of astronomy, may
depend upon certain forces by which the particles of
bodies, in virtue of causes not yet known, are urged
towards each other and cohere in regular figures, or
are mutually repelled and recede; and philosophers,
knowing nothing of these forces, have hitherto failed
in their examination of nature.' Since the time of
Newton, this line of speculation has been followed
with great assiduity, and by some mathematicians
with great success. In particular Laplace has shown
that the hypothesis may, in many instances, be made
a much closer representation of nature, if we sup-
pose the forces exerted by the particles to decrease so
rapidly with the increasing distance from them, that
(such powers, namely, as those which
produce optical, thermotical and che-
mical phenomena;) but this theory
cannot supply an explanation of the
mechanical properties of a body as a
whole, especially of its inertia. Acol-
lection of mere centers of force can
have no inertia. If two bodies are con-
sidered as two collections of centers of
force,the one attracting the other, there
is in this view nothing to limit or de-
termine the velocity with which the
one body will approach the other.
A world composed of such bodies is
not a material world: for matter (as
we have already seen in book iii.
chapter v.) implies not only force,
but something which resists the ac-
tion of force.
60
PHILOSOPHY OF CHEMISTRY.
the force is finite only at distances imperceptible to
our senses, and vanishes at all remoter points. He has
taught the method of expressing and calculating such
forces, and he and other mathematicians of his school
have applied this method to many of the most import-
ant questions of physics; as capillary action, the elas-
ticity of solids, the conduction and radiation of heat.
The explanation of many apparently unconnected and
curious observed facts by these mathematical theories
gives a strong assurance that its essential principles
are true. But it must be observed that the actual
constitution of bodies as composed of distinct and
separate particles is by no means proved by these
coincidences. The assumption, in the reasoning, of
certain centers of force acting at a distance, is to be
considered as nothing more than a method of reducing
to calculation that view of the constitution of bodies
which supposes that they exert force at every point.
It is a mathematical artifice of the same kind as the
hypothetical division of a body into infinitesimal
parts, in order to find its center of gravity; and no
more implies a physical reality than that hypothesis
does.
11. Poisson's Inference.-When, therefore, M. Pois-
son, in his views of Capillary Action, treats this hypo-
thetical distribution of centers of force as if it were
a physical fact, and blames Laplace for not taking
account of their different distribution at the surface of
the fluid and below it, he appears to push the claims
of the molecular hypothesis too far. The only ground
for the assumption of separate centers, is that we can
thus explain the action of the whole mass. The in-
tervals between the centers nowhere enter into this
explanation: and therefore we can have no reason for
assuming these intervals different in one part of the
fluid and in the other. M. Poisson asserts that the
density of the fluid diminishes when we approach very
near the surface; but he allows that this diminution is
not detected by experiment, and that the formulæ on
6 Poisson, Théorie de l'Action Capillaire.
THE ATOMIC THEORY.
61
•
his supposition, so far as the results go, are identical
with those of Laplace. It is clear, then, that his doc-
trine consists merely in the assertion of the necessary
truth of a part of the hypothesis which cannot be put
to the test of experiment. It is true, that so long as
we have before us the hypothesis of separate centers,
the particles very near the surface are not in a condi-
tion symmetrical with that of the others: but it is
also true that this hypothesis is only a step of calcula-
tion. There results, at one period of the process of
deduction, a stratum of smaller density at the surface
of the fluid; but at a succeeding point of the reasoning
the thickness of this stratum vanishes; it has no phy-
sical existence.
Thus the molecular hypothesis, as used in such
cases, does not differ from the doctrine of forces acting
at every point of the mass; and this principle, which
is common to both the opposite views, is the true part
of each.
12. Wollaston's Argument.-An attempt has been
made in another case, but depending on nearly the
same arguments, to bring the doctrine of ultimate
atoms to the test of observation. In the case of the
air, we know that there is a diminution of density in
approaching the upper surface of the atmosphere, if it
have a surface: but it is held by some that except we
allow the doctrine of ultimate molecules, it will not
be bounded by any surface, but will extend to an in-
finite distance. This is the reasoning of Wollaston".
'If air consists of any ultimate particles no longer
divisible, then must the expansion of the medium
composed of them cease at that distance where the
force of gravity downwards is equal to the resistance
arising from the repulsive force of the medium.'
if there be no such ultimate particles, every stratum
will require a stratum beyond it to prevent by its
weight a further expansion, and thus the atmosphere
But
7 Phil. Trans. 1822, p. 89.
62
PHILOSOPHY OF CHEMISTRY.
must extend to an infinite distance. And Wollaston
conceived that he could learn from observation whether
the atmosphere was thus diffused through all space;
for if so, it must, he argued, be accumulated about the
larger bodies of the system, as Jupiter and the Sun,
by the law of universal gravitation; and the existence
of an atmosphere about these bodies, might, he re-
marked, be detected by its effects in producing refrac-
tion. His result is, that all the phenomena accord
entirely with the supposition that the earth's atmo-
sphere is of finite extent, limited by the weight of
ultimate atoms of definite magnitude, no longer divi-
sible by repulsion of their parts.'
6
A very little reflection will show us that such a line
of reasoning cannot lead to any result. For we know
nothing of the law which connects the density with
the compressing force, in air so extremely rare as we
must suppose it to be near the boundary of the atmo-
sphere. Now there are possible laws of dependence
of the density upon the compressing force such that
the atmosphere would terminate in virtue of the law
without any assumption of atoms. This may be proved
by mathematical reasoning. If we suppose the density
of air to be as the square root of the compressing
force, it will follow that at the very limits of the atmo-
sphere, the strata of equal thickness may observe in
their densities such a law of proportion as is expressed
by the numbers 7, 5, 3, 18.
If it be asked how, on this hypothesis, the density
of the highest stratum can be as 1, since there is no-
s For the compressing force on
each being as the whole weight be-
yond it, it will be for the four highest
strata, 16, 9, 4 and 1, of which the
square roots are as 4, 3, 2, 1, or, as
8, 6, 4, 2; and though these numbers
are not exactly as the densities
7, 5, 3, 1, those who are a little
acquainted with mathematical rea-
soning, will see that the difference
arises from taking so small a number
of strata. If we were to make the
strata indefinitely thin, as to avoid
error we ought to do, the coincidence
would be exact; and thus, according
to this law, the series of strata ter-
minates as we ascend, without any
consideration of atoms.
THE ATOMIC THEORY.
63
thing to compress it, we answer that the upper part of
the highest stratum compresses the lower, and that the
density diminishes continually to the surface, so that
the need of compression and the compressing weight
vanish together.
The fallacy of concluding that because the height
of the atmosphere is finite, the weight of the highest
stratum must be finite, is just the same as the fallacy
of those who conclude that when we project a body
vertically upwards, because it occupies only a finite
time in ascending to the highest point, the velocity at
the last instant of the ascent must be finite. For it
might be said, if the last velocity of ascent be not
finite, how can the body describe the last particle of
space in a finite time? and the answer is, that there is
no last finite particle of space, and therefore no last
finite velocity.
He
13. Permanence of Properties of Bodies. We have
already seen that, in explaining the properties of mat-
ter as we find them in nature, the assumption of solid,
hard, indestructible particles is of no use or value.
But we may remark, before quitting the subject, that
Newton appears to have had another reason for assum-
ing such particles, and one well worthy of notice.
wished to express, by means of this hypothesis, the
doctrine that the laws of nature do not alter with the
course of time. This we have already seen in the
quotation from Newton. "The ultimate particles of
matter are indestructible, unalterable, impenetrable;
for if they could break or wear, the structure of mate-
rial bodies now would be different from that which
it was when the particles were new.' No philosopher
will deny the truth which is thus conveyed by the
assertion of atoms; but it is obviously equally easy
for a person who rejects the atomic view, to state this
truth by saying that the forces which matter exerts
do not vary with time, but however modified by the
new modifications of its form, are always unimpaired
in quantity, and capable of being restored to their
former mode of action.
64
PHILOSOPHY OF CHEMISTRY.
We now proceed to speculations in which the funda-
mental conceptions may, perhaps, be expressed, at
least in some cases, by means of the arrangement of
atoms; but in which the philosophy of the subject
appears to require a reference to a new Fundamental
Idea.
BOOK VII.
THE
PHILOSOPHY
OF
MORPHOLOGY,
INCLUDING
CRYSTALLOGRAPHY.
VOL. II.
F
CRYSTALLIZATION exhibits to us the effects of the natural
arrangement of the ultimate particles of various compound
bodies;
but we are scarcely yet sufficiently acquainted with
chemical synthesis and analysis to understand the rationale of
this process. The rhomboidal form may arise from the pro-
per position of 4, 6, 8 or 9 globular particles, the cubic form
from 8 particles, the triangular form from 3, 6 or 10 particles,
the hexahedral prism from 7 particles, &c. Perhaps, in due time
we may be enabled to ascertain the number and order of ele-
mentary particles, constituting any given compound element, and
from that determine the figure which it will prefer on crystalliza-
tion, and vice versâ.
JOHN DALTON, Chemical Philosophy (1808), p. 210.
BOOK VII.
THE PHILOSOPHY OF MORPHOLOGY, INCLUDING
CRYSTALLOGRAPHY.
CHAPTER I.
EXPLICATION OF THE IDEA OF SYMMETRY.
I.
WE
E have seen in the History of the Sciences,
that the principle which I have there termed'
the Principle of Developed and Metamorphosed Symme-
try, has been extensively applied in botany and physio-
logy, and has given rise to a province of science
termed Morphology. In order to understand clearly
this principle, it is necessary to obtain a clear idea of
the Symmetry of which we thus speak. But this Idea
of Symmetry is applicable in the inorganic, as well as
in the organic kingdoms of nature; it is presented to
our eyes in the forms of minerals, as well as of flowers
and animals; we must, therefore, take it under our
consideration here, in order that we may complete our
view of Mineralogy, which, as I have repeatedly said,
is an essential part of Chemical science. I shall accord-
ingly endeavour to unfold the Idea of Symmetry with
which we here have to do.
It will of course be understood that by the term
Symmetry I here intend, not that more indefinite attri-
bute of form which belongs to the domain of the fine
arts, as when we speak of the 'symmetry' of an edifice
1 Hist. Ind. Sc. b. xvii. c. vi.
F 2
68
PHILOSOPHY OF MORPHOLOGY.
or of a sculptured figure, but a certain definite relation
or property, no less rigorous and precise than other
relations of number and position, which is thus one of
the sure guides of the scientific faculty, and one of the
bases of our exact science.
2. In order to explain what Symmetry is in this
sense, let the reader recollect that the bodies of animals
consist of two equal and similar sets of members, the
right and the left side;—that some flowers consist of
three or of five equal sets of organs, similarly and re-
gularly disposed, as the iris has three straight petals,
and three reflexed ones, alternately disposed, the rose
has five equal and similar sepals of the calyx, and alter-
nate with these, as many petals of the corolla. This
orderly and exactly similar distribution of two, or three,
or five, or any other number of parts, is Symmetry; and
according to its various modifications, the forms thus
determined are said to be symmetrical with various
numbers of members. The classification of these dif-
ferent kinds of symmetry has been most attended to in
Crystallography, in which science it is the highest and
most general principle by which the classes of forms
are governed. Without entering far into the techni-
calities of the subject, we may point out some of the
features of such classes.
1
The first of the figures
(1) in the margin may
represent the summit of
a crystal as it appears to
an eye looking directly
down upon it; the center
of the figure represents
the summit of a pyramid, and the spaces of various
forms which diverge from this point represent sloping
sides of the pyramid. Now it will be observed that
the figure consists of three portions exactly similar to
one another, and that each part or member is repeated
in each of these portions. The faces, or pairs of faces,
are repeated in threes, with exactly similar forms and
angles. This figure is said to be three-membered, or to
have triangular symmetry. The same kind of sym-


EXPLICATION OF THE IDEA OF SYMMETRY. 69
metry may exist in a flower, as presented in the accom-
panying figure, and does, in fact, occur in a large class
of flowers, as for example, all the lily tribe. The next
pair of figures (2) have four equal and similar portions,
and have their members
or pairs of members four
times repeated. Such
figures are termed four-
membered, and are said
to have square or tetra-
gonal symmetry. The
pentagonal symmetry,
formed by five similar
members, is represented
in the next figures (3).
It occurs abundantly in
the vegetable world, but
never among crystals;
for the pentagonal fi-
gures which crystals
sometimes assume, are
never exactly regular.
But there is still ano-
ther kind of symmetry
(4) in which the oppo-
site ends are exactly
similar to each other
and also the opposite
sides; this is oblong, or
two-and-two-membered
symmetry. And finally,
we have the case of sim-
ple symmetry (5) in
which the two sides of
the object are exactly
alike (in opposite posi-
tions) without any fur-
ther repetition.


2


3


4
5
食
​

3. These different kinds of symmetry occur in
various ways in the animal, vegetable, and mineral
kingdom. Vertebrate animals have a right and a
70
PHILOSOPHY OF MORPHOLOGY.
left side exactly alike, and thus possess simple symme-
try. The same kind of symmetry (simple symmetry)
occurs very largely in the forms of vegetables, as in
most leaves, in papilionaceous, personate, and labiate
flowers. Among minerals, crystals which possess this
symmetry are called oblique-prismatic, and are of very
frequent occurrence. The oblong, or two-and-two-mem-
bered symmetry belongs to right-prismatic crystals; and
may be seen in cruciferous flowers, for though these
are cross-shaped, the cross has two longer and two
shorter arms, or pairs of arms. The square or tetra-
gonal symmetry occurs in crystals abundantly; to the
vegetable world it appears to be less congenial; for
though there are flowers with four exactly similar
and regularly-disposed petals, as the herb Paris (Paris
quadrifolia), these flowers appear, from various circum-
stances, to be deviations from the usual type of vege-
table forms. The trigonal, or three-membered symmetry
is found abundantly both in plants and in crystals,
while the pentagonal symmetry, on the other hand,
though by far the most common among flowers,
nowhere occurs in minerals, and does not appear to be
a possible form of crystals. This pentagonal form
further occurs in the animal kingdom, which the
oblong, triangular, and square forms do not. Many
of Cuvier's radiate animals appear in this pentagonal
form, as echini and pentacrinites, which latter have
hence their name.
4. The regular, or as they may be called, the normal
types of the vegetable world appear to be the forms
which possess triangular and pentagonal symmetry;
from these the others may be conceived to be derived,
by transformations resulting from the expansion of one
or more parts. Thus it is manifest that if in a three-
membered or five-membered flower, one of the petals
be expanded more than the other, it is immediately
reduced from pentagonal or trigonal, to simple sym-
metry. And the oblong or two-and-two-membered
symmetry of the flowers of cruciferous plants, (in which
the stamens are four large and two small ones, arranged
in regular opposition,) is held by botanists to result
EXPLICATION OF THE IDEA OF SYMMETRY. 71
from a normal form with ten stamens; Meinecke ex-
plaining this by adhesion, and Sprengel by the meta-
morphosis of the stamens into petals².
It is easy to see that these various kinds of sym-
metry include relations both of form and of number,
but more especially of the latter kind; and as this
symmetry is often an important character in various
classes of natural objects, such classes have often
curious numerical properties. One of the most re-
markable and extensive of these is the distinction
which prevails between monocotyledonous and dicoty-
ledonous plants; the number three being the ground of
the symmetry of the former, and the number five, of
the latter. Thus liliaceous and bulbous plants, and the
like, have flowers of three or six petals, and the other
organs follow the same numbers: while the vast ma-
jority of plants are pentandrous, and with their five
stamens have also their other parts in fives. This great
numerical distinction corresponding to a leading differ-
ence of physiological structure cannot but be considered
as a highly curious fact in phytology. Such properties
of numbers, thus connected in an incomprehensible
manner with fundamental and extensive laws of nature,
give to numbers an appearance of mysterious import-
ance and efficacy. We learn from history how strongly
the study of such properties, as they are exhibited by
the phenomena of the heavens, took possession of the
mind of Kepler; perhaps it was this which, at an
earlier period, contributed in no small degree to the
numerical mysticism of the Pythagoreans in antiquity,
and of the Arabians and others in the middle ages. In
crystallography, numbers are the primary characters
in which the properties of substances are expressed;-
they appear, first, in that classification of forms which
depends on the degree of symmetry, that is, upon the
number of correspondencies; and next, in the laws of
derivation, which, for the most part, appear to be com-
mon in their occurrence in proportion to the numerical
simplicity of their expression. But the manifestation
2 Sprengel, Gesch. d. Bot. ii. 304.
72
PHILOSOPHY OF MORPHOLOGY.
of a governing numerical relation in the organic world
strikes us as more unexpected; and the selection
of the number five as the index of the symmetry of
dicotyledonous plants and radiated animals, (a number
which is nowhere symmetrically produced in inorganic
bodies,) makes this a new and remarkable illustration
of the constancy of numerical relations. We may ob-
serve, however, that the moment one of these radiate
animals has one of its five members expanded, or in
any way peculiarly modified, (as happens among the
echini), it is reduced to the common type of animals
simply symmetrical, with a right and left side.
5. It is not necessary to attempt to enumerate all
the kinds of Symmetry, since our object is only to ex-
plain what Symmetry is, and for this purpose enough
has probably been said already. It will be seen, as
soon as the notion of Symmetry in general is well ap-
prehended, that it is or includes a peculiar Funda-
mental Idea, not capable of being resolved into any of
the ideas hitherto examined. It may be said, perhaps,
that the Idea of Symmetry is a modification or deriva-
tive of our ideas of space and number;--that a symme-
trical shape is one which consists of parts exactly
similar, repeated a certain number of times, and placed
so as to correspond with each other. But on further
reflection it will be seen that this repetition and corre-
spondence of parts in symmetrical figures are some-
thing peculiar; for it is not any repetition or any
correspondence of parts to which we should give the
name of symmetry, in the manner in which we are
now using the term. Symmetrical arrangements may,
no doubt, be concerned with space and position, time
and number; but there appears to be implied in them
a Fundamental Idea of regularity, of completeness, of
complex simplicity, which is not a mere modification of
other ideas.
6. It is, however, not necessary, in this and in
similar cases, to determine whether the idea which we
have before us be a peculiar and independent Funda-
mental Idea or a modification of other ideas, provided
we clearly perceive the evidence of those Axioms by
EXPLICATION OF THE IDEA OF SYMMETRY. 73
means of which the Idea is applied in scientific reason-
ings. Now in the application of the Idea of Symmetry
to crystallography, phytology and zoology, we must
have this idea embodied in some principle which asserts
more than a mere geometrical or numerical accordance
of members. We must have it involved in some vital
or productive action, in order that it may connect and
explain the facts of the organic world. Nor is it diffi-
cult to enunciate such a principle. We may state it
in this manner. All the symmetrical members of a
natural product are, under like circumstances, alike
affected by the natural formative power. The parts
which we have termed symmetrical, resemble each
other, not only in their form and position, but also in
the manner in which they are produced and modified
by natural causes. And this principle we assume to
be necessarily true, however unknown and inconceiv-
able may be the causes which determine the pheno-
mena. Thus it has not yet been found possible to dis-
cover or represent to ourselves, in any intelligible
manner, the forces by which the various faces of a
crystal are consequent upon its primary form: for the
hypothesis of their being built up of integrant mole-
cules, as Haüy held, cannot be made satisfactory. But
though the mechanism of crystals is still obscure, there
is no doubt as to the principle which regulates their
modifications. The whole of crystallography rests upon
this principle, that if one of the primary planes or axes
be modified in any manner, all the symmetrical planes,
and axes must be modified in the same manner. And
though accidental mechanical or other causes may inter-
fere with the actual exhibition of such faces, we do not
the less assume their crystallographical reality, as in-
evitably implied in the law of symmetry of he crystal³.
And we apply similar considerations to organized beings.
We assume that in a regular flower, each of the similar
3 Some crystalline forms, instead
of being holohedral (provided with
their whole number of faces), are
hemihedral (provided with only half
their nuznber of faces). But in these
hemihedral forms the half of the
facres are still symmetrically sup-
pressed.
74
PHILOSOPHY OF MORPHOLOGY.
members has the same organization and similar powers
of developement; and hence if among these similar parts
some are much less developed than others, we consider
them as abortive; and if we wish to remove doubts as
to what are symmetrical members in such a case, we
make the inquiry by tracing the anatomy of these
members, or by following them in their earlier states
of developement, or in cases where their capabilities are
magnified by monstrosity or otherwise. The power of
developement may be modified by external causes, and
thus we may pass from one kind of symmetry to an-
other; as we have already remarked. Thus a regular
flower with pentagonal symmetry, growing on a lateral
branch, has one petal nearest to the axis of the plant :
if this petal be more or less expanded than the others,
the pentagonal symmetry is interfered with, and the
flower may change to a symmetry of another kind.
But it is easy to see that all such conceptions of expan-
sion, abortion, and any other kind of metamorphosis, go
upon the supposition of identical faculties and tenden-
cies in each similar member, in so far as such tenden-
cies have any relation to the symmetry. And thus the
principle we have stated above is the basis of that
which, in the History, we termed the Principle of
Developed and Metamorphosed Symmetry.
We shall not at present pursue the other applica-
tions of this Idea of Symmetry, but we shall consider
some of the results of its introduction into Crystallo-
graphy.
CHAPTER II.
APPLICATION OF THE IDEA OF SYMMETRY TO
CRYSTALS.
I.
M
INERALS and other bodies of definite che-
mical composition often exhibit that marked
regularity of form and structure which we designate
by terming them Crystals; and in such crystals, when
we duly study them, we perceive the various kinds of
symmetry of which we have spoken in the previous
chapter. And the different kinds of symmetry which
we have there described are now usually distinguished
from each other, by writers on crystallography. Indeed
it is mainly to such writers that we are indebted for
a sound and consistent classification of the kinds and
degrees of symmetry of which forms are capable. But
this classification was by no means invented as soon as
mineralogists applied themselves to the study of cry-
stals. These first attempts to arrange crystalline forms
were very imperfect; those, for example, of Linnæus,
Werner, Romé de Lisle, and Haüy. The essays of
these writers implied a classification at once defective
and superfluous. They reduced all crystals to one or
other of certain fundamental forms; and this proce-
dure might have been a perfectly good method of
díviding crystalline forms into classes, if the funda-
mental forms had been selected so as to exemplify the
different kinds of symmetry. But this was not the
case. Haüy's fundamental or 'primitive' forms, were,
for instance, the following: the parallelepiped, the
octahedron, the tetrahedron, the regular hexagonal
prism, the rhombic dodecahedron, and the double hexa-
gonal pyramid. Of these, the octahedron, the tetra-
hedron, the rhombic dodecahedron, all belong to the
76
PHILOSOPHY OF MORPHOLOGY.
same kind of symmetry (the TESSULAR systems); also
the hexagonal prism and the hexagonal pyramid both
belong to the RHOMBIC system; while the parallelepiped
is so employed as to include all kinds of symmetry.
It is, however, to be recollected that Haüy, in his
selection of primitive forms, not only had an eye to
the external form of the crystal and to its degree and
kind of regularity, but also made his classification
with an especial reference to the cleavage of the mine-
ral, which he considered as a primary element in
crystalline analysis. There can be no doubt that the
cleavage of a crystal is one of its most important cha-
racters: it is a relation of form belonging to the
interior, which is to be attended to no less than the
form of the exterior. But still, the cleavage is to be
regarded only as determining the degree of geometrical
symmetry of the body, and not as defining a special
geometrical figure to which the body must be referred.
To have looked upon it in the latter light, was a mis-
take of the earlier crystallographic speculators, on
which we shall shortly have to remark.
2. I have said that the reference of crystals to Pri-
mitive Forms might have been well employed as a
mode of expressing a just classification of them. This
follows as a consequence from the application of the
Principle stated in the last chapter, that all symmetri-
cal members are alike affected. Thus we may take an
upright triangular prism as the representative of the
rhombic system, and if we then suppose one of the
upper edges to be cut off, or truncated, we must, by
the Principle of Symmetry, suppose the other two
upper edges to be truncated in precisely the same
manner. By this truncation we may obtain the upper
part of a rhombohedron; and by truncations of the
same kind, symmetrically affecting all the analogous
paris of the figure, we may obtain any other form
possessing three-membered symmetry. And the same
is true of any of the other kinds of symmetry, pro-
vided we make a proper selection of a fundamental
form. And this was really the method employed
by Demeste, Werner, and Romé de Lisle. They
IDEA OF SYMMETRY IN CRYSTALS.
77
assumed a Primitive Form, and then conceived other
forms, such as they found in nature, to be derived
from the Primitive Form by truncation of the edges,
acumination of the corners, and the like processes.
This mode of conception was a perfectly just and legi-
timate expression of the general Idea of Symmetry.
3. The true view of the degrees of symmetry was,
as I have already said, impeded by the attempts which
Haüy and others made to arrive at primitive forms by
the light which cleavage was supposed to throw upon
the structure of minerals. At last, however, in Ger-
many, as I have narrated in the History of Mineralogy',
Weiss and Mohs introduced a classification of forms
implying a more philosophical principle, dividing the
forms into Systems; which, employing the terms of
the latter writer, we shall call the tessular, the pyra-
midal or square pyramidal, the prismatic or oblong,
and the rhombohedral systems.
Of these forms, the three latter may be at once re-
ferred to those kinds of symmetry of which we have
spoken in the last chapter. The rhombohedral system
has triangular symmetry, or is three-membered: the
pyramidal has square symmetry, or is four-membered :
the prismatic has oblong symmetry, and is two-and-two-
membered. But the kinds of symmetry which were
spoken of in the former chapter, do not exhaust the
idea when applied to minerals. For the symmetry
which was there explained was such only as can be
exhibited on a surface, whereas the forms of crystals
are solid. Not only have the right and left parts of
the upper surface of a crystal relations to each other;
but the upper surface and the lateral faces of the
crystal have also their relations; they may be different,
or they may be alike. If we take a cube, and hold it
so that four of its faces are vertical, not only are all
these four sides exactly similar, so as to give square
symmetry; but also we may turn the cube, so that any
one of these four sides shall become the top, and still
the four sides which are thus made vertical, thoug

1 Hist. Ind. Sc. b. xv. c. iv.
78
PHILOSOPHY OF MORPHOLOGY.
*
not the same which were vertical before, are still per-
fectly symmetrical. Thus this cubical figure possesses
more than square symmetry. It possesses square
symmetry in a vertical as well as in a horizontal sense.
It possesses a symmetry which has the same relation
to a cube which four-membered symmetry has to a
square. And this kind of symmetry is termed the
cubical or tessular symmetry. All the other kinds of
symmetry have reference to an axis, about which the
corresponding parts are disposed; but in tessular sym-
metry the horizontal and vertical axes are also symme-
trical, or interchangeable; and thus the figure may be
said to have no axis at all.
4. It has already been repeatedly stated that, by
the very idea of symmetry, all the incidents of form
must affect alike all the corresponding parts. Now in
crystals we have, among these incidents, not only
external figure, but cleavage, which may be considered
as internal figure. Cleavage, then, must conform to
the degree of symmetry of the figure. Accordingly
cleavage, no less than forin, is to be attended to in
determining to what system a mineral belongs. If a
crystal were to occur as a square prism or pyramid, it
would not on that account necessarily belong to the
square pyramidal system. If it were found that it
was cleavable parallel to one side of the prism, but not
in the transverse direction, it has only oblong symme-
try; and the equality of the sides which makes it
square is only accidental.
Thus no cleavage is admissible in any system of
crystallization which does not agree with the degree of
symmetry of the system. On the other hand, any
cleavage which is consistent with the symmetry of the
system, is (hypothetically at least) allowable. Thus in
the oblong prismatic system we may have a cleavage
parallel to one side only of the prism; or parallel to
both, but of different distinctness; or parallel to the
two diagonals of the prism but of the same distinct-
ess; or we may have both these cleavages together.
the rhombohedral system, the cleavage may be
to the sides of the rhombohedron, as in Cale

IDEA OF SYMMETRY IN CRYSTALS.
79
Spar: or, in the same system, the cleavage, instead of
being thus oblique to the axis, may be along the axis
in those directions which make equal angles with each
other this cleavage easily gives either a triangular or
a hexagonal prism. Again, in the tessular system,
the cleavage may be parallel to the surface of the
cube, which is thus readily separable into other cubes,
as in Galena; or the cleavage may be such as to cut
off the solid angle of the cube, and since there are
eight of these, such cleavage gives us an octahedron,
which, however, may be reduced to a tetrahedron, by
rejecting all parallel faces, as being mere repetitions of
the same cleavage; this is the case with Fluor Spar:
or the cube of the tessular system may be cleavable in
planes which truncate all the edges of the cube; and
as these are twelve, we thus obtain the dodecahedron
with rhombic faces: this occurs in Zinc Blende. And
thus we see the origin of Haüy's various primitive
forms, the tetrahedron, octahedron, and rhombic dode-
cahedron, all belonging to the tessular system :-they
are, in fact, different cleavage forms of that system.
5. I do not dwell upon other incidents of crystals
which have reference to form, nor upon the lustre,
smoothness, and striation of the surfaces. To all such
incidents the general principle applies, that similar
parts are similarly affected; and hence, if any parts are
found to be constantly and definitely different from
other parts of the same sort, they are not similar
parts; and the symmetry is to be interpreted with
reference to this difference.
•
We have now to consider the inferences which have
been drawn from these incidents of crystallization,
with regard to the intimate structure of bodies.
CHAPTER III.
SPECULATIONS FOUNDED UPON THE SYMMETRY
OF CRYSTALS.
I.
W
HEN a crystal, as, for instance, a crystal of
Galena, (sulphuret of lead,) is readily divisi-
ble into smaller cubes, and these into smaller ones,
and so on without limit, it is very natural to represent
to ourselves the original cube as really consisting of
small cubical elements; and to imagine that it is a phi-
losophical account of the physical structure of such a
substance to say that it is made up of cubical mole-
cules. And when the Galena crystal has externally
the form of a cube, there is no difficulty in such a con-
ception; for the surface of the crystal is also conceived
as made up of the surfaces of its cubical molecules.
We conceive the crystal so constituted, as we conceive
a wall built of bricks.
But if, as often happens, the Galena crystal be an
octahedron, a further consideration is requisite in order
to understand its structure, pursuing still the same
hypothesis. The mineral is still, as in the other case,
readily cleavable into small cubes, having their corners
turned to the faces of the octahedron. Therefore these
faces can, no longer be conceived as made up of the
faces of cubical elements of which the whole is consti-
tuted. If we suppose a pile of such small cubes to be
closely built together, but with decreasing width above,
so as to form a pyramid, the face of such a pyramid
will no longer be plane; it will consist of a great num-
ber of the corners or edges of the small elementary
cubes. It would appear at first sight, therefore, that
such a face cannot represent the smooth polished sur-
face of a crystal.
SPECULATIONS ON SYMMETRY OF CRYSTALS. 81
But when we come to look more closely, this diffi-
culty disappears. For how large are these elementary
cubes? We cannot tell, even supposing they really
have any size. But we know that they must be, at
any rate, very small; so small as to be inappreciable by
our senses, for our senses find no limit to the divisi-
bility of minerals by cleavage. Hence the surface of
the pyramid above described would not consist of
visible corners or edges, but would be roughened by
specks of imperceptible size; or rather, by supposing
these specks to become still smaller, the roughness
becomes smoothness. And thus we may have a crystal
with a smooth surface, made up of small cubes in such
a manner that their surfaces are all oblique to the sur-
face of the crystal.
Haüy, struck by some instances in which the suppo-
sition of such a structure of crystals appeared to ac-
count happily for several of their relations and proper-
ties, adopted and propounded it as a general theory.
The small elements, of which he supposed crystals to
be thus built up, he termed integrant molecules. The
form of these molecules might or might not be the
same as the primitive form with which his construc-
tion was supposed to begin; but there was, at any rate,
a close connexion between these forms, since both of
them were founded on the cleavage of the mineral.
The tenet that crystals are constituted in the manner
which I have been describing, I shall call the Theory
of Integrant Molecules, and I have now to make some
remarks on the grounds of this theory.
2. In the case of which I have spoken, the mineral
used as the example, Galena, readily splits into cubes,
and cubes are easily placed together so as to fit each
other, and fill the space which they occupy. The same
is the case in the mineral which suggested to Hauy his
theory, namely, Calc Spar. The crystals of this sub-
stance are readily divisible into rhombohedrons, a
form like a brick with oblique angles; and such bricks
can be built together so as to produce crystals of all the
immense varieties of form which Calc Spar presents.
This kind of masonry is equally possible in many other
VOL. II.
G
f
82
PHILOSOPHY OF MORPHOLOGY.
minerals; but as we go through the mineral kingdom
in our survey, we soon find cases which offer difficul-
ties. Some minerals cleave only in two directions,
some in one only; in such cases we cannot by cleavage
obtain an integrant molecule of definite form; one of
its dimensions, at least, must remain indeterminate
and arbitrary. Again, in some instances, we have
more than three different planes of cleavage, as in
Fluor Spar, where we have four. The solid, bounded
by four planes, is a tetrahedron; or if we take four
pairs of parallel faces, an octahedron. But if we
attempt to take either of these forms for our integrant
molecule, we are met by this difficulty: that a collec-
tion of such forms will not fill space. Perhaps this
difficulty will be more readily conceived by the general
reader if it be contemplated with reference to plane
figures. It will readily be seen that a number of
equal squares may be put together so as to fill the
space which they occupy; but if we take a number of
equal regular octagons, we may easily convince our-
selves that no possible arrangement can make them
cover a flat space without leaving blank spots between.
In like manner octahedrons or tetrahedrons cannot be
arranged in solid space so as to fill it. They necessa-
rily leave vacancies. Hence the structure of Fluor
Spar, and similar crystals, was a serious obstacle in the
way of the theory of integrant molecules. That theory
had been adopted in the first instance because por-
tions of the crystal, obtained by cleavage, could be
built up into a solid mass; but this ground of the
theory failed altogether in such instances as I have
described, and hence the theory, even upon the repre-
sentations of its adherents, had no longer any claim to
assent.
The doctrine of Integral Molecules, however, was
by no means given up at once, even in such instances.
In this and in other subjects, we may observe that a
theory, once constructed and carried into detail, has
such a hold upon the minds of those who have been in
the habit of applying it, that they will attempt to up-
hold it by introducing suppositions inconsistent with
SPECULATIONS ON SYMMETRY OF CRYSTALS. 83
the original foundations of the theory. Thus those who
assert the Atomic Theory, reconcile it with facts by
taking the halves of atoms; and thus the Theory of In-
tegrant Molecules was maintained for Fluor Spar, by
representing the elementary octahedrons of which crys-
tals are built up, as touching each other only by the
edges. The contact of surface with surface amongst
integrant molecules had been the first basis of the
theory; but this supposition being here inapplicable,
was replaced by one which made the theory no longer
a representation of the facts (the cleavages), but a
mere geometrical construction. Although, however,
the inapplicability of the theory to such cases was thus,
in some degree, disguised to the disciples of Haüy, it
was plain that, in the face of such difficulties, the
Theory of Integrant Molecules could not hold its place
as a philosophical truth. But it still answered the
purpose (a very valuable one, and one to which crystal-
lography is much indebted,) of an instrument for calcu-
lating the geometrical relations of the parts of crystals
to each other: for the integrant molecules were sup-
posed to be placed layer above layer, each layer as we
ascend, decreasing by a certain number of molecules
and rows of molecules; and the calculation of these
laws of decrement was, in fact, the best mode then
known of determining the positions of the faces.
The
Theory of Decrements served to express and to deter-
mine, in a great number of the most obvious cases, the
laws of phenomena in crystalline forms, though the
Theory of Integrant Molecules could not be maintained
as a just view of the structure of crystals.
3. The Theory of Integrant Molecules, however, in-
volved this just and important principle: that a true
view of the intimate structure of crystals must include
and explain the facts of crystallization, that is, crystal-
line form and cleavage; and that it must take these
into account, according to their degree of Symmetry.
So far all theories concerning the elements of crystals
must agree.
And it was soon seen that this was, in
reality, all that had been established by the investiga-
tions of Hauy and his school. I have already, in the
G2
84
PHILOSOPHY OF MORPHOLOGY.
History, quoted Weiss's reflections on making this
step. 'When in 1809,' he says', 'I published my
Dissertation, I shared the common opinion as to the
necessity of the assumption, and the reality of the ex-
istence of a primitive form, at least in a sense not very
different from the usual sense of the expression.' He
then proceeds to relate that he sought a ground for
such an opinion, independent of the doctrine of Atoms,
which he, in common with a great number of philoso-
phers of that time in his own country, was disposed to
reject, inclining to believe that the properties of bodies
were determined by Forces which acted in them, and
not by Molecules of which they were composed. He
adds, that in pursuing this train of thought, he found,
'that out of his Primitive Forms there was gradually
unfolded to his hands that which really governs them,
and is not affected by their casual fluctuations; namely,
the Fundamental Relations of their Dimensions,' or as
we now may call them, Axes of Symmetry.
reference to these Axes, he found, as he goes on to say,
that 'a multiplicity of internal Oppositions, necessarily
and mutually interdependent, are developed in the
crystalline mass, each Relation having its own Polarity;
so that the Crystalline Character is co-extensive with
these Polarities.' The character of these polarities,
whether manifested in crystalline faces, cleavage, or
any other incidents of crystallization, is necessarily dis-
played in the degree and kind of Symmetry which the
crystal possesses: and thus this Symmetry, in all our
speculations concerning the structure of crystals, neces-
sarily takes the place of that enumeration of Primitive
Forms which were rejected as inconsistent with observed
facts, and destitute of sound scientific principle.
With
I may just notice here what I have stated in the
History of Mineralogy², that the distinction of systems
of crystallization, as introduced by Weiss and Mohs,
was strikingly confirmed by Sir David Brewster's dis-
coveries respecting the optical properties of minerals.
1 Acad. Berlin. 1816, p. 307.
2 Hist. Ind. Sc. b. xv. c. v.
SPECULATIONS ON SYMMETRY OF CRYSTALS. 85
The splendid phenomena which were produced by
passing polarized light through crystals, were found to
vary according as the crystals were of the Rhombohe-
dral, Square Pyramidal, Oblong Prismatic, or Tessular
System. The Optical Symmetry exactly corresponded
with the Geometrical Symmetry. In the two former
Systems were crystals uniaxal in respect of their optical
properties; the oblong prismatic, was biaxal; while in
the tessular, the want of a predominant axis prevented
the phenomena here spoken of from occurring at all.
The optical experiments must have led, and would have
led, to a classification of crystals into the above systems
or something nearly equivalent, even had they not been
already so arranged by attention to their forms.
4. While in Germany Weiss and Mohs with their
disciples, were gradually rejecting what was superfluous
in the previous crystallographical hypotheses, philoso-
phers in England were also trying to represent to
themselves the constitution of crystals in a manner
which should be free from the obviously arbitrary and
untenable fictions of the Haüyian school. These
attempts, however, were not crowned with much suc-
cess.
One mode of representing the structure of crys-
tals which suggested itself, was to reject the polyhedral
forms which Haüy gave to his integrant molecules,
and to conceive the elements of crystals as spheres, the
properties of the crystal being determined not by the
surfaces, but by the position of the elements. This was
done by Wollaston, in the Philosophical Transactions
for 1813. He applied this view to the tessular system,
in which, indeed, the application is not difficult; and
he showed that octahedral and tetrahedral figures may
be deduced from symmetrical arrangements of equal
spherules. But though in doing this, he manifested a
perception of the conditions of the problem, he ap-
peared to lose his hold on the real question when he
tried to pass on to other systems of crystallization.
For he accounted for the rhombohedral system by sup-
posing the spheres changed into spheroids. Such a
procedure involved him in a gratuitous and useless.
hypothesis: for to what purpose do we introduce the
86
PHILOSOPHY OF MORPHOLOGY.
arrangement of atoms (instead of their figure,) as a
mode of explaining the symmetry of the crystalliza-
tion, when at the next step we ascribe to the atom, by
an arbitrary fiction, a symmetry of figure of the same
kind as that which we have to explain? It is just as
easy, and as allowable, to assume an elementary rhom-
bohedron, as to assume elementary spheroids, of which
the rhombohedrons are constructed.
5. Many hypotheses of the same kind might be
adduced, devised both by mineralogists and chemists.
But almost all such speculations have been pursued
with a most surprising neglect of the principle which
obviously is the only sound basis on which they can
proceed. The principle is this:-that All hypotheses
concerning the arrangement of the elementary atoms of
bodies in space must be constructed with reference to the
general facts of crystallization. The truth and im-
portance of this principle can admit of no doubt. For
if we make any hypothesis concerning the mode of
connexion of the elementary particles of bodies, this
must be done with the view of representing to our-
selves the forces which connect them, and the results
of these forces as manifested in the properties of the
bodies. Now the forces which connect the particles
of bodies so as to make them crystalline, are manifestly
chemical forces. It is only definite chemical com-
pounds which crystallize; and in crystals the force of
cohesion by which the particles are held together can-
not in any way be distinguished or separated from the
chemical force by which their elements are combined.
The elements are understood to be combined, precisely
because the result is a definite, apparently homoge-
neous substance. The properties of the compound
bodies depend upon the elements and their mode of
combination; for, in fact, these include everything on
which they can depend. There are no other circum-
stances than these which can affect the properties of
a body. Therefore all those properties which have
reference to space, namely, the crystalline properties,
cannot depend upon anything else than the arrange-
ment of the elementary molecules in space. These
SPECULATIONS ON SYMMETRY OF CRYSTALS. 87
properties are the facts which any hypothesis of the
arrangement of molecules must explain, or at least
render conceivable; and all such hypotheses, all con-
structions of bodies by supposed arrangements of
molecules, can have no other philosophical object than
to account for facts of this kind. If they do not do
this, they are mere arbitrary geometrical fictions, which
cannot be in any degree confirmed or authorised by an
examination of nature, and are therefore not deserving
of any regard.
6. Those philosophers who have endeavoured to
represent the mode in which bodies are constructed by
the combination of their chemical atoms, have often
undertaken to show, not only that the atoms are com-
bined, but also in what positions and configurations
they are combined. And it is truly remarkable, as I
have already said, that they have done this, almost in
every instance, without any consideration of the crys-
talline character of the resulting combinations; from
which alone we receive any light as to the relation of
their elements in space. Thus Dr. Dalton, in his
Elements of Chemistry, in which he gave to the world
the Atomic Theory as a representation of the doctrine
of definite and multiple proportions, also published a
large collection of Diagrams, exhibiting what he con-
ceived to be the configuration of the atoms in a great
number of the most common combinations of chemical
elements. Now these hypothetical diagrams do not in
any way correspond, as to the nature of their symme-
try, with the compounds, as we find them displaying
their symmetry when they occur crystallized. Carbo-
nate of lime has in reality a triangular symmetry,
since it belongs to the rhombohedral system; Dr. Dal-
ton's carbonate of lime would be an oblique rhombic
prism or pyramid. Sulphate of baryta is really two-
and-two membered; Dr. Dalton's diagram makes it
two-and-one membered. Alum is really octahedral or
tessular; but according to the diagram it could not be
So, since the two ends of the atom are not symmetrical.
And the same want of correspondence between the
facts and the hypothesis runs through the whole
88
PHILOSOPHY OF MORPHOLOGY.
system. It need not surprise us that the theoretical
arrangement of atoms does not explain the facts of
crystallization; for to produce such an explanation
would be a second step in science quite as great as the
first, the discovery of the atomic theory in its chemical
sense. But we may allow ourselves to be surprised
that an utter discrepance between all the facts of crys-
tallization and the figures assumed in the theory, did
not suggest any doubt as to the soundness of the mode
of philosophizing by which this part of the theory was
constructed.
7. Some little accordance between the hypothetical
arrangements of chemical atoms and the facts of crys-
tallization, does appear to have been arrived at by
some of the theorists to whom we here refer, although
by no means enough to show a due conviction of the
importance of the principle stated above. Thus Wol-
laston, in the Essay above noticed, after showing that
a symmetrical arrangement of equal spherules would
give rise to octahedral and other tessular figures,
remarks, very properly, that the metals, which are
simple bodies, crystallize in such forms. M. Ampère 3
also, in 1814, published a brief account of an hypo-
thesis of a somewhat similar nature, and stated him-
self to have developed this speculation in a Memoir
which has not yet, so far as I am aware, been published.
In this notice he conceives bodies to be compounded
of molecules, which, arranged in a polyhedral form,
constitute particles. These representative forms of the
particles depend on chemical laws. Thus the particles
of oxygen, of hydrogen, and of azote, are composed
each of four molecules. Hence it is collected that the
particles of nitrous gas are composed of two molecules
of oxygen and two of azote; and similar conclusions
are drawn respecting other substances. These conclu-
sions, though expressed by means of the polyhedrons.
thus introduced, are supported by chemical, rather
than by crystallographical comparisons. The author
does, indeed, appeal to the crystallization of sal ammo-
3 Ann. de Chimie, tom. xc. p. 43.
SPECULATIONS ON SYMMETRY OF CRYSTALS. 89
niac as an argument*; but as all the forms which he
introduces appear to belong to the tessular system of
crystallization, there is, in his reasonings, nothing dis-
tinctive; and therefore nothing, crystallographically
speaking, of any weight on the side of this theory.
8. Any hypothesis which should introduce any
principle of chemical order among the actual forms of
minerals, would well deserve attention. At first sight,
nothing can appear more anomalous than the forms
which occur.
We have, indeed, one broad fact, which
has an encouraging aspect, the tessular forms in which
the pure metals crystallize. The highest degree of
chemical and of geometrical simplicity coincide: irre-
gularity disappears precisely where it is excluded by
the consideration above stated, that the symmetry of
chemical composition must determine the symmetry of
crystalline form 5.
But if we go on to any other class of crystalline
forms, we soon find ourselves lost in our attempts to
4 Ann. de Chimie, tom. xc. p. 83.
5 Inasmuch as this law, that the
simple metals crystallize in tessular
forms, is the most signal example of
that connexion between the chemical
nature of a body and its crystalline
form, I in the former Edition stated
it with as much generality as I could
find any ground for, and I should
have been glad if I could have added
confirmation of the law, derived from
later observations. But the most
recent investigations of crystallogra-
phers appear to have afforded excep-
tions rather than examples of the
rule. Arsenic and Tellurium are
said to be rhombohedral. Antimony,
stated by Haly to be octahedral (and
therefore tessular), has been found by
more modern observers to be rhombo-
hedral. Tin has been obtained by
Professor Miller in beautiful crystals
belonging to the pyramidal system.
Professor Nöggerath has observed in
Zinc, after cooling from fusion, hexa-
gonal cleavage, rendering it probable
that the mineral crystallized in rhom-
bohedrons having their axes vertical,
like ice. G. Rose conceives it highly
probable that Osmium and Iridium
are rhombohedral. (Poggendorf. Bd.
liv.)
But all the more perfect metals are
tessular; namely, Gold, Silver, Mer-
cury, Platinum, Iron, Copper; also
Bismuth [?] Perhaps the observation
in which the crystallization of Zinc
is affected by its position is, on that
very account, no sufficient evidence
of its free crystallization. We can
hardly conceive a collection of per-
fectly simple, similar particles to
crystallize so as to have one pre-
eminent axis, without some extra-
neous action affecting them.
90
PHILOSOPHY OF MORPHOLOGY.
follow any thread of order. We have indeed many
large groups connected by obvious analogies; as the
rhombohedral carbonates of lime, magnesia, iron, man-
ganese; the prismatic carbonates and sulphates of
lime, baryta, strontia, lead. But even in these, we
cannot form any plausible hypothesis of the arrange-
ment of the elements; and in other cases to which we
naturally turn, we can find nothing but confusion.
For instance, if we examine the oxides of metals:
those of iron are rhombohedral and tessular; those of
copper, tessular; those of tin, of titanium, of manga-
nese, square pyramidal; those of antimony, prismatic;
and we have other forms for other substances.
It may be added, that if we take account of the
optical properties which, as we have already stated,
have constant relations to the crystalline forms, the
confusion is still further increased; for the optical
dimensions vary in amount, though not in symmetry,
where chemistry can trace no difference of compo-
sition.
9. We will not quit the subject, however, without
noticing the much more promising aspect which it has
assumed by the detection of such groups as are referred
to in the last article; or in other words, by Mitscher-
lich's discovery of Isomorphism. According to that
discovery, there are various elements which may take
the place of each other in crystalline bodies, either
without any alteration of the crystalline form, or at
most with only a slight alteration of its dimensions.
Such a group of elements we have in the earths lime
and magnesia, the protoxides of iron and manganese:
for the carbonates of all these bases occur crystallized
in forms of the rhombohedral system, the characteris-
tic angle being nearly the same in all. Now lime and
magnesia, by the discoveries of modern chemistry, are
really oxides of metals; and therefore all these carbo-
nates have a similar chemical constitution, while they
have also a similar crystalline form. Whether or no
we can devise any arrangement of molecules by which
this connexion of the chemical and the geometrical
property can be represented, we cannot help consider-
SPECULATIONS ON SYMMETRY OF CRYSTALS. 91
ing the connexion as an extremely important fact in
the constitution of bodies; and such facts are more
likely than any other to give us some intelligible view
of the relations of the ultimate parts of bodies. The
same may be said of all the other isomorphous or ple-
siomorphous groups. For instance, we have a num-
ber of minerals which belong to the same system of
crystallization, but in which the chemical composition
appears at first sight to be very various: namely, spi-
nelle, pleonaste, gahnite, franklinite, chromic iron
oxide, magnetic iron oxide: but Abich has shown that
all these may be reduced to a common chemical for-
mula;-they are bioxides of one set of bases, combined
with trioxides of another set. Perhaps some mathema-
tician may be able to devise some geometrical arrange-
ment of such a group of elements which may possess
the properties of the tessular system. Hypothetical
arrangements of atoms, thus expressing both the che-
mical and the crystalline symmetry which we know
to belong to the substance, would be valuable steps in
analytical science; and when they had been duly veri-
fied, the hypotheses might easily be divested of their
atomic character.
Thus, as we have already said, mineralogy, under-
stood in its wider sense, as the counterpart of chemis-
try, has for one of its main objects to discover those
Relations of the Elements of bodies which have refer-
ence to Space. In this research, the foundation of all
sound speculation is the kind and degree of Symmetry
of form which we find in definite chemical compounds:
and the problem at present before the inquirer is, to
devise such arrangements of molecules as shall answer
the conditions alike of Chemistry and of Crystallo-
graphy.
We now proceed to the Classificatory Sciences, of
which Mineralogy is one, though hitherto by far the
least successful.
• See Hist. Ind. Sc. b. xv. c. vi.

BOOK VIII.
THE
PHILOSOPHY
OF THE
CLASSIFICATORY SCIENCES.
:
WHERE a certain apparent difference between things (although
perhaps in itself of little moment) answers to we know not what
number of other differences, pervading not only their known
properties but properties yet undiscovered, it is not optional but
imperative to recognise this difference as the foundation of a
specific distinction.
JOHN S. MILL, System of Logic, b. 1, ch. vii. § 4.
BOOK VIII.
THE PHILOSOPHY OF THE CLASSIFICATORY
SCIENCES.
CHAPTER I.
THE IDEA OF LIKENESS AS GOVERNING THE USE
OF COMMON NAMES.
1. Object of the Chapter.-Nor only the Classifica-
tory Sciences, but the application of names to things
in the rudest and most unscientific manner, depends
upon our apprehending them as like each other.
We
must therefore endeavour to trace the influence and
operation of the Idea of Likeness in the common use
of language, before we speak of the conditions under
which it acquires its utmost exactness and efficacy.
It will be my object to show in this, as in previous
cases, that the impressions of sense are apprehended
by acts of the mind; and that these mental acts neces-
sarily imply certain relations which may be made the
subjects of speculative reasoning. We shall have, if
we can, to seize and bring into clear view the princi-
ples which the relation of like and unlike involves, and
the mode in which these principles have been deve-
loped.
2. Unity of the Individual.—But before we can
attend to several things as like or unlike, we must be
able to apprehend each of these by itself as one thing.
:
96 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
It may at first sight perhaps appear that this appre-
hension results immediately from the impressions on
our senses, without any act of our thoughts. A very
little attention, however, enables us to see that thus to
single out special objects requires a mental operation
as well as a sensation. How, for example, without an
exertion of mental activity, can we see one tree, in a
forest where there are many? We have, spread be-
fore us, a collection of colours and forms, green and
brown, dark and light, irregular and straight: this is
all that sensation gives or can give. But we associate
one brown trunk with one portion of the green mass,
excluding the rest, although the neighbouring leaves
are both nearer in contiguity and more similar in
appearance than is the stem. We thus have before us
one tree; but this unity is given by the mind itself.
We see the green and the brown, but we must make
the tree before we can see it.
That this composition of our sensations so as to
form one thing implies an act of our own, will perhaps
be more readily allowed, if we once more turn our
attention to the manner in which we sometimes attempt
to imitate and record the objects of sight, by drawing.
When we do this, as we have already observed, we
mark this unity of each object, by drawing a line to
separate the parts which we include from those which
we exclude; an Outline. This line corresponds to
nothing which we see; the beginner in drawing has
great difficulty in discerning it; he has in fact to make
it. It is, as has been said by a painter of our own
time¹, a fiction: but it is a fiction employed to mark
a real act of the mind; to designate the singleness of
the object in our conception. As we have said else-
where, we see lines, but especially outlines, by men-
tally drawing them ourselves.
The same act of conception which the outline thus
represents and commemorates in visible objects,—the
same combination of sensible impressions into a unit,
—is exercised also with regard to the objects of all
1 Phillips On Painting,-Design.
THE IDEA OF LIKENESS.
97
our senses: and the singleness thus given to each
object, is a necessary preliminary to its being named
or represented in any other way.
But it may be said, Is it then by an arbitrary act
of our own that we put together the branches of the
same tree, or the limbs of the same animal? Have we
equally the power and the right to make the branch
of the fir a part of the neighbouring oak? Can we
include in the outline of a man any object with which
he happens to be in contact?
Such suppositions are manifestly absurd. And the
answer is, that though we give unity to objects by an
act of thought, it is not by an arbitrary act; but by
a process subject to certain conditions;-to conditions
which exclude such incongruous combinations as have
just been spoken of.
What are these conditions which regulate our ap-
prehension of an object as one?-which determine
what portion of our impressions does, and what por-
tion does not belong to the same thing?
3. Condition of Unity.-I reply, that the primary
and fundamental condition is, that we must be able to
make intelligible assertions respecting the object, and
to entertain that belief of which assertions are the
exposition. A tree grows, sheds its leaves in autumn,
and buds again in the spring, waves in the wind, or
falls before the storm. And to the tree belong all
those parts which must be included in order that such
declarations, and the thought which they convey, shall
have a coherent and permanent meaning. Those are
its branches which wave and fall with its trunk; those
are its leaves which grow on its branches. The perma-
nent connexions which we observe,-permanent, among
unconnected changes which affect the surrounding
appearances, -are what we bind together as belonging
to one object. This permanence is the condition of
our conceiving the object as one. The connected
changes may always be described by means of asser-
tions; and the connexion is seen in the identity of the
subject of successive predications; in the possibility of
applying many verbs to one substantive. We may
VOL. II.
H
98 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
therefore express the condition of the unity of an
object to be this: that assertions concerning the object
shall be possible: or rather we should say, that the acts
of belief which such assertions enunciate shall be pos-
sible.
It may seem to be superfluous to put in a form so
abstract and remote, the grounds of a process appa-
rently so simple as our conceiving an object to be one.
But the same condition to which we have thus been
led, as the essential principle of the unity of objects,
namely, that propositions shall be possible, will re-
peatedly occur in the present chapter; and it may
serve to illustrate our views, to show that this condi-
tion pervades even the simplest cases.
4. Kinds. The mental synthesis of which we have
thus spoken, gives us our knowledge of individual
things; it enables me to apprehend that particular
tree or man which I now see, or, by the help of memory,
the tree or the man I saw yesterday. But the know-
ledge with which we have mainly here to do is not
a knowledge of individuals but of kinds; of such
classes as are indicated by common names. We have
to make assertions concerning a tree or a man in gene-
ral, without regarding what is peculiar to this man or
that tree.
Now it is clear that certain individual objects are
all called man, or all called tree, in virtue of some re-
semblance which they have. If we had not the power
of perceiving in the appearances around us, likeness
and unlikeness, we could not consider objects as distri-
buted into kinds at all. The impressions of sense
would throng upon us, but being uncompared with
each other, they would flow away like the waves of the
sea, and each vanish from our contemplation when the
sensation faded. That we do apprehend surrounding
objects as belonging to permanent kinds, as being men
and horses, oaks and roses, arises from our having the
idea of likeness, and from our applying it habitually,
and so far as such a classification requires.
Not only can we employ the idea of likeness in this
manner, but we apply it incessantly and universally to
THE IDEA OF LIKENESS.
99
the whole mass and train of our sensations. For we
have no external sensations to which we cannot apply
some language or other; and all language necessarily
implies recognition of resemblances. We cannot call
an object green or round without comparing in our
thoughts its colour or its shape, with a shape and
a colour seen in other objects. All our sensations,
therefore, without any exception of kind or time, are
subject to this constant process of classification; and
the idea of likeness is perpetually operating to distri-
bute them into kinds, at least so far as the use of
language requires.
We come then again to the question, Upon what
principle, under what conditions, is the Idea of Likeness
thus operative? What are the limits of the classes
thus formed? Where does that similarity end, which
induces and entitles us to call a thing a tree? What
universal rule is there for the application of common
names, so that we may not apply them wrongly?
5. Not made by Definitions.-Perhaps some one
might expect in answer to these inquiries a definition
or a series of definitions;-might imagine that some
description of a tree might be given which might show
when the term was applicable and when it was not;
and that we might construct a body of rules to which
such descriptions must conform. But on consideration
it will be clear that the real solution of our difficulty
cannot be obtained in such a manner. For first; such
descriptions must be given in words, and must therefore
suppose that we have already satisfied ourselves how
words are to be used. If we define a tree to be 'a
living thing without the power of voluntary motion,"
we shall be called upon to define 'a living thing;' and
it is manifest that this renewal of the demand for
definition might be repeated indefinitely; and, there-
fore, we cannot in this way come to a final principle.
And in the next place, most of those who use language,
even with great precision and consistency, would find
it difficult or impossible to give good definitions even
of a few of the general names which they use; and
therefore their practice cannot be regulated by any
H 2
100 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
11
tacit reference to such definitions. That definitions of
terms are of great use and importance in their right
place, we shall soon see; but their place is not to
regulate the use of common language.
What then, once more, is this regulative principle?
What rules do men follow in the use of words, so as
commonly to avoid confusion and ambiguity? How do
they come to understand each other so well as they
ordinarily do, respecting the limits of classes never
defined, and which they cannot define? What is the
common Convention, or Condition to which they con-
form?
6. Condition of the Use of Terms. To this we reply,
that the Condition which regulates the use of lan-
guage, is, that it shall be capable of being used;—that
is, that general assertions shall be possible. The term
tree is applicable as far as it is useful in expressing our
knowledge concerning trees :-thus we know that trees
are fixed in the ground, have a solid stem, branches,
leaves, and many other properties. With regard to
all the objects which surround us, we have an im-
mense store of knowledge of such properties, and we
employ the names of the objects in such a manner as
enables us to express these properties.
But the connexion of such properties is variable and
indefinite. Some properties are constantly combined,
others occasionally only. The leaves of different oaks
resemble each other, the branches resemble far less,
and may differ very widely. The term oak does not
enable us to say that all oaks have straight branches
or all crooked. Terms can only express properties as
far as they are constant. Not only, therefore, the
accumulation of a vast mass of knowledge of the pro-
perties and attributes of objects, but also an observa-
tion of the habitual connexion of such properties is
needed, to direct us to the consistent application of
terms:-to enable us to apply them so as to express
truths. But here again we are largely provided with
the requisite knowledge and observation by the com-
mon course of our existence. The unintermitting
stream of experience supplies us with an incalculable
THE IDEA OF LIKENESS.
ΙΟΙ
All men have
same form of
amount of such observed connexions.
observed that the associations of the
leaves are more constant than of the same form of
branches;—that though persons walk in different atti-
tudes, none go on all fours; and thus the term oak is
so applied as to include those cases in which the
leaves are alike in form though the branches be unlike;
and though we should refuse to apply the term man
to a class of creatures which habitually and without
compulsion used four legs, we make no scruple of affix-
ing it to persons of very different figures. The whole
of human experience being composed of such observed
connexions, we have thus materials even for the im-
mense multiplicity of names which human language
contains; all which names are, as we have said, regu-
lated in their application by the condition of their ex-
pressing such experience.
Thus amid the countless combinations of properties
and divisions of classes which the structure of lan-
guage implies, scarcely any are arbitrary or capricious.
A word which expressed a mere wanton collection of
unconnected attributes could hardly be called a word;
for of such a collection of properties no truth could be
asserted, and the word would disappear, for want of
some occasion on which it could be used. Though much
of the fabric of language appears, not unnaturally, fan-
tastical and purely conventional, it is in fact otherwise.
The associations and distinctions of phraseology are not
more fanciful than is requisite to make them corre-
spond to the apparent caprices of nature or of thought;
and though much in language may be called conven-
tional, the conventions exist for the sake of expressing
some truth or opinion, and not for their own sake.
The principle, that the condition of the use of terms is
the possibility of general, intelligible, consistent asser-
tions, is true in the most complete and extensive sense.
7. Terms may have different Uses.-The Terms
with which we are here most concerned are Names of
Classes of natural objects; and when we say that the
principle and the limit of such Names are their use in
expressing propositions concerning the classes, it is
102 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
clear that much will depend on the kind of proposi-
tions which we mainly have to express: and that the
same name may have different limits, according to the
purpose we have in view. For example, is the whale
properly included in the general term fish? When
men are concerned in catching marine animals, the
main features of the process are the same however the
animals may differ; hence whales are classed with
fishes, and we speak of the whale-fishery. But if we
look at the analogies of organization, we find that, ac-
cording to these, the whale is clearly not a fish, but a
beast, (confining this term, for the sake of distinctness,
to suckling beasts or mammals). In Natural History,
therefore, the whale is not included among fish. The
indefinite and miscellaneous propositions which lan-
guage is employed to enunciate in the course of com-
mon practical life, are replaced by a more coherent
and systematic collection of properties, when we come
to aim at scientific knowledge. But we shall hereafter
consider the principle of the classifications of Natural
History; our present subject is the application of the
Idea of Likeness in common practice and common lan-
guage.
8. Gradation of Kinds. Common names, then,
include many individuals associated in virtue of resem-
blances, and of permanently connected properties; and
such names are applicable as far as they serve to ex-
press such properties. These collections of individuals
are termed Kinds, Sorts, Classes.
But this association of particulars is capable of
degrees. As individuals by their resemblances form
Kinds, so kinds of things, though different, may resem-
ble each other so as to be again associated in a higher
Class; and there may be several successive steps of
such classification. Man, horse, tree, stone, are each a
name of a Kind; but animal includes the two first
and excludes the others; living thing is a term which
includes animal and tree but not stone; body includes
all the four. And such a subordination of kinds may
be traced very widely in the arrangements of lan-
guage.
THE IDEA OF LIKENESS.
103
The condition of the use of the wider is the same as
that of the narrower Names of Classes;-they are
good as far as they serve to express true propositions.
In common language, though such an order of gene-
rality may in a variety of instances be easily dis-
cerned, it is not systematically and extensively referred
to; but this subordination and graduated compre-
hensiveness is the essence of the methods and nomen-
clatures of Natural History, as we shall soon have to
show.
But such subordination is not without its use, even
in common cases, and when it is expressed in the
terms of common language. Thus organized body is a
term which includes plants and animals; animal in-
cludes beasts, birds, fishes; beast includes horses and
dogs; dogs, again, are greyhounds, spaniels, terriers.
9. Characters of Kinds.-Now when we have such
a Series of Names and Classes, we find that we take
for granted irresistibly that each class has some Cha-
racter which distinguishes it from other classes included
in the superior division. We ask what kind of beast
a dog is; what kind of animal a beast is; and we
assume that such questions admit of answer;—that
each kind has some mark or marks by which it may
be described. And such descriptions may be given :
an animal is an organized body having sensation and
volition; man is a reasonable animal. Whether or no
we assent to the exactness of these definitions, we
allow the propriety of their form. If we maintain
these definitions to be wrong, we must believe some
others to be right, however difficult it may be to hit
upon them. We entertain a conviction that there must
be, among things so classed and named, a possibility of
defining each.
Now what is the foundation of this postulate? What
is the ground of this assumption, that there must exist
a definition which we have never seen, and which per-
haps no one has seen in a satisfactory form? The
knowledge of this definition is by no means necessary
to our using the word with propriety; for any one can
make true assertions about dogs, but who can define a
:
104 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
dog? And yet if the definition be not necessary to
enable us to use the word, why is it necessary at all?
I allow that we possess an indestructible conviction
that there must be such a character of each kind as
will supply a definition; but I ask, on what this con-
viction rests.
I reply, that our persuasion that there must needs
be characteristic marks by which things can be de-
fined in words, is founded on the assumption of the
necessary possibility of reasoning.
The reference of any object or conception to its
class without definition, may give us a persuasion that
it shares the properties of its class, but such classing
does not enable us to reason upon those properties.
When we consider man as an animal, we ascribe to
him in thought the appetites, desires, affections, which
we habitually include in our notion of animal: but
except we have expressed these in some definition or
acknowledged description of the term animal, we can
make no use of the persuasion in ratiocination. But
if we have described animals as 'being impelled to
action by appetites and passions,' we can not only
think, but say, 'man is an animal, and therefore he
is impelled to act by appetites and passions.' And if
we add a further definition, that man is a reasonable
animal,' and if it appear that' reason implies con-
formity to a rule of action,' we can then further infer
that man's nature is to conform the results of animal
appetite and passion to a rule of action.
The possibility of pursuing any such train of reason-
ing as this, depends on the definitions, of animal and
of man, which we have introduced; and the possibility
of reasoning concerning the objects around us being
inevitably assumed by us from the constitution of our
nature, we assume consequently the possibility of such
definitions as may thus form part of our deduction,
and the existence of such defining characters.
10. Difficulty of Definitions.-But though men are,
on such grounds, led to make constant and importu-
nate demands for definitions of the terms which they
employ in their speculations, they are, in fact, far
THE IDEA OF LIKENESS.
105
from being able to carry into complete effect the pos-
tulate on which they proceed, that they must be able
to find definitions which by logical consequence shall
lead to the truths they seek. The postulate overlooks
the process by which our classes of things are formed
and our names applied. This process consisting, as
we have already said, in observing permanent con-
nexions of properties, and in fixing them by the at-
tribution of names, is of the nature of the process
of Induction, of which we shall afterwards have to
speak. And the postulate is so far true, that this
process of induction being once performed, its result
may usually be expressed by means of a few defi-
nitions, and may thus lead by a deduction to a train
of real truths.
But in the subjects where we principally find such a
subordination of classes as we have spoken of, this
process of deduction is rarely of much prominence: for
example, in the branches of natural history. Yet it is
in these subjects that the existence and importance of
these characteristic marks, which we have spoken of,
principally comes into view. In treating of these
marks, however, we enter upon methods which are
technical and scientific, not popular and common. And
before we make this transition, we have a remark to
make on the manner in which writers, without refer-
ence to physics or natural history, have spoken of
kinds, their subordination, and their marks.
II.
'The Five Words.'-These things,-the Nature
and Relations of Classes,—were, in fact, the subjects of
minute and technical treatment by the logicians of the
school of Aristotle. Porphyry wrote an Introduction
to the Categories of that philosopher, which is entitled
On the Five Words. The Five Words' are Genus,
Species, Difference, Property, Accident. Genus and
Species are superior and inferior classes, and are stated²
to be capable of repeated subordination. The most
6
6
2 Porphyr. Isagog. C. 23.
106 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
general Genus' is the widest class; the 'most special
Species' the narrowest. Between these are interme-
diate classes, which are Genera with regard to those
below, and Species with regard to those above them.
Thus Being is the most general Genus; under this is
Body; under Body is Living Body; under this again
Animal; under Animal is Rational Animal, or Man;
under Man are Socrates and Plato, and other indi-
vidual men.
The Difference is that which is added to the genus
to make the species; thus Rational is the Difference
by which the genus Animal is made the species Man
the Difference in this Technical sense is the 'Specific,'
or species-making Difference³. It forms the Defini-
tion for the purposes of logic, and corresponds to the
'Character' (specific or generic) of the Natural His-
torians. Indeed several of them, as, for instance, Lin-
næus, in his Philosophia Botanica, always call these
Characters the Difference, by a traditional application
of the Peripatetic terms of art.
Of the other two words, the Property is that which
though not employed in defining the class, belongs to
every part of it*: it is, 'What happens to all the
class, to it alone, and at all times; as to be capable of
laughing is a Property of man.'
The Accident is that which may be present and
absent without the destruction of the subject, as to
sleep is an Accident (a thing which happens) to man.
I need not dwell further on this system of techni-
calities. The most remarkable points in it are those
which I have already noticed; the doctrine of the
successive Subordination of genera, and the fixing
attention upon the Specific Difference. These doctrines,
though invented in order to make reasoning more sys-
tematic, and at a period anterior to the existence of
any Classificatory Science, have, by a curious contrast
with the intentions of their founders, been of scarcely
3 ειδοποιός.
4 Isagog. c. 4.
THE IDEA OF LIKENESS.
107
any use in sciences of Reasoning, but have been amply
applied and developed in the Natural History which
arose in later times.
We must now treat of the principles on which this
science (Natural History) proceeds, and explain what
peculiar and technical processes it employs in addition
to those of common thought and common language.
!
CHAPTER II.
THE METHODS OF NATURAL HISTORY, AS REGULATED
BY THE IDEA OF LIKENESS.
SECT. I.-Natural History in general.
I. Idea of Likeness in Natural History.-THE
various branches of Natural History, in so far as they
are classificatory sciences merely, and do not depend
upon physiological views, rest upon the same Idea of
Likeness which is the ground of the application of the
names, more or less general, of common language. But
the nature of science requires that, for her purposes,
this Idea should be applied in a more exact and rigour-
ous manner than in its common and popular employ-
ment; just as occurs with regard to the other Ideas
on which science is founded;—for instance, as the idea
of space gives rise, in popular use, to the relations
implied in the prepositions and adjectives which refer
to position and form, and in its scientific develop-
ment gives rise to the more precise relations of geo-
metry.
The way in which the Idea of Likeness has been
applied, so as to lead to the construction of a science,
is best seen in Botany: for, in the Classification of
Animals, we are inevitably guided by a consideration
of the function of parts; that is, by an idea of purpose,
and not of likeness merely and in Mineralogy, the
attempts at classification on the principles of Natural
History have been hitherto very imperfectly success-
ful. But in Botany we have an example of a branch
of knowledge in which systematic classification has
been effected with great beauty and advantage; and
in which the peculiarities and principles on which such
METHODS OF NATURAL HISTORY. 109
classification must depend have been carefully studied.
Many of the principal botanists, as Linnæus, Adanson,
Decandolle, have not only practically applied, but have
theoretically enunciated, what they held to be the
sound maxims of classificatory science: and have thus
enabled us to place before the reader with confidence
the philosophy of this kind of science.
2. Condition of its Use.-We may begin by remark-
ing that the Idea of Likeness, in its systematic employ-
ment, is governed by the same principle which we
have already spoken of as regulating the distribution
of things into kinds, and the assignment of names in
unsystematic thought and speech; namely, the condi-
tion that general propositions shall be possible. But as
in this case the propositions are to be of a scientific
form and exactness, the likeness must be treated with
a corresponding precision; and its consequences traced
by steady and distinct processes. Naturalists must,
for their purposes, employ the resemblances of objects
in a technical manner: This technical process may be
considered as consisting of three steps;-The fixation
of the resemblances; The use of them in making a
classification; The means of applying the classification.
These three steps may be spoken of as the Terminology,
the Plan of the System, and the Scheme of the Cha-
racters.
SECT. II.—Terminology¹.
3. Terminology signifies the collection of terms, or
technical words, which belong to the science. But in
fixing the meaning of the terms, at least of the de-
scriptive terms, we necessarily fix, at the same time,
the perceptions and notions which the terms are to
1 Decandolle and others use the
term Glossology instead of Termino-
logy, to avoid the blemish of a word
compounded of two parts taken from
different languages. The convenience
of treating the termination ology (and
a few other parts of compounds) as
not restricted to Greek combinations,
is so great, that I shall venture, in
these cases, to disregard this philo-
logical scruple.
IIO PHILOSOPHY OF CLASSIFICATORY SCIENCES.
convey; and thus the Terminology of a classificatory
science exhibits the elements of its substance as well
as of its language. A large but indispensable part of
the study of botany (and of mineralogy and zoology
also,) consists in the acquisition of the peculiar voca-
bulary of the science.
The meaning of technical terms can be fixed in the
first instance only by convention, and can be made
intelligible only by presenting to the senses that which
the terms are to signify. The knowledge of a colour
by its name can only be taught through the eye. No
description can convey to a hearer what we mean by
apple-green or French grey. It might, perhaps, be
supposed that, in the first example, the term apple,
referring to so familiar an object, sufficiently suggests
the colour intended. But it may easily be seen that
this is not true; for apples are of many different hues
of green, and it is only by a conventional selection that
we can appropriate the term to one special shade.
When this appropriation is once made, the term refers
to the sensation, and not to the parts of this term; for
these enter into the compound merely as a help to the
memory, whether the suggestion be a natural con-
nexion as in 'apple-green,' or a casual one as in
French grey.' In order to derive due advantage
from technical terms of this kind, they must be asso-
ciated immediately with the perception to which they
belong; and not connected with it through the vague
usages of common language. The memory must retain
the sensation; and the technical word must be under-
stood as directly as the most familiar word, and more
distinctly. When we find such terms as tin-white or
pinchbeck-brown, the metallic colour so denoted ought
to start up in our memory without delay or search.
This, which it is most important to recollect with
respect to the simpler properties of bodies, as colour
and form, is no less true with respect to more com-
pound notions. In all cases the term is fixed to a
peculiar meaning by convention; and the student, in
order to use the word, must be completely familiar
with the convention, so that he has no need to frame
METHODS OF NATURAL HISTORY.
III
Thus
conjectures from the word itself. Such conjectures
would always be insecure, and often erroneous.
the term papilionaceous, applied to a flower, is em-
ployed to indicate, not only a resemblance to a butter-
fly, but a resemblance arising from five petals of a
certain peculiar shape and arrangement; and even if
the resemblance to a butterfly were much stronger than
it is in such cases, yet if it were produced in a dif-
ferent way, as, for example, by one petal, or two only,
instead of a 'standard,' two wings,' and a 'keel'
consisting of two parts more or less united into one,
we should no longer be justified in speaking of it as a
'papilionaceous' flower.
6
The formation of an exact and extensive descriptive
language for botany has been executed with a degree
of skill and felicity, which, before it was attained,
could hardly have been dreamt of as attainable. Every
part of a plant has been named; and the form of every
part, even the most minute, has had a large assemblage
of descriptive terms appropriated to it, by means of
which the botanist can convey and receive knowledge
of form and structure, as exactly as if each minute
part were presented to him vastly magnified. This
acquisition was part of the Linnæan Reform, of which
we have spoken in the History. 'Tournefort,' says
Decandolle, appears to have been the first who really
perceived the utility of fixing the sense of terms in
such a way as always to employ the same word in the
same sense, and always to express the same idea by
the same word; but it was Linnæus who really created
and fixed this botanical language, and this is his fairest
claim to glory, for by this fixation of language he
has shed clearness and precision over all parts of the
science.'
It is not necessary here to give any detailed account
of the terms of botany. The fundamental ones have
been gradually introduced, as the parts of plants were
more carefully and minutely examined. Thus the
flower was successively distinguished into the calyx,
2 Theor. Elem. P. 327.
112 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
:
the corolla, the stamens, and the pistils: the sections
of the corolla were termed petals by Columna; those
of the calyx were called sepals by Necker³. Some-
times terms of greater generality were devised; as
perianth to include the calyx and corolla, whether one
or both of these were present*; pericarp for the part
inclosing the grain, of whatever kind it be, fruit, nut,
pod, &c. And it may easily be imagined that descrip-
tive terms may, by definition and combination, become
very numerous and distinct. Thus leaves may bẹ
called pinnatifid, pinnatipartite, pinnatisect, pinnati-
lobate, palmatifid, palmatipartite, &c., and each of these
words designates different combinations of the modes
and extent of the divisions of the leaf with the divi-
sions of its outline. In some cases arbitrary numerical
relations are introduced into the definition: thus a leaf
is called bilobate when it is divided into two parts by
a notch; but if the notch go to the middle of its
length, it is bifid; if it go near the base of the leaf, it
is bipartite; if to the base, it is bisect. Thus, too, a
pod of a cruciferous plant is a silica¹ if it be four
times as long as it is broad, but if it be shorter than
this it is a silicula. Such terms being established, the
form of the very complex leaf or frond of a fern is
exactly conveyed by the following phrase: fronds
rigid pinnate, pinnæ recurved subunilateral pinnatifid,
the segments linear undivided or bifid spinuloso-ser-
rate.
6
C
Other characters, as well as form, are conveyed with
the like precision: Colour by means of a classified
scale of colours, as we have seen in speaking of the
Measures of Secondary Qualities; to which, however,
we must add, that the naturalist employs arbitrary
names, (such as we have already quoted,) and not mere
numerical exponents, to indicate a certain number of
3 Decandolle, 329.
4 For this Erhart and Decandolle
use Perigone.
5 Dec. 318.
6 Ib. 493.
7 Tb. 422.
8 Hooker, Brit. Flo. p. 45. Hy-
menophyllum Wilsoni, Scottish filmy-
fern, abundant in the highlands of
Scotland and about Killarney.
METHODS OF NATURAL HISTORY. 113
selected colours. This was done with most precision
by Werner, and his scale of colours is still the most
usual standard of naturalists. Werner also introduced
a more exact terminology with regard to other characters
which are important in mineralogy, as lustre, hard-
ness. But Mohs improved upon this step by giving a
numerical scale of hardness, in which talc is 1, gypsum
2, calc spar 3, and so on, as we have already explained
in the History of Mineralogy. Some properties, as
specific gravity, by their definition give at once a
numerical measure; and others, as crystalline form,
require a very considerable array of mathematical cal-
culation and reasoning, to point out their relations and
gradations. In all cases the features of likeness in the
objects must be rightly apprehended, in order to their
being expressed by a distinct terminology. Thus no
terms could describe crystals for any purpose of natu-
ral history, till it was discovered that in a class of
minerals the proportion of the faces might vary, while
the angle remained the same. Nor could crystals be
described so as to distinguish species, till it was found
that the derived and primitive forms are connected by
very simple relations of space and number. The dis-
covery of the mode in which characters must be appre-
hended so that they may be considered as fixed for a
class, is an important step in the progress of each
branch of Natural History; and hence we have had,
in the History of Mineralogy and Botany, to distin-
guish as important and eminent persons those who
made such discoveries, Romé de Lisle and Haiy,
Cesalpinus and Gesner.
•
By the continued progress of that knowledge of
minerals, plants, and other natural objects, in which
such persons made the most distinct and marked steps,
but which has been constantly advancing in a more
gradual and imperceptible manner, the most important
and essential features of similarity and dissimilarity in
such objects have been selected, arranged, and fitted
with names; and we have thus in such departments,
systems of Terminology which fix our attention upon
the resemblances which it is proper to consider, and
VOL. II.
I
114 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
:
enable us to convey them in words. We have now to
speak of the mode in which such resmblances have
been employed in the construction of a Systematic
Classification.
SECT. III. The Plan of the System.
4. The collection of sound views and maxims by
which the resemblances of natural objects are applied
so as to form a scientific classification, is a department
of the philosophy of natural history which has been
termed by some writers (as Decandolle), Taxonomy, as
containing the Laws of the Taxis (arrangement).
By some Germans this has been denominated Sys-
tematik; if we could now form a new substantive after
the analogy of the words Logick, Rhetorick, and the
like, we might call it Systematick. But though our
English writers commonly use the expression Sys-
tematical Botany for the Botany of Classification, they
appear to prefer the term Diataxis for the method of
constructing the classification. The rules of such a
branch of science are curious and instructive.
In framing a Classification of objects we must attend
to their resemblances and differences. But here the
question occurs, to what resemblances and differences?
for a different selection of the points of resemblance
would give different results: a plant frequently agrees
in leaves with one group of plants, in flowers with an-
other. Which set of characters are we to take as our
guide?
The view already given of the regulative principle
of all classification, namely, that it must enable us to
assert true and general propositions, will obviously
occur as applicable here. The object of a scientific
Classification is to enable us to enunciate scientific
truths we must therefore classify according to those
resemblances of objects (plants or any others) which
bring to light such truths.
But this reply to the inquiry, 'On what characters
of resemblance we are to found our system,' is still too
general and vague to be satisfactory. It carries us,
METHODS OF NATURAL HISTORY.
115
however, as far as this;—that since the truths we are
to attend to are scientific truths, governed by precise
and homogeneous relations, we must not found our
scientific Classification on casual, indefinite, and uncon-
nected considerations. We must not, for instance, be
satisfied with dividing plants, as Dioscorides does, into
aromatic, esculent, medicinal and vinous; or even with
the long prevalent distribution into trees, shrubs, and
herbs; since in these subdivisions there is no consistent
principle.
5. Latent Reference to Natural Affinity.—But there
may be several kinds of truths, all exact and coherent,
which may be discovered concerning plants or any
other natural objects; and if this should be the case,
our rule leaves us still at a loss in what manner our
classification is to be constructed. And, historically
speaking, a much more serious inconvenience has been
this;-that the task of classification of plants was ne-
cessarily performed when the general laws of their
form and nature were very little known; or rather,
when the existence of such laws was only just begin-
ning to be discerned. Even up to the present day,
the general propositions which botanists are able to
assert concerning the structure and properties of plants,
are extremely imperfect and obscure.
We are thus led to this conclusion:-that the Idea
of Likeness could not be applied so as to give rise to a
scientific Classification of plants, till considerable pro-
gress was made in studying the general relations of
vegetable form and life; and that the selection of the
resemblances which should be taken into account,
must depend upon the nature of the relations which
were then brought into view.
ness.
But this amounts to saying that, in the considera-
tion of the Classification of vegetables, other Ideas
must be called into action as well as the Idea of Like-
The additional general views to which the
more intimate study of plants leads, must depend,
like all general truths, upon some regulating Idea
which gives unity to scattered facts. No progress
could be made in botanical knowledge without the
I 2
116 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
operation of such principles: and such additional Ideas
must be employed, besides those of mere likeness and
unlikeness, in order to point out that Classification
which has a real scientific value.
Accordingly, in the classificatory sciences, Ideas
other than Likeness do make their appearance.
Such
Ideas in botany have influenced the progress of the
science, even before they have been clearly brought
into view. We have especially the Idea of Affinity,
which is the basis of all Natural Systems of Classi-
fication, and which we shall consider in a succeeding
chapter. The assumption that there is a Natural Sys-
tem, an assumption made by all philosophical botanists,
implies a belief in the existence of Natural Affinity,
and is carried into effect by means of principles which
are involved in that Idea. But as the formation of all
systems of classification must involve, in a great de-
gree, the Idea of Resemblance and Difference, I shall
first consider the effect of that Idea, before I treat
specially of Natural Affinity.
6. Natural Classes. Many attempts were made to
classify vegetables before the rules which govern a
natural system were clearly apprehended. Botanists
agree in esteeming some characters as of more value
than others, before they had agreed upon any general
rules or principles for estimating the relative import-
ance of the characters. They were convinced of the
necessity of adding other considerations to that of Re-
semblance, without seeing clearly what these others
ought to be. They aimed at a Natural Classification,
without knowing distinctly in what manner it was to
be Natural.
The attempts to form Natural Classes, therefore,
in the first part of their history, belong to the Idea
of Likeness, though obscurely modified, even from an
early period, by the Ideas of Affinity, and even of
Function and of Development. Hence Natural
Classes may, to a certain extent, be treated of in this
place.
Natural Classes are opposed to Artificial Classes
which are understood to be regulated by an assumed
METHODS OF NATURAL HISTORY. 117
character. Yet no classes can be so absolutely Arti-
ficial in this sense, as to be framed upon characters
arbitrarily assumed; for instance, no one would speak
of a class of shrubs defined by the circumstance of
each having a hundred leaves: for of such a class no
assertion could be made, and therefore the class could
never come under our notice. In what sense then are
Artificial Classes to be understood, as opposed to Na-
tural?
7. Artificial Classes.-To this question, the follow-
ing is the answer. When Natural Classes of a certain
small extent have been formed, a system may be
devised which shall be regulated by a few selected cha-
racters, and which shall not dissever these small Natu-
ral Classes, but conform to them as far as they go. If
these selected characters be then made absolute and
imperative, and if we abandon all attempt to obtain
Natural Classes of any higher order and wider extent,
we form an Artificial System.
Thus in the Linnæan System of Botanical Classifica-
tion, it is assumed that certain natural groups, namely,
Species and Genera, are established; it is conceived,
moreover, that the division of Classes according to
the number of stamens and of pistils does not violate
the natural connexions of Species and Genera. This
arrangement, according to the number of stamens and
pistils, (further modified in certain cases by other con-
siderations,) is then made the ground of all the higher
divisions of plants, and thus we have an Artificial
System.
It has been objected to this view, that the Linnæan
Artificial System does not in all cases respect the
boundaries of genera, but would, if rigorously applied,
distribute the species of the same genus into different
artificial classes; it would divide, for instance, the
genera Valeriana, Geranium, &c. To this we must
reply, that so far as the Linnæan System does this, it
is an imperfect Artificial System. Its great merit is
in its making such a disjunction in comparatively so
• Decand. Theor. Elem. p. 45.
118 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
few cases; and in the artificial characters being, for
the most part, obvious and easily applied.
8. Are Genera Natural?—It has been objected also
that Genera are not Natural groups. Linnæus asserts
in the most positive manner that they are¹. On which
Adanson observes", 'I know not how any Botanist can
maintain such a thesis: that which is certain is, that
up to the present time no one has been able to prove
it, nor to give an exact definition of a natural genus,
but only of an artificial.' He then brings several
arguments to confirm this view.
But we are to observe, in answer to this, that
Adanson improperly confounds the recognition of the
existence of a natural group with the invention of a
technical mark or definition of it.
Genera are groups
of species associated in virtue of natural affinity, of
general resemblance, of real propinquity: of such
groups, certain selected characters, one or few, may
usually be discovered, by which the species may be
referred to their groups. These Artificial characters
do not constitute, but indicate the genus: they are the
Diagnosis, not the basis of the Diataxis: and they are
always subject to be rejected, and to have others sub-
stituted for them, when they violate the natural con-
nexion of species which a minute and enlarged study
discovers.
It is, therefore, no proof that Genera are not Natu-
ral, to say that their artificial characters are different
in different systems. Such characters are only different
attempts to confine the variety of nature within the
limits of definition. Nor is it sufficient to say that
these groups themselves are different in different wri-
ters; that some botanists make genera what others
make only species; as Pedicularis, Rhinanthus, Eu-
phrasia, Antirrhinum 13. This discrepancy shows only
that the natural arrangement is not yet completely
known, even in the smaller groups; a conclusion to
which we need not refuse our assent. But in opposi-
10 Phil. Bot. Art. 165.
•
11 Famille de Ph. Pref. cv.
12 Adanson, p. cvi
METHODS OF NATURAL HISTORY.
119
..
tion to these negatives, the manner in which Genera
have been established proves that they are regulated
by the principle of being natural, and by that alone.
For they are not formed according to any à priori
rule. The Botanist does not take any selected or
arbitrary part or parts of the plants, and marshal his
genera according to the differences of this part. On
the contrary, the divisions of genera are sometimes
made by means of the flower; sometimes by means of
the fruit: the anthers, the stamens, the seeds, the
pericarp, and the most varied features of these parts,
are used in the most miscellaneous and unsystematic
manner. Linnæus has indeed laid down a maxim that
the characteristic differences of genera must reside in
the fructification 13: but Adanson has justly remarked ¹,
that an arbitrary restriction like this makes the groups
artificial: and that in some families other characters
are more essential than those of the fructification; as
the leaves in the families of Aparinece and Leguminosae,
and the disposition of the flowers in Labiatæ. And
Naturalists are so far from thinking it sufficient to
distribute species into genera by arbitrary marks, that
we find them in many cases lamenting the absence of
good natural marks: as in the families of Umbelliferæ,
where Linnæus declared that any one who could find
good characters of genera would deserve great admira-
tion, and where it is only of late that good characters
have been discovered and the arrangement settled 15 by
means principally of the ribs of the fruit ¹º.
It is thus clear that Genera are not established on
any assumed or preconceived basis. What, then, is
the principle which regulates botanists when they try
to fix genera? What is the arrangement which they
thus wish for, without being able to hit upon it?
What is the tendency which thus drives them from
the corolla to the anthers, from the flower to the fruit,
13 Phil. Bot. Art. 152.
15 Lindley, Nat. Syst. p. 5.
14 Adanson, Pref. p. cxx.
16 In like manner we find Cuvier saying of Rondelet that he has 'un sen-
timent très vrai des genres.' Hist. Ichth. p. 39
120 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
from the fructification to the leaves? It is plain that
they seek something, not of their own devising and
creating;—not anything merely conventional and sys-
tematic; but something which they conceive to exist
in the relations of the plants themselves; something
which is without the mind, not within;-in nature,
not in art;-in short, a Natural Order.
Thus the regulative principle of a Genus, or of any
other natural group is, that it is, or is supposed to be,
natural. And by reference to this principle as our
guide, we shall be able to understand the meaning of
that indefiniteness and indecision which we frequently
find in the descriptions of such groups, and which
must appear so strange and inconsistent to any one
who does not suppose these descriptions to assume any
deeper ground of connexion than an arbitrary choice.
of the botanist. Thus in the family of the Rose-tree,
we are told that the ovules are very rarely erect¹, the
stigmata are usually simple. Of what use, it might
be asked, can such loose accounts be? To which the
answer is, that they are not inserted in order to dis-
tinguish the species, but in order to describe the family,
and the total relations of the ovules and of the stig-
mata of the family are better known by this general
statement. A similar observation may be made with
regard to the Anomalies of each group, which occur so
commonly, that Mr. Lindley, in his Introduction to the
Natural System of Botany, makes the 'Anomalies' an
article in each Family. Thus, part of the character of
the Rosacea is that they have alternate stipulate leaves,
and that the albumen is obliterated: but yet in Lowea,
one of the genera of this family, the stipulæ are absent;
and the albumen is present in another, Neillia. This
implies, as we have already seen, that the artificial
character (or diagnosis as Mr. Lindley calls it) is im-
perfect. It is, though very nearly, yet not exactly,
commensurate with the natural group: and hence, in
certain cases, this character is made to yield to the
general weight of natural affinities.
17 Lindley, Nat. Syst. p. 81.
METHODS OF NATURAL HISTORY.
121
9. Difference of Natural History and Mathematics.
These views,—of classes determined by characters
which cannot be expressed in words,-of propositions
which state, not what happens in all cases, but only
usually,—of particulars which are included in a class
though they transgress the definition of it, may very
probably surprise the reader. They are so contrary to
many of the received opinions respecting the use of
definitions and the nature of scientific propositions,
that they will probably appear to many persons highly
illogical and unphilosophical. But a disposition to
such a judgment arises in a great measure from this;
-that the mathematical and mathematico-physical
sciences have, in a great degree, determined men's
views of the general nature and form of scientific truth;
while Natural History has not yet had time or oppor-
tunity to exert its due influence upon the current
habits of philosophizing. The apparent indefiniteness
and inconsistency of the classifications and definitions
of Natural History belongs, in a far higher degree, to
all other except mathematical speculations: and the
modes in which approximations to exact distinctions
and general truths have been made in Natural His-
tory, may be worthy our attention, even for the light
they throw upon the best modes of pursuing truth of
all kinds.
10. Natural Groups given by Type not by Definition.
-The further development of this suggestion must
be considered hereafter. But we may here observe,
that though in a Natural Group of objects a definition
can no longer be of any use as a regulative principle,
classes are not, therefore, left quite loose, without any
certain standard or guide. The class is steadily fixed,
though not precisely limited; it is given, though not
circumscribed; it is determined, not by a boundary
line without, but by a central point within; not by
what it strictly excludes, but by what it eminently
includes; by an example, not by a precept; in short,
instead of Definition we have a Type for our director.
A Type is an example of any class, for instance, a
species of a genus, which is considered as eminently
122 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
possessing the characters of the class. All the species.
which have a greater affinity with this Type-species
than with any others, form the genus, and are ranged
about it, deviating from it in various directions and
different degrees. Thus a genus may consist of several
species, which approach very near the type, and of
which the claim to a place with it is obvious; while
there may be other species which straggle further from
this central knot, and which yet are clearly more con-
nected with it than with any other. And even if
there should be some species of which the place is
dubious, and which appear to be equally bound by two
generic types, it is easily seen that this would not
destroy the reality of the generic groups, any more
than the scattered trees of the intervening plain pre-
vent our speaking intelligibly of the distinct forests of
two separate hills.
The Type-species of every genus, the Type-genus of
every family, is, then, one which possesses all the cha-
racters and properties of the genus in a marked and
prominent manner. The Type of the Rose family has
alternate stipulate leaves, wants the albumen, has the
ovules not erect, has the stigmata simple, and besides
these features, which distinguish it from the exceptions
or varieties of its class, it has the features which
make it prominent in its class. It is one of those
which possess clearly several leading attributes; and
thus, though we cannot say of any one genus that it
must be the Type of the family, or of any one species
that it must be the Type of the genus, we are still not
wholly to seek: the Type must be connected by
many affinities with most of the others of its group; it
must be near the center of the crowd, and not one of
the stragglers.
II. It has already been repeatedly stated, as the
great rule of all classification, that the classification
must serve to assert general propositions. It may be
asked what propositions we are able to enunciate by
means of such classifications as we are now treating of.
And the answer is, that the collected knowledge of the
characters, habits, properties, organization, and func-
METHODS OF NATURAL HISTORY.
123
tions of these groups and families, as it is found in the
best botanical works, and as it exists in the minds of
the best botanists, exhibits to us the propositions which
constitute the science, and to the expression of which
the classification is to serve. All that is not strictly
definition, that is, all that is not artificial character,
in the descriptions of such classes, is a statement of
truths, more or less general, more or less precise, but
making up, together, the positive knowledge which
constitutes the science. As we have said, the con-
sideration of the properties of plants in order to form
a system of classification, has been termed Taxonomy,
or the Systematick of Botany; all the parts of the
descriptions, which, taking the system for granted,
convey additional information, are termed the Phy-
siography of the science; and the same terms may be
applied in the other branches of Natural History.
12. Artificial and Natural Systems.—If I have suc-
ceeded in making it apparent that an artificial system
of characters necessarily implies natural classes which
are not severed by the artificial marks, we shall now
be able to compare the nature and objects of the Arti-
ficial and Natural Systems; points on which much has
been written in recent times.
The Artificial System is one which is, or professes
to be, entirely founded upon marks selected according
to the condition which has been stated, of not violating
certain narrow natural groups; namely in the Lin-
næan system, the natural genera of plants. The marks
which form the basis of the system, being thus selected,
are applied rigorously and universally without any
further regard to any other characters or indications of
affinity. Thus in the Linnæan system, which depends
mainly on the number of male organs or stamens,
and on the number of female organs or styles, the
largest divisions, or the Classes, are arranged according
to the number of the stamens, and are monandria,
diandria, triandria, tetrandria, pentandria, hexandria,
and so on: the names being formed of the Greek nu-
merical words, and of the word which implies male.
And the Orders of each of these Classes are distin-
124 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
guished by the number of styles, and are called mono-
gynia, digynia, trigynia, and so on, the termination of
these words meaning female. And so far as this nume-
rical division and subdivision go on, the system is a
rigorous system, and strictly artificial.
But the condition that the artificial system shall leave
certain natural affinities untouched, makes it impossible
to go through the vegetable kingdom by a method of
mere numeration of stamens and styles. The distinction
of flowers with twenty and with thirty stamens is not a
fixed distinction: flowers of one and the same kind, as
roses, have, some fewer than the former, some more
than the latter number. The Artificial System, there-
fore, must be modified. And there are various rela-
tions of connexion and proportion among the stamina
which are more permanent and important than their
mere number. Thus flowers with two longer and two
shorter stamens are not placed in the class tetrandria,
but are made a separate class didynamia; those with
four longer and two shorter are in like manner tetra-
dynamia, not hexandria; those in wich the filaments
are bound into two bundles are diadelphia. All these
and other classes are deviations from the plan of the
earlier Classes, and are so far defects of the artificial
system; but they are deviations requisite in order that
the system may leave a basis of natural groups, with-
out which it would not be a System of Vegetables.
And as the division is still founded on some properties
of the stamens, it combines not ill with that part of
the system which depends on the number of them.
The Classes framed in virtue of these various considera-
tions make up an Artificial System which is tolerably
coherent.
'But since the Artificial System thus regards natu-
ral groups, in what does it differ from a Natural Sys-
tem?' It differs in this:-That though it allows cer-
tain subordinate natural groups, it merely allows these,
and does not endeavour to ascend to any wider
natural groups. It takes all the higher divisions of its
scheme from its artificial characters, its stamens and
pistils, without looking to any natural affinities. It
METHODS OF NATURAL HISTORY.
125
accepts natural Genera, but it does not seek natural
Families, or Orders, or Classes. It assumes natural
groups, but does not investigate any; it forms wider
and higher groups, but professes to frame them arbi-
trarily.
But then, on the other hand, the question occurs,
'This being the case, what can be the use of the Arti-
ficial System? If its characters, in the higher stages
of classification, be arbitrary, how can it lead us to the
natural relations of plants? And the answer is, that
it does so in virtue of the original condition, that
there shall be certain natural relations which the arti-
ficial system shall not transgress; and that its use
arises from the facility with which we can follow the
artificial arrangement as far as it goes. We can count
the stamens and pistils, and thus we know the Class
and Order of our plant; and we have then to discover
its Genus and Species by means less symmetrical but
more natural. The Artificial System, though arbi-
trary in a certain degree, brings us to a Class in which
the whole of each Genus is contained, and there we
can find the proper Genus by a suitable method of
seeking. No Artificial System can conduct us into
the extreme of detail, but it can place us in a situation
where the detail is within our reach. We cannot find
the house of a foreign friend by its latitude and longi-
tude; but we may be enabled, by a knowledge of the
latitude and longitude, to find the city in which he
dwells, or at least the island; and we then can reach
his abode by following the road or exploring the
locality. The Artificial System is such a method of
travelling by latitude and longitude; the Natural
System is that which is guided by a knowledge of the
country.
The Natural System, then, is that which endeavours
to arrange by the natural affinities of objects; and
more especially, which attempts to ascend from the
lower natural groups to the higher; as for example
from genera to natural families, orders, and classes.
But as we have already hinted, these expressions of
natural affinities, natural groups, and the like, when
*:
126 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
considered in reference to the idea of resemblance
alone, without studying analogy or function, are very
vague and obscure. We must notice some of the
attempts which were made under the operation of this
imperfect view of the subject.
SECT. IV.-Modes of framing Natural Systems.
13. Decandolle 18 distinguishes the attempts at Na-
tural Classifications into three sorts: those of blind
trial (tâtonnement), those of general comparison, and
those of subordination of characters. The two former
do not depend distinctly upon any principle, except
resemblance; the third refers us to other views, and
must be considered in a future chapter.
Method of Blind Trial.-The notion of the exist-
ence of natural classes dependent on the general re-
semblance of plants,—of an affinity showing itself in
different parts and various ways, though necessarily
somewhat vague and obscure, was acted upon at an
early period, as we have seen in the formation of
genera; and was enunciated in general terms soon
after. Thus Magnolius¹ says that he discerns in plants
an affinity, by means of which they may be arranged
in families: 'Yet it is impossible to obtain from the
fructification alone the Characters of these families;
and I have therefore chosen those parts of plants in
which the principal characteristic marks are found, as
the root, the stem, the flower, the seed. In some
plants there is even a certain resemblance; an affinity
which does not consist in the parts considered sepa-
rately, but in their totality; an affinity which may be
felt but not expressed; as we see in the families of
agrimonies and cinquefoils, which every botanist will
judge to be related, though they differ by their roots,
their leaves, their flowers, and their seeds.'
18 Theor. Elem. art. 41.
19 Dec. Theor. Elem. art. 42. Petri Magnoli, Prodromus Hist. Gen. Plant.
1689.
METHODS OF NATURAL HISTORY.
127
This obscure feeling of a resemblance on the whole,
an affinity of an indefinite kind, appears fifty years
later in Linnæus's attempts. 'In the Natural Clas-
sification,' he says 20, 'no à priori rule can be admitted,
no part of the fructification can be taken exclusively
into consideration; but only the simple symmetry of
all its parts.' Hence though he proposed Natural
Families, and even stated the formation of such Fami-
lies to be the first and last object of all Methods, he
never gave the Characters of those groups, or con-
nected them by any method. He even declared it to
be impossible to lay down such a system of characters.
This persuasion was the result of his having refused to
admit into his mind any Idea more profound than that
notion of Resemblance of which he had made so much
and such successful use; he would not attempt to un-
ravel the Ideas of Symmetry and of Function on which
the clear establishment of natural relations must de-
pend. He even despised the study of the inner organ-
ization of plants; and reckoned" the Anatomici, who
studied the anatomy and physiology of plants and the
laws of vegetation, among the Botanophili, the mere
amateurs of his science.
The same notion of general resemblance and affinity,
accompanied with the same vagueness, is to be found
in the writer who least participated in the general
admiration of Linnæus, Buffon. Though it was in a
great measure his love of higher views which made
him dislike what he considered the pedantry of the
Swedish school, he does not seem to have obtained a
clearer sight of the principle of the natural method
than his rival, except that he did not restrict his
Characters to the fructification. Things must be ar-
ranged by their resemblances and differences, (he says
in 175022,) but the resemblances and differences must
be taken not from one part but from the whole; and
we must attend to the form, the size, the habit, the
number and position of the parts, even the substance
20 Dec. Theor. Elem. art. 42.
12 Phil. Bot. s. 44.
22 Adanson, p. clvi. Buffon, Hist. Nat. t. i. p. 21.
128 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
of the part; and we must make use of these elements
in greater or smaller number, as we have need.'
14. Method of General Comparison.—A country-
man of Buffon, who shared with him his depreciating
estimate of the Linnæan system, and his wish to found
a natural system upon a broader basis, was Adanson;
and he invented an ingenious method of apparently
avoiding the vagueness of the practice of following the
general feeling of resemblance. This method consisted
in making many Artificial Systems, in each of which
plants were arranged by some one part; and then col-
lecting those plants which came near each other in the
greatest number of those Artificial Systems, as plants
naturally the most related. Adanson gives an account²
of the manner in which this system arose in his mind.
He had gone to Senegal, animated by an intense zeal
for natural history; and there, amid the luxuriant
vegetation of the torrid zone, he found that the methods
of Linnæus and Tournefort failed him altogether as
means of arranging his new botanical treasures. He
was driven to seek a new system.
For this purpose,'
he says, 'I examined plants in all their parts, without
omitting any, from the roots to the embryo, the folding
of the leaves in the bud, their mode of sheathing 24, the
situation and folding of the embryo and of its radicle
in the seed, relatively to the fruit; in short, a number
of particulars which few botanists notice. I made in
the first place a complete description of each plant,
putting each of its parts in separate articles, in all its
details; when new species occurred I put down the
points in which they differed, omitting those in which
they agreed. By means of the aggregate of these com-
parative descriptions, I perceived that plants arranged
themselves into classes or families which could not be
artificial or arbitrary, not being founded upon one or
two parts, which might change at certain limits, but
on all the parts; so that the disproportion of one of
these parts was corrected and balanced by the intro-
duction of another.' Thus the principle of Resemblance
23 Pref. p. clvii.
24 ‘Leur manière de s'engainer.'
METHODS OF NATURAL HISTORY. 129
was to suffice for the general arrangement, not by
means of a new principle, as Symmetry or Organiza-
tion, which should regulate its application, but by a
numeration of the peculiarities in which the resem-
blance consisted.
The labour which Adanson underwent in the execu-
tion of this thought was immense. By taking each
Organ, and considering its situation, figure, number,
&c., he framed sixty-five Artificial Systems; and col-
lected his Natural Families by a numerical combina-
tion of these. For example, his sixty-fifth Artificial
System 25 is that which depends upon the situation of
the Ovary with regard to the Flower; according to
this system he frames ten Artificial Classes, including
ninety-three Sections: and of these Sections the result-
ing Natural Arrangement retains thirty-five, above
one-third the same estimate is applied in other cases.
But this attempt to make Number supply the de-
fects which the vague notion of Resemblance intro-
duces, however ingenious, must end in failure. For,
as Decandolle observes 26, it supposes that we know,
not only all the Organs of plants, but all the points of
view in which it is possible to consider them; and
even if this assumption were true, which it is not, and
must long be very far from being, the principle is
altogether vicious; for it supposes that all these points
of view, and all the resulting artificial systems are of
equal importance-a supposition manifestly erroneous.
We are thus led back to the consideration of the Rela-
tive Importance of Organs and their qualities, as a
basis for the classification of plants, which no Artificial
Method can supersede; and thus we find the necessity
of attending to something besides mere external and
detached Resemblance. The method of General Com-
parison cannot, any more than the method of Blind
Trial, lead us, with any certainty or clearness, to the
Natural Method. Adanson's Families are held by
the best botanists to be, for the greater part, Natural;
but his hypotheses are unfounded; and his success is
25 Adanson, Pref. p. cccxii.
VOL. II.
26 Dec. Theor. Elem. p. 67.
K
130 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
probably more due to the dim feeling of Affinity, by
which he was unconsciously guided, than to the help
he derived from his numerical processes.
In a succeeding chapter I shall treat of that Natu-
ral Affinity on which a Natural System must really be
founded. But before proceeding to this higher sub-
ject, we must say a few words on some of the other
parts of the philosophy of Natural History,-the Gra-
dation of Groups, the Nomenclature, the Diagnosis,
and the application of the methods to other subjects.
SECT. V.-Gradation of Groups.
15. It has been already noticed (last chapter,) that
even that vague application of the idea of resemblance
which gives rise to the terms of common language, in-
troduces a subordination of classes, as man, animal,
body, substance. Such a subordination appears in a
more precise form when we employ this idea in a
scientific manner as we do in Natural History. We
have then a series of divisions, each inclusive of the
lower ones, which are expressed by various metaphors
in different writers. Thus some have gone as far as
eight terms of the series 27, and have taken, for the
most part, military names for them; as Hosts, Legions,
Phalanxes, Centuries, Cohorts, Sections, Genera, Spe-
cies. But the most received series is Classes, Orders,
Genera, and Species; in which, however, we often have
other terms interpolated, as Sub-genera, or Sections of
genera. The expressions Family and Tribe, are com-
monly appropriated to natural groups; and we speak
of the Vegetable, Animal, Mineral Kingdom; but the
other metaphors of Provinces, Districts, &c., which
this suggests, have not been commonly used 28.
It will of course be understood that each ascending
step of classification is deduced by the same process
from the one below. A Genus is a collection of Spe-
cies which resemble each other more than they resem-
27 Adanson, p. cvi.
28 Sub-Kingdom has recently been employed by some naturalists.
METHODS OF NATURAL HISTORY.
131
ble other species; an Order is a collection of Genera
having, in like manner, the first degree of resemblance,
and so on. How close or how wide the Degrees of
Resemblance are, must depend upon the nature of the
objects compared, and cannot possibly be prescribed
beforehand. Hence the same term, Class and Order
for instance, may imply, in different provinces of
nature, very different degrees of resemblance. The
Classes of Animals are Insects, Birds, Fish, Beasts,
&c. The Orders of Beasts are Ruminants, Tardi-
grades, Plantigrades, &c. The two Classes of Plants
(according to the Natural Order") are Vascular and
Cellular, the latter having neither sexes, flowers, nor
spiral vessels.
The Vascular Plants are divided into
Orders, as Umbelliferæ, Ranunculaceæ, &c.; but be-
tween this Class and its Orders are interposed two
other steps:-two Sub-classes, Dicotyledonous and Mo-
nocotyledonous, and two Tribes of each: Angiospermia,
Gymnospermia of the first; and Petaloidece, Glumacic
of the second. Such interpolations are modifications
of the general formula of subordination, for the purpose
of accommodating it to the most prominent natural
affinities.
16. Species. As we have already seen in tracing
the principles of the Natural Method, when by the
intimate study of plants we seek to give fixity and
definiteness to the notion of resemblance and affinity
on which all these divisions depend, we are led to the
study of Organization and Analogy. But we make a
reference to physiological conditions even from the
first, with regard to the lowest step of our arrange-
ment, the Species; for we consider it a proof of the
impropriety of separating two Species, if it be shown
that they can by any course of propagation, culture,
and treatment, the one pass into the other. It is in
this way, for example, that it has been supposed to be
established that the common Primrose, Oxlip, Poly-
anthus, and Cowslip, are all the same species. Plants
which thus, in virtue of external circumstances, as soil,
29 Lindley.
K 2
132 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
exposure, climate, exhibit differences which may dis-
appear by changing the circumstances, are called Va-
rieties of the species. And thus we cannot say that a
Species is a collection of individuals which possess the
First Degree of Resemblance; for it is clear that a
primrose resembles another primrose more than it does
a cowslip; but this resemblance only constitutes a
Variety. And we find that we must necessarily in-
clude in our conception of Species, the notion of pro-
pagation from the same stock. And thus a Species
has been well defined 30: The collection of the indi-
viduals descended from one another, or from common
parents, and of those which resemble these as much as
these resemble each other.' And thus the sexual doctrine
of plants, or rather the consideration of them as things
which propagate their kind, (whether by seed, shoot, or
in any other way,) is at the basis of our classifications.
17. The First permanent Degree of Resemblance
among organized beings is thus that which depends on
this relation of generation, and we might expect that
the groups which are connected by this relation would
derive their names from the notion of generation. It
is curious that both in Greek and Latin languages and
in our own, the words which have this origin (yévos,
genus, kind,) do not, in the phraseology of science at
least, denote the nearest degree of relationship, but
have other terms subordinate to them, which appear
etymologically to indicate a mere resemblance of ap-
pearance (eldos, species, sort); and these latter terms
are appropriated to the groups resulting from propaga-
tion. Probably the reason of this is, that the former
terms (genus, &c.) had been applied so widely and
loosely before the scientific fixation of terms, that to
confine them to what we call species would have been
to restrict them in a manner too unusual to be con-
venient.
18. Varieties. Races.-The Species, as we have
said, is the collection of individuals which resemble
each other as much as do the offspring of a common
30 Cuv. Règne Animal, p. 19.
METHODS OF NATURAL HISTORY.
133
stock. But within the limits of this boundary, there
are often observable differences permanent enough to
attract our notice, though capable of being obliterated
by mixture in the course of generation. Such different
groups are called Varieties. Thus the Primrose and
Cowslip, as has been stated above, are found to be
varieties of the same plant; the Poodle and the Grey-
hound are well marked varieties of the species dog.
Such differences are hereditary, and it may be long
doubtful whether such hereditary differences are varie-
ties only, or different species. In such cases the term
Race has been applied.
SECT. VI.-Nomenclature.
19. The Nomenclature of any branch of Natural
History is the collection of names of all its species;
which, when they become extremely numerous, requires
some artifice to make it possible to recollect or apply
them. The known species of plants, for example, were
10,000 at the time of Linnæus, and are now probably
60,000. It would be useless to endeavour to frame
and employ separate names for each of these species.
The division of the objects into a subordinated sys-
tem of classification enables us to introduce a Nomen-
clature which does not require this enormous number
of names. The artifice employed to avoid this incon-
venience is to name a Species by means of two (or it
might be more) steps of the successive division. Thus
in Botany, each of the genera has its name, and the
species are marked by the addition of some epithet to
the name of the genus. In this manner about 1,700
generic names, with a moderate number of specific
names, were found by Linnæus sufficient to designate
with precision all the species of vegetables known at
his time. And this Binary Method of Nomenclature
has been found so convenient that it has been univer-
sally adopted in every other department of the Natural
History of organized beings.
Many other modes of Nomenclature have been tried,
but no other has at all taken root. Linnæus himself
134 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
appears at first to have intended marking each species
by the Generic Name accompanied by a characteristic
Descriptive Phrase; and to have proposed the employ-
ment of a trivial Specific Name, as he termed it, only
as a method of occasional convenience. The use of
these trivial names, has, however, become universal, as
we have said, and is by many persons considered the
greatest improvement introduced at the Linnæan re-
form.
Both Linnæus and other writers (as Adanson) have
given many maxims with a view of regulating the
selection of generic and specific names. The maxims
of Linnæus were intended as much as possible to ex-
clude barbarism and confusion, and have, upon the
whole, been generally adopted; though many of them
were objected to by his contemporaries (Adanson and
others), as capricious or unnecessary innovations.
Many of the names, introduced by Linnæus, certainly
appear fanciful enough: thus he gives the name of
Bauhinia to a plant with leaves in pairs, because the
Bauhins were a pair of brothers; Banisteria is the
name of a climbing plant, in honour of Banister, who
travelled among mountains. But such names, once
established by adequate authority, lose all their incon-
venience, and easily become permanent; and hence the
reasonableness of the Linnæan rule32, that as such a
perpetuation of the names of persons by the names
of plants is the only honour botanists have to bestow,
it ought to be used with care and caution.
33
The generic name must, as Linnæus says, be fixed ³³
before we attempt to form a specific name; 'the latter
without the former is like the clapper without the
bell.' The name of the genus being established, the
species may be marked by adding to it 'a single word
taken at will from any quarter;' that is, not involving
a description or any essential property of the plant,
but a casual or arbitrary appellation. Thus the vari-
31 Pp. cxxix. clxxii.
33 Ib. §. 222.
32 Phil. Bot. s. 239.
34 lb. S. 260;
METHODS OF NATURAL HISTORY.
135
35
ous species of Hieracium are Hieracium Alpinum, H.
Halleri, H. Pilosella, H. dubium, H. murorum, &c.
where we see how different may be the kind of origin
of the words.
Attempts have been made at various times to form
"the name of species from those of genera in some
more symmetrical manner. Thus some have num-
bered the species of genus, 1, 2, 3, &c.; but this
method is liable to the inconveniences, first, that it
offers nothing for the memory to take hold of; and
second, that if a new species intermediate between 1
and 2, 2 and 3, &c., be discovered, it cannot be put in
its place. It has also been proposed to mark the species
by altering the termination of the genus. Thus Ādan-
son 36, denoting a genus by the name Fonna (Lychnidea),
conceived he might mark five of its species by altering
the last vowel, Fonna, Fonna-e, Fonna-i, Fonna-o,
Fonna-u; then others by Fonna-ba, Fonna-ka, and so
on. This course would be liable to the same evils
which have been noticed as belonging to the numeri-
cal method.
The names of plants (and the same is true of ani-
mals) have in common practice been binary only,
consisting of a generic and a specific name. The Class
and Order have not been admitted to form part of the
appellation of the species. Indeed it is easy to see
that a name which must be identical in so many
instances as that of an Order would be, would be felt
as superfluous and burdensome. Accordingly, Linnæus
makes it a precept37, that the name of the Class and
the Order must not be expressed but understood: and
hence, he says, Royen, who took Lilium for the name
of a Class, rightly rejected it as a generic name, and
substituted Lirium, with the Greek termination.
Yet we must not too peremptorily assume such
maxims as these to be universal for all classificatory
sciences. It is very possible that it may be found
advisable to use three terms, that of order, genus and
35 Hooker, Fl. Scot. 228.
36 Pref. clxxvi.
37 Phil. Bot. S. 215.
136 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
species, in designating minerals, as is done in Mohs's
nomenclature; for example, Rhombohedral Calc Ha-
loide, Paratomous Hal Baryte.
It is possible also that it may be found useful in
the same science to mark some of the steps of classi-
fication by the termination. Thus it has been proposed
to confine the termination ite to the Order Silicides of
Naumann, as Apophyllite, Stilbite, Leucite, &c., and to
use names of different form in other orders, as Tale
Spar for Brennerite, Pyramidal Titanium Oxide for
Octahedrite. Some such method appears to be the
most likely to give us a tolerable mineralogical nomen-
clature.
SECT. VII.-Diagnosis.
20. German Naturalists speak of a part of the
general method which they call the Characteristik of
Natural History, and which is distinguished from the
Systematik of the science. The Systematick arranges
the objects by means of all their resemblances, the
Characteristick enables us to detect their place in the
arrangement by means of a few of their characters.
What these characters are to be, must be discovered by
observation of the groups and divisions of the system
when they are formed. To construct a collection of such
characters as shall be clear and fixed, is a useful, and
generally a difficult task; for there is usually no appa-
rent connexion between the marks which are used in
discriminating the groups, and the nature of the groups
themselves. They are assumed only because the natu-
ralist, extensively and exactly acquainted with the
groups and the properties of the objects which com-
pose them, sees, by a survey of the field, that these
marks divide it properly.
The Characteristick has been termed by some English
Botanists the Diagnosis of plants; a word which we
may conveniently adopt. The Diagnosis of any genus
or species is different according to the system we follow.
Thus in the Linnæan System the Diagnosis of the Rose
is in the first place given by its Class and Order: it is
METHODS OF NATURAL HISTORY.
137
39 (
Icosandrous, and Polygynous; and then the Generic
Distinction is that the calyx is five-cleft, the tube
urceolate, including many hairy achenia, the receptacle
villous 88. In the Natural System the Rose-Tribe are
distinguished as being Polypetalous dicotyledons,
with lateral styles, superior simple ovaria, regular
perigynous stamens, exalbuminous definite seeds, and
alternate stipulate leaves.' And the true Roses are
further distinguished by having Nuts, numerous,
hairy, terminated by the persistent lateral style and
inclosed within the fleshy tube of the calyx,' &c.
It will be observed that in a rigorous Artificial Sys-
tem the Systematick coincides with the Characteristick ;
the Diataxis with the Diagnosis; the reason why a
plant is put in a division is identical with the mode
by which it is known to be in the division. The Rose
is in the class icosandria, because it has many stamens
inserted in the calyx; and when we see such a set of
stamens we immediately know the class. But this is
not the case with the Diagnosis of Natural Families.
Thus the genera Lamium and Galeopsis (Dead Nettle
and Hemp Nettle) are each formed into a separate
group in virtue of their general resemblances and
differences, and not because the former has one tooth
on each side of the lower lip, and the latter a notch in
its upper lip, though they are distinguished by these
marks.
Thus so far as our Systems are natural, (which, as
we have shown, all systems to a certain extent must
be), the Characteristick is distinct both from a Natural
and an Artificial System; and is, in fact, an Artificial
Key to a Natural System. As being Artificial, it takes
as few characters as possible; as being Natural, its
characters are not selected by any general or prescribed
rule, but follow the natural affinities. The Botanists
who have made any steps in the formation of a natural
method of plants since Linnæus, have all attempted to
give a Diagnosis corresponding to the Diataxis of their
method.
38 Lindley, Nat. Syst. p. 149
39 Ib. pp. 81, 3.
CHAPTER III.
APPLICATION OF THE NATURAL HISTORY METHOD to
MINERALOGY.
I.
TH
:
HE philosophy of the Sciences of Classifica-
tion has had great light thrown upon it by
discussions concerning the methods which are used in
Botany for that science is one of the most complete
examples which can be conceived of the consistent and
successful application of the principles and ideas of
Classification; and this application has been made in
general without giving rise to any very startling para-
doxes, or disclosing any insurmountable difficulties.
But the discussions concerning methods of Mineralo-
gical Classification have been instructive for quite a
different reason: they have brought into view the
boundaries and the difficulties of the process of Classi-
fication; and have presented examples in which every
possible mode of classifying appeared to involve inex-
tricable contradictions. I will notice some of the points
of this kind which demand our attention, referring to
the works published recently by several mineralogists.
In the History of Mineralogy we noticed the at-
tempt made by Mohs and other Germans to apply to
minerals a method of arrangement similar to that
which has been so successfully employed for plants.
The survey which we have now taken of the grounds
of that method will point out some of the reasons of
the very imperfect success of this attempt. We have
already said that the Terminology of Mineralogy was
materially reformed by Werner; and including in this
branch of the subject (as we must do) the Crystal-
lography of later writers, it may be considered as to a
great extent complete. Of the attempts at a Natural
arrangement, that of Mohs appears to proceed by the
APPLICATION TO MINERALOGY.
139
method of blind trial, the undefinable perception of
relationship, by which the earliest attempts at a Natu-
ral Arrangement of plants were made. Breithaupt
however, has made (though I do not know that he has
published) an essay in a mode which corresponds very
nearly to Adanson's process of multiplied comparisons.
Having ascertained the specific gravity and hardness
of all the species of minerals, he arranged them in a
table, representing by two lines at right angles to each
other these two numerical quantities. Thus all mine-
rals were distributed according to two co-ordinates
representing specific gravity and hardness. He con-
ceived that the groups which were thus brought toge-
ther were natural groups. On both these methods, and
on all similar ones, we might observe, that in minerals
as in plants, the mere general notion of Likeness can-
not lead us to a real arrangement: this notion requires
to have precision and aim given it by some other rela-
tion;-by the relation of Chemical Composition in
minerals, as by the relation of Organic Function in
vegetables. The physical and crystallographical pro-
perties of minerals must be studied with reference to
their constitution; and they must be arranged into
Groups which have some common Chemical Character,
before we can consider any advance as made towards a
Natural Arrangement.
In reality, it happens in Mineralogy as it happened
in Botany, that those speculators are regulated by
an obscure perception of this ulterior relation, who
do not profess to be regulated by it. Several of the
Orders of Mohs have really great unity of chemical
character, and thus have good evidence of their being
really Natural Orders.
2. Supposing the Diataxis of minerals thus ob-
tained, Mohs attempted the Diagnosis; and his Cha-
racteristick of the Mineral Kingdom, published in
Dresden, in 1820, was the first public indication of his
having constructed a system. From the nature of a.
Characteristick, it is necessarily brief, and without any
ostensible principle; but its importance was duly ap-
preciated by the author's countrymen. Since that
140 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
time, many attempts have been made at improved
arrangements of minerals, but none, I think, (except
perhaps that of Breithaupt,) professing to proceed
rigorously on the principles of Natural History ;-to
arrange by means of external characters, neglecting
altogether, or rather postponing, the consideration of
chemical properties. By relaxing from this rigour,
however, and by combining physical and chemical con-
siderations, arrangements have been obtained (for
example, that of Naumann,) which appear more likely
than the one of Mohs to be approximations to an ulti-
mate really natural system. Naumann's Classes are
Hydrolytes, Haloides, Silicides, Metal Oxides, Metals,
Sulphurides, Anthracides, with subdivisions of Orders,
as Anhydrous unmetallic Silicides. It may be remarked
that the designations of these are mostly chemical. As
we have observed already, Chemistry, and Mineralogy
in its largest sense, are each the necessary supplement
of the other. If Chemistry furnish the Nomenclature,
Mineralogy must supply the Physiography: if the
Arrangement be founded on External Characters and
the Names be independent of Chemistry, the chemical
composition of each species is an important scientific
Truth respecting it.
3. The inquiry may actually occur, whether any
subordination of groups in the mineral kingdom has
really been made out. The ancient chemical arrange-
ments, for instance, that of Haüy, though professing
to distribute minerals according to Classes, Orders,
Genera, and Species, were not only arbitrary, but inap-
plicable; for the first postulate of any method, that
the species should have constant characters of unity
and difference, was not satisfied. It was not ascertained
that carbonate of lime was really distinguishable in all
cases from carbonate of magnesia, or of iron; yet these
species were placed in remote parts of the system : and
the above carbonates made just so many species; al-
.though, if they were distinct from one another at all,
they were further distinguishable into additional spe-
cies. Even now, we may, perhaps, say that the limits
of mineralogical species, and their laws of fixity, are
APPLICATION TO MINERALOGY.
141
not yet clearly seen. For the discoveries of the iso-
morphous relations and of the optical properties of
minerals have rather shown us in what direction the
object lies, than led us to the goal. It is clear that, in
the mineral kingdom, the Definition of Species, bor-
rowed from the laws of the continuation of the kind,
which holds throughout the organic world, fails us
altogether, and must be replaced by some other condi-
tion nor is it difficult to see that the definite atomic
relations of the chemical constituents, and the definite
crystalline angle, must supply the principles of the
Specific Identity for minerals. Yet the exact limits of
definiteness in both these cases (when we admit the
effect of mechanical mixtures, &c.) have not yet been
completely disentangled. Moreover, any arbitrary as-
sumption (as the allowance of a certain per-centage of
mixture, or a certain small deviation in the angle,) is
altogether contrary to the philosophy of the Natural
System, and can lead to no stable views. It is only
by laborious, extensive, and minute research, that we
can hope to attain to any solid basis of arrange-
ment.
4. Still, though there are many doubts respecting
mineralogical species, a large number of such species
are so far fixed that they may be supposed capable of
being united under the higher divisions of a system
with approximate truth. Of these higher divisions,
those which have been termed Orders appear to tend
to something like a fixed chemical character. Thus
the Haloids of Naumann, and mostly those of Mohs,
are combinations of an oxide with an acid, and thus
resemble Salts, whence their name. The Silicides
contain most of Mohs's Spaths: and the Orders Py-
rites, Glance, and Blende, are common to Naumann
and Mohs; being established by the latter on a differ-
ence of external character, which difference is, indeed,
very manifest; and being included by the former in
one chemical Class, Sulphurides. The distinctions of
Hydrous and Anhydrous, Metallic and Unmetallic,
are, of course, chemical distinctions, but occur as the
differences of Orders in Naumann's mixed system.
142 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
We may observe that some French writers, follow-
ing Hauy's last edition, use, instead of metallic and
unmetallic, autopside metallic and heteropside metallic;
meaning by this phraseology to acknowledge the dis-
covery that earths, &c., are metallic, though they do
not appear to be so, while metals both are and appear
metallic. But this seems to be a refinement not only
useless but absurd. For what is gained by adding the
word metallic, which is common to all, and therefore
makes no distinction? If certain metals are distin-
guished by their appearing to be metals, this appear-
ance is a reason for giving them the peculiar name,
metals. Nothing is gained by first bringing earths and
metals together, and then immediately separating
them again by new and inconvenient names.
No pro-
position can be expressed better by calling earths, heter-
opside metallic substances, and therefore such nomen-
clature is to be rejected.
Granting, then, that the Orders of the best recent
mineralogical systems approximate to natural groups,
we are led to ask whether the same can be said of the
Genera of the Natural History systems, such as those
of Mohs and Breithaupt. And here I must confess
that I see no principle in these Genera; I have failed
to apprehend the conceptions by the application of
which they have been constructed: I shall therefore
not pass any further judgment upon them. The sub-
ordination of Mineralogical Species to Orders is a
manifest gain to science: in the interposition of Genera
I see nothing but a source of confusion.
5. In Mineralogy, as in other branches of natural
history, a reformed arrangement ought to give rise to
a reformed Nomenclature; and for this, there is more
occasion at present in Mineralogy than there was in
Botany at the worst period, at least as far as the ex-
tent of the subject allows. The characters of minerals
are much more dimly and unfrequently developed
than those of plants; hence arbitrary chemical arrange-
ments, which could not lead to any natural groups,
and therefore not to any good names, prevailed till
recently; and this state of things produced an anarchy
APPLICATION TO MINERALOGY.
143
in which every man did what seemed right in his own
eyes, proposed species without any ascertained dis-
tinction, and without a thought of subordination, and
gave them arbitrary names; and thus with only about
two or three hundred known species, we have thou-
sands upon thousands of names, of anomalous form
and uncertain application.
Mohs has attempted to reform the Nomenclature of
the subject in a mode consistent with his attempt to
reform the System. In doing this, he has fatally trans-
gressed a rule always insisted upon by the legislators
of Botany, of altering usual names as little as possible;
and his names are both so novel and so cumbrous,
that they appear to have little chance of permanent
currency. They are, perhaps, more unwieldy than
they need to be, by referring, as we have said, to three
of the steps of his classification, the Species, Genus,
and Order. We may, however, assert confidently, from
the whole analogy of natural history, that no good
names can be found which do not refer to at least two
terms of the arrangement. This rule has been practi-
cally adopted to a great extent by Naumann, who
gives to most of his Haloids the name Spar, as Calc
spar, Iron spar, &c.; to all his Oxides the terminal
word Erz (Ore); and to the species of the orders Kies
(Pyrites), Glance, and Blende, these names. It has
also been theoretically assented to by Beudant, who
proposes that we should say silicate stilbite, silicate
chabasie; carbonate calcaire, carbonate witherite; sul-
phate couperose, &c. One great difficulty in this case
would arise from the great number of silicides; it is
not likely that any names would obtain a footing which
tacked the term silicide to another word for each of
these species. The artifice which I have proposed, in
order to obviate this difficulty, is that we should
make the names of the silicides, and those alone, end
in ite or lite, which a large proportion of them do
already.
By this and a few similar contrivances, we might,
I conceive, without any inconvenient change, introduce
into Mineralogy a systematic nomenclature.
144 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
元
​6. I shall now proceed to make a few remarks on
a work on Mineralogy more recent than those which I
have above noticed, and written with express reference
to such difficulties as I have been discussing. I allude
to the treatise of M. Necker, Le Règne Mineral ramené
aux Methodes d'Histoire Naturelle', which also con-
tains various dissertations on the Philosophy of Classi-
fication in general, and its application to Mineralogy
in particular.
M. Necker remarks very justly, that Mineralogy,
as it has hitherto been treated, differs from all other
branches of Natural History in this:-that while it is
invested with all the forms of the sciences of classifica-
tion, Classes, Divisions, Genera, and the like,-the
properties of those bodies to which the mineralogical
student's attention is directed have no bearing what-
ever on the classification. A person, he remarks",
might be perfectly well acquainted with all the charac-
ters of minerals which Werner or Haüy examined so
carefully, and might yet be quite unable to assign to
any mineral its place in the divisions of their methods.
There is a complete separation between the study of
mineralogical characters and the recognition of the
name and systematic place of a mineral. Those who
know mineralogy well, may know minerals ill, or
hardly at all; the systematist may be in such know-
ledge vastly inferior to the mineral-dealer or the
miner. In this respect there is a complete contrast
between this science and other classificatory sciences.
3
Again, in the best-known systems of Mineralogy, (as
those of Werner and Haüy,) the bodies which are
grouped together as belonging to the same division,
have not, as they have in other classificatory sciences,
any resemblance. The different members of the larger
classes are united by the common possession of some
abstract property,-as, that they all contain iron. This
is a property to which no common circumstance in
the bodies themselves corresponds. What is there com-
mon to the minerals named oxidulous iron, sulphuret
1 Paris, 1835.
2 Règne Mineral, p. 3.
3 Ib. p. 8.
APPLICATION TO MINERALOGY.
145
of iron, carbonate of iron, sulphate of iron, except that
they all contain iron? And when we have classed these
bodies together, what general assertion can we make
concerning them, except that which is the ground of
our classification, that they contain iron? They have
nothing in common with iron or with each other in
any other way.
Again, as these classes have no general properties,
all the properties are particular to the species; and the
descriptions of these necessarily become both tediously
long, and inconveniently insulated.
7. These inconveniences arise from making Chemi-
cal Composition the basis of Mineralogical Classifica-
tion without giving Chemical Analysis the first place
among Mineral Properties. Shall we, then, correct this
omission, so far as it has affected mineralogical sys-
tems? Shall we teach the student the chemical analy-
sis of minerals, and then direct him to classify them
according to the results of his analysis*?
But why should we do this? To what purpose, or
on what ground, do we arrange the results of chemical
analysis according to the forms and subordination of
natural history? Is not Chemistry a science distinct
from Natural History? Are not the sciences opposed?
Is not natural history confined to organic bodies? Can
mere chemical elements and their combinations be,
with any propriety or consistency, arranged into Spe-
cies, Genera, and Families? What is the principle
on which genera and species depend? Do not Species
imply Individuals? What is an Individual in the case
of a chemical substance?
8. We thus find some of the widest and deepest
questions of the philosophy of classification brought
under our consideration when we would provide a
method for the classification of minerals. The answers
to these questions are given by M. Necker; and I shall
state some of his opinions; taking the liberty of adding
such remarks as are suggested by referring the subject
4 Règne Mineral, p. 18.
VOL. II.
L
146 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
to those principles which have already been established
in this work.
5
M. Necker asserts that the distinctions of different
Sciences depend, not on the objects they consider, but
on the different and independent points of view on
which they proceed. Each science has its logic, that
is, its mode of applying the general rules of human
reason to its own special case. It has been said by
some, that in minerals, natural history and chemistry
contemplate common objects, and thus form a single
science. But do chemistry and natural history con-
sider minerals in the same point of view?
The answer is, that they do not. Physics and Che-
mistry consider the properties of bodies in an abstract
manner; as, their composition, their elements, their
mutual actions, with the laws of these; their forces, as
attraction, affinity; all which objects are abstract ideas.
In these cases we have nothing to do with bodies
themselves, but as the vehicles of the
perties which we contemplate.
powers and
pro-
Natural History, on the other hand, has to do with
natural bodies: their properties are not considered ab-
stractedly, but only as characters. If the properties
are abstracted, it is but for a moment. Natural his-
tory has to describe and class bodies as they are. All
which cannot be perceived by the senses, belongs not
to its domain, as molecules, atoms, elements.
Natural history' may have recourse to physics or
chemistry in order to recognize those properties of
bodies which serve as characters; but natural history
is not, on that account, physics or chemistry. Classi-
fication is the essential business of the natural his-
torian, to which task chemistry and physics are only
instrumental, and the further account of properties
only complementary.
>
It has been said, in support of the doctrine that
chemistry and mineralogy are identical, that chemistry
does not neglect external characters. "The chemist in
5 Règne Mineral, p. 23.
7 Ib. p. 37.
6 Ib. p. 27.
8 Ib. p. 41.
APPLICATION TO MINERALOGY.
147
describing sulphur, mentions its colour, taste, odour,
hardness, transparence, crystalline form, specific gra-
vity; how does he then differ from the mineralogist?'
But to this it is replied, that these notices of the
external characters of this or any substance are intro-
duced in chemistry merely as convenient marks of
recognition; whereas they are essential in mineralogy.
If we had taken the account given of several sub-
stances instead of one, we should have seen that the
chemist and the naturalist consider them in ways alto-
gether different. The chemist will make it his busi-
ness to discover the mutual action of the substances;
he will combine them, form new products, determine
the proportions of the elements. The mineralogist will
divide the substances into groups according to their
properties, and then subdivide these groups, till he
refers each substance to its species. Exterior and phy-
sical characters are merely accessory and subordinate
for the chemist; chemistry is merely instrumental for
the mineralogist.
This view agrees with that to which we have been
led by our previous reasonings; and may, according to
our principles, be expressed briefly by saying, that the
Idea which Chemistry has to apply is the Idea of Ele-
mentary Composition, while Natural History applies
the Idea of Graduated Resemblances, and thus per-
forms the task of classification.
9. The question occurs, whether Natural History
can be applied to Inorganic Substances? And the
answer to this question is, that it can be applied, if
there are such things as inorganic individuals, since
the resemblances and differences with which natural
history has to do are the resemblances and differences
of individuals.
What is an Individual? It certainly is not that
which is so simple that it cannot be divided. Indi-
vidual animals are composed of many parts. But if
we examine, we shall find that our Idea of an Indi-
vidual is, that it is a whole composed of parts, which
9 Règne Mineral, p. 46.
L 2
148 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
are not similar to the whole, and have not an inde-
pendent existence, while the whole has an independent
existence and a definite form 10.
What then is the Mineralogical Individual?
first, while minerals were studied for their use, the
most precious of the substances which they contained
was looked upon as the characteristic of the mineral.
The smallest trace of silver made a mineral an ore of
silver. Thus forms and properties were disregarded,
and substance was considered as identical with mineral.
And hence" Daubenton refused to recognize species in
the mineral kingdom, because he recognized no indivi-
duals. He proposed to call sorts what we call species.
In this way of considering minerals, there are no indi-
viduals.
IO.
But still this is not satisfactory: for if we take
a well-formed and distinct crystal, this clearly is an
individual ¹².
It may be objected, that the crystal is divisible
(according to the theory of crystallography) into smaller
solids; that these small solids are really the simple
objects; and that actual crystals are formed by com-
binations of these molecules according to certain laws.
But, as we have already said, an individual is such,
not because it cannot be divided, but because it cannot
be divided into parts similar to the whole. As to the
division of the form into its component laws, this is an
abstract proceeding, foreign to natural history 13. There-
fore there is so far nothing to prevent a crystal from
being an individual.
II. We cannot (M. Necker goes on to remark)
consider the Integrant Molecules as individuals. These
are useful abstractions, but abstractions only, which
we must not deal with as real objects. Haüy himself
14 that his doctrine of increments is a purely
abstract conception, and that nature, in fact, follows a
different process. Accordingly, Weiss and Mohs ex-
press laws identical with those of Haüy, without even
warns us
10 Règne Mineral, p. 52.
12 Ib. p. 56.
11 Tb. p. 54.
13 Ib. p. 58.
14 Ib. p. 61.
APPLICATION TO MINERALOGY.
149
speaking of molecules; and Wollaston and Davy have
deemed it probable that the molecules are not poly-
hedrons, but spheres or spheroids. Such mere crea-
tions of the mind can never be treated as individuals.
If the maxim of natural history,-that the Species is a
collection of Individuals-be applied so as to make
those individuals mere abstractions; or if, instead of
Individuals, we take such an abstraction as Substance
or Matter, the course of natural history is altogether
violated. And yet this errour has hitherto generally
prevailed; and mineralogists have classified, not things,
but abstract ideas ¹5.
12. But it may be said 16, will not the small solids
obtained by Cleavage better answer the idea of indi-
viduals? To this it is replied, that these small solids
have no independent existence. They are only the
result of a mode of division. They are never found
separate and independent. The secondary forms which
they compose are determined by various circumstances
(the nature of the solution, &c.); and the cleavage
which produces these small solids is only one result
among many, from the crystalline forces".
Thus neither Integrant Molecules, nor Solids ob-
tained by Cleavage, can be such mineralogical Indivi-
duals as the spirit of natural history requires. Hence
it appears that we must take the real Crystals for
Individuals 18.
13. We must, however, reject crystals (generally
large ones) which are obviously formed of several
smaller ones of a similar form (as occurs so often in
quartz and calc spar). We must also distinguish cases
in which a large regular form is composed of smaller
but different regular forms (as octahedrons of fluor
spar made up of cubes). Here the small component
forms are the individuals. Also we must notice the
19 in which we have a natural crystal, similar to
the primary form. Here the face will show whether
cases
16 Ib. p. 69.
15 Règne Mineral, p. 67.
17 Ib. p. 71.
18 Пb. p. 73.
19 Ib. p. 75-
150 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
the body is a result obtained by cleavage or a natural
individual.
14. It will be objected 20, that the crystalline form
ought not to be made the dominant character in mine-
ralogy, since it rarely occurs perfect. To this it is
replied, that even if the application of the principle be
difficult, still it has been shown to be the only true
principle, and therefore we have no alternative. But
further", it is not true that amorphous substances are
more numerous than crystals. In Leonhard's Manual
of Oryctognosy, there are 377 mineral substances. Of
these, 281 have a crystalline structure, and 96 only
have not been found in a regular form.
Again, the 281 crystalline forms have each its varie-
ties, some of which are crystalline, and some are not
So. Now the crystalline varieties amount to 1453, and
the uncrystalline to 186 only. Thus mineralogy, ac-
cording to the view of it here presented, has a suffi-
ciently wide field 22.
15. It will be objected 23, that according to this
mode of proceeding, we must reject from our system
all non-crystalline minerals. But we reply, that if
the mass be composed of crystals, the size of the crys-
tals makes no difference. Now lamellar and other
compact masses are very generally groups of crystals in
various positions. Individuals mutilated and mixed
together are not the less individuals; and therefore
such masses may be treated as objects of natural
history.
If we cannot refer all rocks to crystalline species,
those which elude our method may appear as an ap-
pendix, corresponding to those plants which botanists
call genera incerta sedis 24.
But these genera and species will often be after-
wards removed into the crystalline part of the system,
by being identified with crystalline species. Thus
pyrope, &c., have been referred to garnet, and basalt,
22 Ib. p. 84.
20 Règne Mineral, p. 79
28 lb. p. 86.
21 Ib. p. 82.
24 Ib. P. 91.
APPLICATION OF MINERALOGY.
151
wacke, &c., to compound rocks. Thus veins of Dolerite,
visibly composed of two or three elements, pass to an
apparently simple state by becoming fine-grained 25.
16. Finally 26, we have to ask, are artificial crystals
to enter into our classification? M. Necker answers,
No; because they are the result of art, like mules,
mestizos, hybrids, and the like.
17. Upon these opinions, we may observe, that they
appear to be, in the main, consistent with the soundest
philosophy. That each natural crystal is an individual,
is a doctrine which is the only basis of Mineralogy as a
Natural Historical Science; yet the imperfections and
confused unions of crystals make this principle difficult
to apply. Perhaps it may be expressed in a more pre-
cise manner by referring to the crystalline forces, and
to the axes by which their operation is determined,
rather than to the external form. That portion of a
mineral substance is a mineralogical individual which
is determined by crystalline forces acting to the same
axes. In this way we avoid the difficulty arising from
the absence of faces, and enable ourselves to use either
cleavage, or optical properties, or any others, as indi-
cations of the identity of the individual. The indi-
vidual extends so far as the polar forces extend by
which crystalline form is determined, whether or not
those forces produce their full effect, namely, a per-
fectly circumscribed polyhedron.
18. There is only one material point on which our
principles lead us to differ from M. Necker ;—the pro-
priety of including artificial crystals in our mineralo-
gical classification. To exclude them, as he does, is a
conclusion so entirely at variance with the whole
course of his own reasonings, that it is difficult to con-
ceive that he would persist in his conclusion, if his
attention were drawn to the question more steadily.
For, as he justly says", each science has its appropriate
domain, determined by its peculiar point of view.
Now artificial and natural crystals are considered in
the same point of view, (namely, with reference to
25 Règne Mineral, p. 93.
26 Ib. p. 95.
27 Ib. p. 23.
152 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
crystalline, physical, and optical properties, as subser-
vient to classification,) and ought, therefore, to belong
to the same science. Again, he says 23, that Chemistry
would reject as useless all notice of the physical pro-
perties and external characters of substances, if a
special science were to take charge of the description
and classification of these products. But such a special
science must be Mineralogy; for we cannot well make
one science of the classification of natural, and another
of that of artificial substances: or if we do, the two
sciences will be identical in method and principles,
and will extend over each other's boundaries, so that
it will be neither useful nor possible to distinguish
them. Again, M. Necker's own reasonings on the
selection of the individual in mineralogy are supported
by well chosen examples 29; but these examples are
taken from artificial salts; as, for instance, common
salt crystallizing in different mixtures. Again, the
analogy of mules and mestizos, as products of art, with
chemical compounds, is not just. Chemical compounds
correspond rather to natural species, propagated by
man under the most natural circumstances, in order
that he may study the laws of their production 3º.
30
19. But the decisive argument against the separa-
tion of natural and artificial crystals in our schemes of
classification is, that we cannot make such a separa-
tion. Substances which were long known only as the
products of the laboratory, are often discovered, after
a time, in natural deposits. Are the crystals which
are found in a forgotten retort or solution to be con-
sidered as belonging to a different science from those
which occur in a deserted mine? And are the crystals
which are produced where man has turned a stream of
water or air out of its course, to be separated from
natural crystals, when the composition, growth, and
properties, are exactly the same in both? And again :
How many natural crystals can we already produce by
28 Règne Mineral, p. 36.
29 Ib. p. 71.
30 We may remark that M. Necker, in his own arrangement of minerals,
inserts among his species Iron and Lead, which do not occur Native.
APPLICATION OF MINERALOGY.
153
synthesis! How many more may we hope to imitate
hereafter! M. Necker himself states 3, that Mitscher-
lich found, in the scoriæ of the mines of Sweden and
Germany, artificial minerals having the same composi-
tion and the same crystalline form with natural mine-
rals: as silicates of iron, lime, and magnesia, agreeing
with Peridot; bisilicate of iron, lime, and magnesia,
agreeing with Pyroxene; red oxide of copper; oxide
of zinc; protoxide of iron (fer oxydule); sulphurets
of iron, zinc, lead; arseniuret of nickel; black mica.
These were accidental results of fusion. But M. Ber-
thier, by bringing together the elements in proper
quantities, has succeeded in composing similar mine-
rals, and has thus obtained artificial silicates, with the
same forms and the same characters as natural silicates.
Other chemists (M. Haldat, M. Becquerel) have, in
like manner, obtained, by artificial processes, other
crystals, known previously as occurring naturally.
How are these crystals, thus identical with natural
minerals, to be removed out of the domain of minera-
logy, and transferred to a science which shall classify
artificial crystals only? If this be done, the minera-
logist will not be able to classify any specimen till he
has human testimony whether it was found naturally
occurring or produced by chemical art. Or is the
other alternative to be taken, and are these crystals
to be given up to mineralogy because they occur natu-
rally also? But what can be more unphilosophical
than to refer to separate sciences the results of chemi-
cal processes closely allied, and all but identical? The
chemist constructs bisilicates, and these are classified
by the mineralogist: but if he constructs a trisilicate,
it belongs to another science. All these intolerable
incongruities are avoided by acknowledging that arti-
ficial, as well as natural, crystals belong to the domain
of mineralogy. It is, in fact, the name only of Mine-
ralogy which appears to discover any inconsistency in
this mode of proceeding. Mineralogy is the represen-
31 Règne Mineral, p. 151.
154 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
tative of a science which has a wider office than mine-
ralogists first contemplated; but which must exist, in
order that the body of science may be complete. There
must, as we have already said, be a Science, the object
of which is to classify bodies by their physical cha-
racters, in order that we may have some means of
asserting chemical truths concerning bodies; some
language in which we may express the propositions
which chemical analysis discovers. And this Science
will have its object prescribed, not by any accidental
or arbitrary difference of the story belonging to each
specimen ;-not by knowing whether the specimen
was found in the mine or in the laboratory; produced
by attempting to imitate nature, or to do violence to
her :—but will have its course determined by its own
character. The range and boundaries of this Science
will be regulated by the Ideas with which it deals.
Like all other sciences, it must extend to everything
to which its principles apply. The limits of the pro-
vince which it includes are fixed by the consideration
that it must be a connected whole. No previous defi-
nition, no historical accident, no casual phrase, can at
all stand in the way of philosophical consistency;-can
make this Science exclude what that includes, or
oblige it to admit what that rejects. And thus, what-
ever we call our Science ;-whether we term it Exter-
nal Chemistry, Mineralogy, the Natural History of
Inorganic Bodies;-since it can be nothing but the
Science of the Classification of Inorganic Bodies of
definite forms and properties, it must classify all such
bodies, whether or not they be minerals, and whether
or not they be natural.
20. In the application of the principles of classifica-
tion to minerals, the question occurs, What are to be
considered as mineral Species? By Species we are to
understand, according to the usage of other parts of
natural history, the lowest step of our subordinate
divisions;—the most limited of the groups which have
definite distinctions. What definite distinctions of
groups of objects of any kind really occur in nature, is
to be learnt from an examination of nature: and the
APPLICATION OF MINERALOGY.
155
result of our inquiries will be some general principle
which connects the members of each group, and distin-
guishes the members of groups which, though contigu-
ous, are different. In the classification of organized
bodies, the rule which thus presides over the formation
of Species is the principle of reproduction. Those ani-
mals and those plants are of the same Species which
are produced from a common stock, or which resemble
each other as much as the progeny of a common stock.
Accordingly in practice, if any questions arise whether
two varieties of form in organic things be of the same
or different species, it is settled by reference to the
fact of reproduction; and when it is ascertained that
the two forms come within the habitual and regular
limits of a common circle of reproduction, they are held
to be of the same species. Now in crystals, this principle
of reproduction disappears altogether, and the basis of
the formation of species must be sought elsewhere. We
must have some other principle to replace the repro-
duction which belongs only to organic life. This prin-
ciple will be, we may expect, one which secures the
permanence and regularity of mineral forms, as the
reproductive power does of animal and vegetable. Such
a principle is the Power of Crystallization. The forces
of which solidity, cohesion, and crystallization are the
result, are those which give to minerals their perma-
nent existence and their physical properties; and ever
since the discovery of the distinctions of Crystalline
Forms and Crystalline Systems, it is certain that this
force distinguishes groups of crystals in the most pre-
cise and definite manner. The rhombohedral carbo-
nates of lime and of iron, for instance, are distinguished
exactly by the angles of their rhombohedrons. And
if, in the case of any proposed crystal, we should doubt
to which kind the specimen belongs, the measurement
of the angles of cleavage would at once decide the
question. The principle of Crystallization therefore ap-
pears, from analogy, to be exactly fitted to take the
place of the principle of organic Generation. The forces
which make the individual permanent and its proper-
ties definite, here stand in the place of the forces
156 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
which preserve the race, while individuals are gene-
rated and die.
21.
According to this view, the different Modifica-
tions of the same crystalline form would be Varieties
only of the same Species. All the various solids, for
example, which are produced by the different laws of
derivation of rhombohedral carbonate of lime, would
fall within the same Species. And this appears to be
required by the general analogy of Natural History.
For these differences of form, produced by the laws of
crystalline derivation, are not definite. The faces
which are added to one form in order to produce
another, may be of any size, small or large, and thus
the crystal which represents one modification passes by
insensible degrees to another. The forms of calc spar,
which we call dog-tooth spar, cannon spar, nail-head
spar, and the like, appear at first, no doubt, distinct
enough; but so do the races of dogs. And we find, in
the mineral as in the animal, that the distinction is
obliterated by taking such intermediate steps as really
occur. And if a fragment of any of these crystals is
given us, we can determine that it is rhombohedral
carbonate of lime; but it is not possible, in general,
to determine to which of the kinds of crystals it has
belonged.
Thus
22. Notwithstanding these considerations, M. Necker
has taken for his basis of mineral species 32 the Second-
ary Modifications, and not the Primary Forms.
cubical galena, octahedral galena, and triform galena,
are, with him, three species of crystals.
On this I have to observe, as I have already done,
that on this principle we have no definite distinction of
species; for these forms may and do pass into each
other: among cubo-octahedrons of galena occur cubes
and octahedrons, as one face or another vanishes, and
the transition is insensible. We shall, on this principle,
find almost always three or four species in the same
tuft of crystals; for almost every individual in such
assemblages may exhibit a different combination of
32 Règne Mineral, p. 396.
APPLICATION OF MINERALOGY.
157
secondary faces. Again, in cases where the secondary
laws are numerous, it would be impracticable to enu-
merate all their combinations, and impossible therefore
to give a list of species. Accordingly M. Necker 3 gives
seventy-one Species of spath calcaire, and then says,
'Nous n'avons pas énuméré la dixième partie des
espèces connues de ce genre, qui se montent à plus de
huit cents.' Again, in many substances, of which few
crystals are found, every new specimen would be a
new species; if indeed it were perfect enough to be
referred to a species at all. But from a specimen
without perfect external form, however perfect in
crystalline character, although everything else might
be known,—angles, optical properties, physical proper-
ties, and chemical constitution, the species could not
be determined. Thus M. Necker says 34 of the micas,
Quant aux espèces propre à chaque genre, la lacune
sera presque complète; car jusqu'ici les cristaux entiers
de Mica et de Talc n'ont pas été fort communs.'
(
These inconveniences arise from neglecting the lead-
ing rule of natural history, that the predominant prin-
ciple of the existence of an object must determine the
Species; whether this principle be Reproduction ope-
rating for Development, or Crystallization operating
for Permanence of form. We may add to the above
statement of inconveniences this;—that if M. Necker's
view of mineralogical species be adopted, the distinc-
tion of Species is vague and indefinite, while that of
Genera is perfectly precise and rigorous;—an aspect
of the system entirely at variance with other parts of
Natural History; for in all these the Species is a more
definite group than the Genus.
This result follows, as has already been said, from
M. Necker's wish to have individuals marked by ex-
ternal form. If, instead of this, we are contented to
take for an individual that portion of a mass, of what-
ever form, which is connected by the continuous influ-
ence of the same crystalline forces, by whatever inci-
dents these forces may be manifested, (as cleavage,
33 Règne Mineral, p. 364.
34 Tb. ii. 414.
158 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
physical and optical properties, and the like,) our
mode of proceeding avoids all the above inconveni-
ences, applies alike to the most perfect and most im-
perfect specimens, and gives a result agreeable to the
general analogy of natural history, and the rules of its
methods 35.
I now quit the subject of mere Resemblance, and
proceed to treat of that natural affinity which Natural
Systems of Classification for organic bodies must in-
volve.
35 I will not again enter into the
subject of Nomenclature; but I may
remark that M. Necker has adopted
(i. 415) the Nomenclature of Beudant,
latinizing the names, and thus con-
verting each into a single word. He
has also introduced, besides the
names of Genera, names of Fami-
lies taken from the typical Genus.
Thus the Family of Carbonidiens
contains the following genera: Cal-
cispathum, Magnesispathum, Dolo-
mispathum, Ferrispathum, &c., Ma-
lachita, Azuria, Gaylusacia.
CHAPTER IV.
OF THE IDEA OF NATURAL AFFINITY.
I.
IN
N the Second Chapter of this Book it was
shown that although the Classificatory Sci-
ences proceed ostensibly upon the Idea of Resemblance
as their main foundation, they necessarily take for
granted in the course of their progress a further Idea
of Natural Affinity. This appeared' by a general con-
sideration of the nature of Science, by the recognition
of natural species and genera, even in Artificial Sys-
tems of Classification, and by the attemps of botanists
to form a Natural System. It further appeared that
among the processes by which endeavours have been
made to frame a Natural System, some, as the method
of Blind Trial and the method of General Comparison,
have been altogether unsuccessful, being founded only
upon a collection of resemblances, casual in the one
case and arbitrary in the other. In neither of these
processes is there employed any general principle by
which we may be definitely directed as to what resem-
blances we should employ, or by which the result at
which we arrive may be verified and confirmed. Our
object in the present chapter is to show that the Idea
of Natural Affinity supplies us with a principle which
may answer such purposes.
I shall first consider the Idea of Affinity as exempli-
fied in organized beings. In doing this, we may appear
to take for granted Ideas which have not yet come
under our discussion, as the Ideas of Organization, and
Vital Function; but it will be found that the principle
to which we are led is independent of these additional
Ideas.
1 Art. 5.
2 Art. 7.
160 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
2. We have already seen that the attempts to dis-
cover the divisions which result from this Natural
Affinity have led to the consideration of the Subordi-
nation of Characters. It is easy to see that some
organs are more essential than others to the existence
of an organized being; the organs of nutrition, for
example, more essential than those of locomotion. But
at the same time it is clear that any arbitrary assump-
tion of a certain scale of relative values of different
kinds of characters will lead only to an Artificial Sys-
This will happen, if, for example, we begin by
declaring the nutritive to be superior in importance to
the reproductive functions. It is clear that this rela-
tion of importance of organs and functions must be
collected by the study of the organized beings; and
cannot be determined à priori, without depriving us
of all right to expect a general accordance between our
system and the arrangement of nature. We see, there-
fore, that our notion of Natural Affinity involves in it
this consequence;—that it is not to be made out by an
arbitrary subordination of characters.
tem.
3. The functions and actions of living things which
we separate from each other in our consideration, can-
not be severed in nature. Each function is essential;
Life implies a collection of movements, and ceases
when any of these movements is stopped. A change
in the organization subservient to one set of functions
may lead necessarily to a change in the organization
belonging to others. We can often see this necessary
connexion; and from a comparison of the forms of
organized beings,-from the way in which their struc-
ture changes in passing from one class to another, we
are led to the conviction that there is some general
principle which connects and graduates all such changes.
When the circulatory system changes, the nervous
system changes also: when the mode of locomotion
changes, the respiration is also modified.
4. These corresponding changes may be considered
as ways in which the living thing is fitted to its mode
of life; as marks of adaptation to a purpose; or, as it
has been otherwise expressed, as results of the condi-
IDEA OF NATURAL AFFINITY,
161
tions of existence. But at the present moment, we put
forward these correspondencies in a different light.
We adduce them as illustrations of what we mean by
Affinity, and what we consider as the tendency of a
Natural Classification. It has sometimes been asserted
that if we were to classify any of the departments of
organized nature by means of one function, and then
by means of another, the two classifications, if each
strictly consistent with itself, would be consistent with
each other. Such an assertion is perhaps more than
we are entitled to make with confidence; but it shows
very well what is meant by Affinity.
meant by Affinity. The disposition.
to believe such a general identity of all partial natural
classifications, shows how readily we fix upon the
notion of Affinity, as a general result of the causes
which determine the forms of living things. When
these causes or principles, of whatever nature they are
conceived to be, vary so as to modify one part of the
organization of the being, they also modify another:
and thus the groups which exhibit this variation of
the fundamental principles of form, are the same,
whether the manifestation of the change be sought in
one part or in another of the organized structure. The
groups thus formed are related by Affinity; and in
proportion as we find the evidence of more functions
and more organs to the propriety of our groups, we
are more and more satisfied that they are Natural
Classes. It appears, then, that our Idea of Affinity
involves the conviction of the Coincidence of natural
arrangements formed on different functions; and this,
rather than the principle of the Subordination of some
characters to others, is the true ground of the natural
method of Classification.
5. For example, Cuvier, after speaking of the Sub-
ordination of Characters as the guide which he intends
to follow in his arrangement of animals, interprets this
principle in such a manner³ as to make it agree nearly
with the one just stated: "In pursuance of what has
been said on methods in general, we now require to
VOL. II.
3 Règne Animal, p. 55.
M
162 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
(
know what characters in animals are the most influen-
tial, and therefore those which must be made the
grounds of the primary divisions.' These,' he says,
'it is clear must be those which are taken from the
animal functions ;-sensation and motion:'-But how
does he confirm this? Not by showing that the animal
functions are independent of, or predominant over, the
vegetative, but by observing that they follow the same
gradations. 'Observation,' he continues, 'confirms
this view, by showing that the degrees of development
and complication of the animal functions agree with
those of the vegetative. The heart and the organs of
the circulation are a sort of center for the vegetative
functions, as the brain and the trunk of the nervous
system are for the animal functions. Now we see
these two systems descend in the scale, and disappear
the one with the other. In the lowest animals, when
there are no longer any distinct nerves, there are also
no longer distinct fibres, and the organs of digestion
are simply hollowed out in the homogeneous mass of
the body. The muscular system disappears even be-
fore the nervous, in insects; but in general the distri-
bution of the medullary masses corresponds to that of
the muscular instruments; a spinal cord, on which
knots or ganglions represent so many brains, corre-
sponds to a body divided into numerous rings and
supported on pairs of members placed at different
points of the length, and so on.
This correspondence of the general forms which
result from the arrangement of the motive organs,
from the distribution of the nervous masses, and from
the energy of the circulatory system, must therefore
form the ground of the first great sections by which
we divide the animal kingdom.
6. Decandolle takes the same view. There must
be, he says, an equilibrium of the different functions*.
And he exemplifies this by the case of the distinction
of monocotyledonous and dicotyledonous plants, which
being at first established by means of the organs of re-
• Theor. Elem. P. 79.
ì
IDEA OF NATURAL AFFINITY.
163
production, was afterwards found to coincide with the
distinction of endogenous and exogenous, which de-
pends on the process of nutrition. Thus,' he adds,
the natural classes founded on one of the great func-
tions of the vegetable are necessarily the same as those
which are founded upon the other function; and I
find here a very useful criterion to ascertain whether a
class is natural: namely, in order to announce that it
is so, it must be arrived at by the two roads which
vegetable organization presents. Thus I affirm,' he
says, 'that the division of monocotyledons from dico-
tyledons, and the distinction of Gramineæ from Cyper-
aceæ, are real, because in these cases, I arrive at the
same result by the reproductive and the nutritive
organs; while the distinction of monopetalous and
polypetalous, of Rhodoraces and Ericineæ, appears to
me artificial, because I can arrive at it only by the
reproductive organs.'
Thus the Correspondence of the indications of dif-
ferent functions is the criterion of Natural Classes;
and this correspondence may be considered as one of
the best and most characteristic marks of the funda-
mental Idea of Affinity. And the Maxim by which
all Systems professing to be natural must be tested is
this: that the arrangement obtained from one set of
characters coincides with the arrangement obtained
from another set.
This Idea of Affinity, as a natural connexion among
various species, of which connexion all particular re-
semblances are indications, has principally influenced
the attempts at classifying the animal kingdom. The
reason why the classification in this branch of Natural
History has been more easy and certain than that of
the vegetable world is, as Decandolle says, that be-
sides the functions of nutrition and reproduction, which
animals have in common with plants, they have also
in addition the function of sensation; and thus have a
new means of verification and concordance. But we
may add, as a further reason, that the functions of
5 Theor. Elem. p. 80.
M 2
164 PHILOSOPHY OF CLASSIFICATORY SCIENCES.
animals are necessarily much more obvious and intel-
ligible to us than those of vegetables, from their clear
resemblance to the operations which take place in our
own bodies, to which our attention has necessarily been
strongly directed.
7. The question here offers itself, whether this Idea
of Natural Affinity is applicable to inorganic as well
as to organic bodies ;-whether there be Natural Affi-
nities among Minerals. And to this we are now
enabled to reply by considering whether or not the
principle just stated is applicable in such cases. And
the conclusion to which our principle leads us is,-
that there are such Natural Affinities among Minerals,
since there are different sets of characters which may
be taken, (and have by different writers been taken,)
as the basis of classification. The hardness, specific
gravity, colour, lustre, crystallization, and other exter-
nal characters, as they are termed, form one body of
properties according to which minerals may be classi-
fied; as has in fact been done by Mohs, Breithaupt,
and others. The chemical constitution of the sub-
stances, on the other hand, may be made the principle
of their arrangement, as was done by Haüy, and more
recently, and on a different scheme, by Berzelius.
Which of these is the true and natural classification?
To this we answer, that each of these arrangements is
true and natural, then, and then only, when it coin-
cides with the other. An arrangement by external
characters which gives us classes possessing a common
chemical character;—a chemical order which brings
together like and separates unlike minerals;—such
classifications have the evidence of truth in their
agreement with one another. Every classification of
minerals which does not aim at and tend to such a
result, is so far merely arbitrary; and cannot be sub-
servient to the expression of general chemical and
mineralogical truths, which is the proper purpose of
such a classification.
8. In the History of Mineralogy I have related
the advances which have been made among mineralo-
gists and chemists in modern times towards a System
IDEA OF NATURAL AFFINITY.
165
possessing this character of truth. I have there de-
scribed the mixed systems of Werner and Haüy ;—the
attempt made by Mohs to form a pure Natural History
system;-the first and second attempt of Berzelius to
form a pure chemical system; and the failure of both
these attempts. But the distinct separation of the two
elements of which science requires the coincidence
threw a very useful light upon the subject; and the
succeeding mixed systems, such as that of Naumann,
approached much nearer to the true conditions of the
problem than any of the preceding ones had done.
Thus, as I have stated, several of Naumann's groups
have both a common chemical character and great
external resemblances. Such are his Anhydrous Un-
metallic Haloids—his Anhydrous Metallic Haloids—
Hydrous Metallic Haloids-Oxides of metals-Pyrites
Glances-Blendes. The existence of such groups
shows that we may hope ultimately to obtain a classi-
fication of minerals which shall be both chemically
significant, and agreeable to the methods of Natural
History: although when we consider how very im-
perfect as yet our knowledge of the chemical composi-
tion of minerals is, we can hardly flatter ourselves
that we shall arrive at such a result very soon.
We have thus seen that in Mineralogy, as well as
in the sciences which treat of organized bodies, we may
apply the Idea of Natural Affinity; of which the fun-
damental maxim is, that arrangements obtained from
different sets of characters must coincide.
Since the notion of Affinity is thus applicable to
inorganic as well as to organic bodies, it is plain that
it is not a mere modification of the Idea of Organiza-
tion or Function, although it may in some of its aspects
appear to approach near to these other Ideas. But
these Ideas, or others which are the foundation of
them, necessarily enter in a very prominent and funda-
mental manner into all the other parts of Natural
History. To the consideration of these, therefore, we
shall now proceed.
BOOK IX.
THE
PHILOSOPHY
OF
BIOLOGY.
La vie est donc un TOURBILLON plus ou moins rapide, plus
ou moins compliqué, dont la direction est constante, et qui
entraine toujours des molecules de mêmes sorts, mais où les
molecules individuelles entrent et d'où elles sortent continu-
ellement, de manière que la Forme du corps vivant lui est plus
essentielle que sa Matière.
Tant que ce mouvement subsiste, le corp où il s'exerce est
vivant; il vit. Lorsque le mouvement s'arrête sans retour, le
corps meurt.
CUVIER, Règne Animal, s. 12.
I REMEMBER, upon asking our famous Harvey, what induced
him to think of a circulation of the blood, he said, that observing
the valves in the veins of many parts of the body, so placed as to
give a free passage to the blood towards the heart, but to oppose
the passage of the venal blood the contrary way, he imagined
that so provident a cause as nature had not thus placed so many
valves without design; and as no design seemed more probable
than that the blood could not well, because of the interposing
valves, be sent by the veins to the limbs, it should be sent through
the arteries and return through the veins when valves did not
oppose its course that way.
BOYLE, On the Final Causes of Natural Things. On the
Proposition: 'Tis often allowable for a naturalist, from the
manifest and apposite uses of the parts of animal bodies, to collect
some of the particular ends for which the Creator designed them:
and in some cases we may, from the known nature and structure of
the parts, draw particular conjectures about the particular offices of
them.
BOOK IX.
THE PHILOSOPHY OF BIOLOGY.
CHAPTER I.
ANALOGY OF BIOLOGY WITH OTHER SCIENCES.
I.
IN of after breeded to
N the History of the Sciences, after treating of
the Sciences of Classification, we proceeded to
what are there termed the Organical Sciences, including
in this term Physiology and Comparative Anatomy.
A peculiar feature in this group of sciences is that
they involve the notion of living things. The notion
of Life, however vague and obscure it may be in men's
minds, is apprehended as a peculiar Idea, not resolva-
ble into any other Ideas, such, for instance, as Matter
and Motion. The separation between living creatures
and inert matter, between organized and unorganized
beings, is conceived as a positive and insurmountable
barrier. The two classes of objects are considered as
of a distinct kind, produced and preserved by different
forces. Whether the Idea of Life is really thus origi-
nal and fundamental, and whether, if so, it be one
Idea only, or involve several, it must be the province
of true philosophy to determine. What we shall here
offer may be considered as an attempt to contribute
something to the determination of these questions;
but we shall perhaps be able to make it appear that
science is at present only in the course of its progress
towards a complete solution of such problems.
Since the main feature of those sciences of which
we have now to examine the philosophy is, that they
170
PHILOSOPHY OF BIOLOGY.
involve the Idea of Life, it would be desirable to have
them designated by a name expressive of that circum-
stance. The word Physiology, by which they have
most commonly been described, means the Science of
Nature; and though it would be easy to explain, by
reference to history, the train of thought by which the
word was latterly restricted to Living Nature, it is plain
that the name is, etymologically speaking, loose and
improper. The term Biology, which means exactly
what we wish to express, the Science of Life, has often
been used, and has of late become not uncommon
among good writers. I shall therefore venture to em-
ploy it, in most cases, rather than the word Physiology.
2. As I have already intimated, one main inquiry
belonging to the Philosophy of Biology, is concerning
the Fundamental Idea or Ideas which the science in-
volves. If we look back at the course and the results
of our disquisitions respecting other sciences in this
work, and assume, as we may philosophically do, that
there will be some general analogy between those
sciences and this, in their development and progress,
we shall be enabled to anticipate in some measure the
nature of the view which we shall now have to take.
We have seen that in other subjects the Fundamental
Ideas on which science depended, and the Conceptions
derived from these, were at first vague, obscure, and
confused;—that by gradual steps, by a constant union
of thought and observation, these conceptions become
more and more clear, more and more definite ;—and
that when they approached complete distinctness and
precision, there were made great positive discoveries
into which these conceptions entered; and thus the
new precision of thought was fixed and perpetuated
in some conspicuous and lasting truths.
Thus we
have seen how the first confused mechanical concep-
tions (Force, and the like,) were, from time to time,
growing clearer, down to the epoch of Newton ;-
how true conceptions of Genera and of wider classes,
gradually unfolded themselves among the botanists of
the sixteenth and seventeenth centuries;-how the
idea of Substance became steady enough to govern the
ANALOGY WITH OTHER SCIENCES.
171
theories of chemists only at the epoch of Lavoisier ;-
how the Idea of Polarity, although often used by phy-
sicists and chemists, is even now somewhat vague and
indistinct in the minds of the greater part of specula-
tors. In like manner we may expect to find that the
Idea of Life, if indeed that be the governing Idea of
the Science which treats of Living Things, will be
found to have been gradually approaching towards a
distinct and definite form among the physiologists of all
ages up to the present day. And if this be the case, it
may not be considered superfluous, with reference to
so interesting a subject, if we employ some space in
tracing historically the steps of this progress ;—the
changes by which the originally loose notion of Life, or
of Vital Powers, became more nearly an Idea suited to
the purposes of science.
3. But we may safely carry this analogy between
Biology and other sciences somewhat further. We
have seen, in other sciences, that while men in their
speculations were thus tending towards a certain pecu-
liar Idea, but before they as yet saw clearly that it was
peculiar and independent, they naturally and inevit-
ably clothed their speculations in conceptions borrowed
from some other extraneous idea. And the unsatis-
factoriness of all such attempts, and the necessary con-
sequence of this, a constant alteration and succession
of such inappropriate hypotheses, were indications and
aids of the progress which was going on towards a more
genuine form of the science. For instance, we have
seen that in chemistry, so long as men refused to re-
cognize a peculiar and distinct kind of power in the
Affinity which binds together the elements of bodies,
they framed to themselves a series of hypotheses, each
constructed according to the prevalent ideas of the
time, by which they tried to represent the relation of
the compound to the ingredients:-first, supposing
that the elements bestowed upon the whole qualities
resembling their own:-then giving up this supposi-
tion, and imagining that the properties of the body
depended upon the shape of the component particles;
—then, as their view expanded, assuming that it was
Uor M
172
PHILOSOPHY OF BIOLOGY.
not the shape, but the mechanical forces of the parti-
cles which gave the body its attributes;—and finally
acquiescing in, or rather reluctantly admitting, the
idea of Affinity, conceived as a peculiar power, differ-
ent not only from material contact, but from any me-
chanical or dynamical attraction.
Now we cannot but think it very natural, if we find
that the history of Biology offers a series of occurrences
of the same nature. The notions of Life in general,
or of any Vital Functions or Vital Forces in particular,
are obviously very loose and vague as they exist in the
minds of most men. The discrepancies and contro-
versies respecting the definitions of all such terms,
which are found in all works on physiology, afford us
abundant evidence that these notions are not, at least
not generally, apprehended with complete clearness
and steadiness. We shall therefore find approaches
and advances, intermediate steps, gradually leading
up to the greatest degree of distinctness which has yet
been attained. And in those stages of imperfect
apprehension in which the notions of Life and of Vital
Powers are still too loose and unformed to be applied
independently, we may expect to find them supported
and embodied by means of hypotheses borrowed from
other subjects, and thus, made so distinct and substan-
tial as to supply at least a temporary possibility of
scientific reasoning upon the laws of life.
4. For example, if we suppose that men begin to
speculate upon the properties of living things, not
acknowledging a peculiar Vital Power, but making
use successively of the knowledge supplied by the study
of other subjects, we may easily imagine a series of
hypotheses along which they would pass.
They would probably, first, in this as in other
sciences, have their thoughts occupied by vague and
mystical notions in which material and spiritual agency,
natural and supernatural events, were mixed together
without discrimination, and without any clear notion
at all. But as they acquired a more genuine percep-
tion of the nature of knowlege, they would naturally
try to explain vital motions and processes by means of
Marou
ANALOGY WITH OTHER SCIENCES.
173
such forces as they had learnt the existence of from
other sciences. They might first have a mechanical
hypothesis, in which the mechanical Forces of the solids
and fluids which compose organized bodies should be
referred to, as the most important influences in the
process of life. They might then attend to the actions
which the fluids exercise in virtue of their Affinity,
and might thus form a chemical theory. When they
had proved the insufficience of these hypotheses, bor-
rowed from the powers which matter exhibits in other
cases, they might think themselves authorized to
assume some peculiar power or agency, still material,
and thus they would have the hypothesis of a Vital
Fluid. And if they were driven to reject this, they
might think that there was no resource but to assume
an immaterial principle of life, and thus they would
arrive at the doctrine of an Animal Soul.
Now, through the cycle of hypotheses which we
have thus supposed, physiology has actually passed.
The conclusions to which the most philosophical minds
have been led by a survey of this progress is, that by
the failure of all these theories, men have exhausted
this path of inquiry, and shown that scientific truth is
to be sought in some other manner. But before I
proceed further to illustrate this result, it will be
proper, as I have already stated, to exhibit historically
the various hypotheses which I have described. In
doing this I shall principally follow the History of
Medicine of Sprengel. It is only by taking for my
guide a physiologist of acknowledged science and judg-
ment, that I can hope, on such a subject, to avoid
errours of detail. I proceed now to give in succession
an account of the Mystical, the Iatrochemical, the
Iatromathematical, and the Vital-Fluid Schools; and
finally of the Psychical School, who hold the Vital
Powers to be derived from the Soul (Psychè).
UorM
CHAPTER II.
SUCCESSIVE BIOLOGICAL HYPOTHESES.
SECT. I.-The Mystical School.
N order to abbreviate as much as can conveniently
IN to as as can
be done the historical view which I have now to
take, I shall altogether pass over the physiological
speculations of the ancients, and begin my survey with
the general revival of science in modern times.
We need not dwell long on the fantastical and un-
substantial doctrines concerning physiology which pre-
vailed in the sixteenth century, and which flowed in a
great measure from the fertile but ill-regulated imagi-
nations of the cultivators of Alchemy and Magic. One
of the prominent doctors of this school is the celebrated
Paracelsus, whose doctrines contained a combination
of biblical interpretations, visionary religious notions,
fanciful analogies, and bold experiments in practical
medicine. The opinion of a close but mystical resem-
blance of parts between the universe and the human
body, the Macrocosm and the Microcosm,-as these
two things, thus compared, were termed, had probably
come down from the Neoplatonists; it was adopted by
the Paracelsists', and connected with various astro-
logical dreams and cabbalistic riddles. A succession
of later Paracelsists², Rosicrucians, and other fanatics
of the same kind, continued into the seventeenth cen-
tury. Upon their notions was founded the pretension
of curing wounds by a sympathetic powder, which Sir
Kenelm Digby, among others, asserted; while animal
magnetism, and the transfer of diseases from one per-
son to another³, were maintained by others of this

1 Spr. iii. 456.
2 Ib. iv. 270.
3 Ib. iv. 276.
SUCCESSIVE BIOLOGICAL HYPOTHESES. 175
school. They held, too, the doctrines of astral bodies
corresponding to each terrestrial body; and of the sig-
natures of plants, that is, certain features in their ex-
ternal form by which their virtues might be known.
How little advantage or progress real physiology could
derive from speculations of this kind may be seen from
this, that their tendency was to obliterate the distinc-
tion between living and lifeless things: according to
Paracelsus, all things are alive, eat, drink, and excrete;
even minerals and fluids. According to him and his
school, besides material and immaterial beings, there
are elementary Spirits which hold an intermediate place,
Sylvans, Nymphs, Gnomes, Salamanders, &c. by whose
agency various processes of enchantment may be
achieved, and things apparently supernatural explained.
Thus this spiritualist scheme dealt with a world of its
own by means of fanciful inventions and mystical vi-
sions, instead of making any step in the study of nature.
Perhaps, however, one of the most fantastical of the
inventions of Paracelsus may be considered as indicat-
ing a perception of a peculiar character in the vital
powers. According to him, the business of digestion
is performed by a certain demon whom he calls Ar-
chaus, who has his abode in the stomach, and who, by
means of his alchemical processes, separates the nutri-
tive from the harmful part of our food, and makes it
capable of assimilation³. This fanciful notion was
afterwards adopted and expanded by Van Helmont.
According to him the stomach and spleen are both
under the direction of this Master-spirit, and these
two organs form a sort of Duumvirate in the body.
But though we may see in such writers occasional
gleams of physiological thought, the absence of definite
physical relations in the speculations thus promul-
gated was necessarily intolerable to men of sound
understanding and scientific tendencies. Such men
naturally took hold of that part of the phenomena of
life which could be most distinctly conceived, and
4 Spr. iii. 458. Parac. De Vita Rerum Naturalium, p. 889.
5 Ib. iii. 468.
6 Ib. iv. 303.
176
PHILOSOPHY OF BIOLOGY.
!
•
which could be apparently explained by means of the
sciences then cultivated; and this was the part which
appeared to be reducible to chemical conceptions and
doctrines. It will readily be supposed that the pro-
cesses of chemistry have a considerable bearing upon
physiological processes, and might, till their range was
limited by a sound investigation, be supposed to have
still more than they really had; and thus a Physiology
was formed which depended mainly upon Chemistry,
and the school which held this doctrine has been called
the Iatrochemical School.
SECT. II.-The Iatrochemical School.
That all physical properties, and therefore chemical
relations, have a material influence on physiological
results, was already recognized, though dimly, in the
Galenic doctrine of the four elementary qualities.'
But at the time of Paracelsus, chemical action was
more distinctly than before separated from other kinds
of physical action; and therefore a physiological doctrine,
founded upon chemistry, and freed from the extrava-
gance and mysticism of the Paracelsists, was a very
promising path of speculation. Andrew Libavius' of
Halle, in Saxony, Physician and Teacher in the Gym-
nasium at Koberg, is pointed out by Sprengel as the
person who began to cultivate chemistry, as distinct
from the theosophic fantasies of his predecessors; and
Angelus Sala of Vienna³, as his successor. The latter
has the laudable distinction of having rejected the pre-
valent conceits about a potable gold, a universal medi-
cine, and the like. In Germany already at the begin-
ning of the seventeenth century a peculiar chair of
Chymiatria was already created at Marpurg: and
many in various places pursued the same studies, till,
in the middle of the seventeenth century, we come to
Lemery¹º, the principal reformer of pharmaceutical
chemistry. But we are not here so much concerned
7 Spr. iii. 550.
9 Ib. iv. 283.
8 Ib. iv. 281.
10 Ib. iv. 291.
SUCCESSIVE BIOLOGICAL HYPOTHESES. 177
with the practical as with the theoretical parts of
Iatrochemistry; and hence we pass on to Sylvius" and
his system.
The opinion that chemistry had an important bear-
ing upon physiology did not, however, begin with Syl-
vius. Paracelsus, among his extravagant absurdities,
did some service to medicine by drawing attention to
this important truth. He used 12 chemical principles
for the explanation of particular diseases: most or all
diseases according to him, arise from the effervescence
of salts, from the combustion of sulphur, or from the
coagulation of mercury. His medicines were chemical
preparations; and it was 13 an undeniable advantage of
the Paracelsian doctrine that chemistry thus became
indispensable to the physician. We still retain a rem-
nant of the chemical nomenclature of Paracelsus in the
term tartar, denoting the stony concretion which forms
on the teeth¹. According to him there is a certain
substance, the basis of all diseases which arise from a
thickening of the juices and a collection of earthy
matter; and this substance he calls Tartarus, because
it 'burns like the fire of hell.' Helmont, the successor
of Paracelsus in many absurdities, also followed him in
the attempt to give a chemical account, however loose
and wild, of the functions of the human body; and is
by Sprengel considered, with all his extravagancies, as
a meritorious and important discoverer. The notion.
of the fermentation of fluids 15, and of the aërial pro-
duct thence resulting, to which he gave the name of
Gas, forms an important part of his doctrines; and of
the six digestions which he assumes, the first prepares
an acid, which is neutralized by the gall when it
reaches the duodenum, and this constitutes the second
digestion.
I have already, in the History of Chemistry 16, stated,
that the doctrine of the opposition of acid and alkali,
the great step which theoretical chemistry owes to
Sylvius, was first brought into view as a physiological
11 Spr. iv. 336.
12 Ib. iii. 472.
15 Vol. V. 315-
VOL. II.
13 Пb. iii. 482.
16 Hist. Ind. Sc. b. xiii. c. 2.
14 Tb. iii. 475.
N
178
PHILOSOPHY OF BIOLOGY.
tenet, although we had then to trace its consequences
in another science. The explanation of all the func-
tions of the animal system, both healthy and morbid,
by means of this and other chemical doctrines, and the
prescription of methods of cure founded upon such ex-
planations, form the scheme of the iatrochemical school ;
a school which almost engrossed the favour of European
physicians during the greater part of the seventeenth
century.
Sylvius taught medicine at Leyden, from the year
1658, with so much success, that Boerhaave alone sur-
passed him". His notions, although he piqued him-
self on their originality, were manifestly suggested in
no small degree (as all such supposed novelties are) by
the speculations of his predecessors, and the spirit of
the times. Like Helmont, he considers digestion as
consisting in a fermentation; but he states it more
definitely as the effervescence of an acid, supplied by
the saliva and the pancreatic juice, with the alkali of
the gall. By various other hypothetical processes, all
of a chemical nature, the blood becomes a collection of
various juices, which are the subjects of the specula-
tions of the iatrochemists, to the entire neglect of the
solid parts of the body. Diseases were accounted for
by a supposed prevalence of one or the other of the
acrid principles, the acid or the alkaline: and Sylvius "
was bold enough to found upon these hypotheses prac-
tical methods of cure, which were in the highest
degree mischievous.
19
The Sylvian doctrine was often combined with some
of the notions of the Cartesian system of philosophy;
but this mixture I shall not notice, since my present
object is to trace the history of a mere chemical
physiology as one of the unsuccessful attempts at a
philosophy of life. With various modifications, this
doctrine was diffused over Europe. It gave rise to
several controversies, which turned upon the questions
of the novelty of the doctrine, and the use of chemical
remedies to which it pointed, as well as upon its theo-
17 Spr. iv. 336.
18 Ib. 338.
19 Ib. iv. 345.
SUCCESSIVE BIOLOGICAL HYPOTHESES.
179
retical truth. We need not dwell long upon these
controversies, although they were carried on with no
small vehemence in their time. Thus the school of
Paris opposed all innovation, remained true to the
Galenic dogmatism, and declared itself earnestly against
all combination of chemistry with medicine; and even
against the chemical preparation of medicaments.
Guy Patin, a celebrated and learned professor of that
day, declares 20 that the chemists are no better than
forgers, and ought to be punished as such.
The use
of antimonial medicines was a main point of dispute
between the iatrochemists and their opponents; Patin
maintained that more men had been destroyed by
antimony than by the thirty years' war of Germany;
and endeavoured to substantiate this assertion by col-
lecting all such cases in his Martyrologium Antimonii.
It must have been a severe blow to Patin when 21 in
1666, the Doctors of the Faculty of Paris, assembled
by command of the parliament, declared, by a majority
of ninety-two voices, that the use of antimonial medi-
cines was allowable and laudable, and when all at-
tempts to set aside this decision failed.
Florentius Schuyl of Leyden sought to recommend
the iatrochemical doctrines, by maintaining that they
were to be found in the Hippocratic writings; nor
was it difficult to give a chemical interpretation of the
humoral pathology of the ancients. The Italian 22 phy-
sicians also, for the most part, took this line, and
attempted to show the agreement of the principles of
the ancient school of medicine with the new chemical
notions. This, indeed, is the usual manner in which
the diffusion of new theoretical ideas becomes uni-
versal.
The progress of the chemical school of medicine in
England 23 requires our more especial notice. Willis
was the most celebrated champion of this sect. He
assumed, but with modifications of his own, the three
Paracelsian principles, Salt, Sulphur, and Mercury;
considered digestion as the effect of an acid, and ex-
22 Ib. 368.
21 Ib. iv. 350.
20 Spr. 349-
23 Ib. 353.
N 2
180
PHILOSOPHY OF BIOLOGY.
plained other parts of the animal economy by distilla-
tion, fermentation, and the like. All diseases arise
from the want of the requisite ferment; and the physi-
cian, he says², may be compared to a vintner, since
both the one and the other have to take care that the
necessary fermentations go on, that no foreign matter
mixes itself with the wine of life, to interrupt or de-
range those operations. In the middle of the seven-
teenth century, medicine had reached a point in which
the life of the animal body was considered as merely a
chemical process; the wish to explain everything on
known principles left no recognized difference between
organized and unorganized bodies, and diseases were
The condi-
treated according to this delusive notion.
tion of chemistry itself during this period, though not
one of brilliant progress, was sufficiently stable and
flourishing to give a plausibility to any speculation
which was founded on chemical principles; and the
real influence of these principles in the animal frame
could not be denied.
The iatrochemists were at first resisted, as we have
seen, by the adherents of the ancient schools; they
were attacked on various grounds, and finally deposed
from their ascendancy by another sect, which we have
to speak of, as the iatromathematical, or mechanical
school. This sect was no less unsatisfactory and erro-
neous in its positive doctrines than the chemists had
been; for the animal frame is no more a mere ma-
chine than a mere laboratory: but it promoted the
cause of truth, by detecting and exposing the insuffici-
ent explanations and unproved assertions of the reign-
ing theory.
Boyle was one of the persons who first raised doubts
against the current chemical doctrines of his time, as
we have elsewhere noted; but his objections had no
peculiar physiological import. Herman Conring 25, the
most learned physician of his time, a contemporary
with Sylvius, took a view more pertinent to our pre-
sent object; for he not only rejected the alchemical
24 Spr. 354.
25 Ib. iv. 361.
SUCCESSIVE BIOLOGICAL HYPOTHESES.
181
and hermetical medicines, but taught expressly that
chemistry, in its then existing condition, was better
fitted to be of use in the practice of pharmacy, than in
the theories of physiology and pathology. He made the
important assertion, also, that chemical principles do
not pre-exist as such in the animal body; and that
there are higher powers which operate in the organic
world, and which do not depend on the form and mix-
ture of matter.
Attempts were made to prove the acid and alkaline
nature of the fluids of the human body by means of
experiments, as by John Viridet of Geneva 26, and by
Raimond Vieussens 27, the latter of whom maintained
that he had extracted an acid from the blood, and de-
tected a ferment in the stomach. In opposition to him,
Hecquet, a disciple of the iatromathematical school,
endeavoured to prove that digestion was performed, not
by means of fermentation, but by trituration. Hec-
quet's own opinions cannot be defended; but his objec-
tions to the chemical doctrines, and his assertion of
the difference of chemical and organical processes, are
evidences of just thought 28.
The most important opponents of the iatrochemical
school were Pitcairn in England, Bohn and Hoffman
in Germany, and Boerhaave in Holland. These emi-
nent physicians, about the end of the seventeenth
century, argued on the same grounds of observation,
that digestion is not fermentation, and that the Sylvian
accounts of the origin of diseases by means of acid and
alkali are false. The arguments and authority of these
and other persons finally gained an ascendancy in the
medical world, and soon after this period we may con-
sider the reign of the chemical school of physiology as
past. In fact, the attempts to prove its assertions ex-
perimentally were of the feeblest kind, and it had no
solid basis on which it could rest, so as to resist the
shock of the next hypothesis which the progress of
the physical sciences might impel against it.
We
may, therefore, now consider the opinion of the mere
28 Ib. 401.
27 Ib. 350, (1715).
26 Spr. iv. 329.
182
PHILOSOPHY OF BIOLOGY.
chemical nature of the vital processes as disproved,
and we proceed next to notice the history of another
unsuccessful essay to reduce vital actions to known
actions of another kind.
SECT. III.-The Iatromathematical School.
·
In the first Section of this chapter, we enumerated
the biological hypotheses which at first present them-
selves, as the mystical, the mechanical, the chemical.
We might have expected that they should occur to
men's minds in the order thus stated: and in fact they
did so; for the physiology of the ancient materialists,
as Democritus and Lucretius, is mechanical so far as it
is at all distinct in its views, and thus the mechanical
preceded the chemical doctrine. But in modern times,
the fluid or chemical physiology was developed before
the solid or mechanical: of which the reason appears
to have been this; that Mechanics and Chemistry
began to assume a scientific character about the same
time; and that of the two, Chemistry not only ap-
peared at first sight more applicable to the functions
of the body, because all the more rapid changes appear
to be connected with modifications of the fluids of the
animal system, but also, by its wider range of facts
and more indefinite principles, afforded a better tem-
porary refuge for the mind when perplexed by the
difficulties and mysteries which spring out of the spe-
culations concerning life. But if Chemistry was thus
at first a more inviting field for the physiologist, Me-
chanics soon became more attractive in virtue of the
splendid results obtained by the schools of Galileo and
Newton. And when the insufficiency of chemical
physiology was discovered by trial, as we have seen it
was, the hope naturally arose, that the mechanical
principles which had explained so many of the pheno-
mena of the external universe might also be found
applicable to the smaller world of material life;—that
the microcosm as well as the macrocosm might have
* its mechanical principles. From this hope sprung the
SUCCESSIVE BIOLOGICAL HYPOTHESES.
183
Iatromathematical School, or school of Mechanical
Physiologists.
We may, however, divide this school into two parts,
the Italian, and the Cartesio-Newtonian sect. The
former employed themselves in calculating and analys-
ing a number of the properties of the animal frame
which are undoubtedly mechanical; the latter, some-
what intoxicated by the supposed triumphs of the
corpuscular philosophy, endeavoured to extend these
to physiology, and for this purpose introduced into the
subject many arbitrary and baseless hypotheses. I will
very briefly mention some of the writers of both these
sects.
The main points to which the Italian or genuine
Mechanical Physiologists attended, were the applica-
tion of mechanical calculations to the force of the
muscles, and of hydraulical reasonings to the motion
of the fluids of the animal system. The success with
which Galileo and his disciples had pursued these
branches of mechanical philosophy, and the ascendancy
which they had obtained, first in Italy, and then in
other lands, made such speculations highly interesting.
Borelli may be considered as the first great name in
his line, and his book, De Motu Animalium, (Opus
Posthumum, Romæ, 1680,) is even now a very instruc-
tive treatise on the forces and action of the bones and
muscles. This, certainly one of the most valuable
portions of mechanical physiology, has not even yet
been so fully developed as it deserves, although John
Bernoulli and his son Daniel 30 applied to it the
resources of analysis, and Pemberton" in England,
pursued the same subject. Other of these mechanico-
physiological problems consisted in referring the pres-
sure of the blood and of the breath to hydrostatical
principles. In this manner Borelli was led to assert
that the muscles of the heart exert a force of 180,000
pounds. But a little later, Keill reduced this force
29 De Motu Musculorum.
31 Course of Physiology, 1773.
30 Act. Acad. Petrop.
32 Spr. iv. 110.
184
PHILOSOPHY OF BIOLOGY.
to a few ounces. Keill and others attempted to
determine, on similar principles, the velocity of the
blood; we need not notice the controversies which thus
arose, since there is not involved in them any peculiar
physiological principle.
The peculiar character of the iatromathematical
school, as an attempt at physiological theory, is more
manifest in its other section, which we have called the
Cartesio-Newtonian. The Cartesian system pretended
to account for the appearances and changes of bodies
by means of the size, figure, and motion of their minute
particles. And though this system in its progress to-
wards the intellectual empire of Europe was suddenly
overturned by the rise of the Newtonian philosophy,
these corpuscular doctrines rather gained than lost by
the revolution; for the Newtonian philosophy enlarged
the powers of the corpuscular hypothesis, by adding
the effects of the attractive and repulsive forces of
particles to those of their form and motion. By this
means, although Newton's discoveries did not in fact
augment the probability of the corpuscular hypothesis,
they so far increased its plausibility, that this hypo-
thesis found favour both with Newton himself and his
contemporaries, no less than it had done with the
Cartesians.
The attempt to apply this corpuscular hypothesis to
physiology was made by Des Cartes himself. The
general character of such speculations may easily be
guessed 34. The secretions are effected by the organs
operating after the manner of sieves. Round particles
pass through cylindrical tubes, pyramidal ones through
triangular pores, cubical particles through square aper-
tures, and thus different kinds of matter are separated.
Similar speculations were pursued by other mathema-
ticians: the various diameter of the vessels 35, their
curvatures, folds, and angles, were made subjects of
calculation. Bellini, Donzellini, Gulielmini, in Italy;
Perrault, Dodart, in France; Cole, Keill, Jurin, in
England, were the principal cultivators of such studies.
33 Spr. iv. 443.
3+ Ib. 329
35 Ib. 432.
SUCCESSIVE BIOLOGICAL HYPOTHESES. 185
In the earlier part of the eighteenth century, physio-
logical theorists considered it as almost self-evident
that their science required them to reason concerning
the size and shape of the particles of the fluids, the
diameter and form of the invisible vessels. Such was,
for instance, the opinion of Cheyne 36, who held that
acute fevers arise from the obstruction of the glands,
which occasions a more vehement motion of the blood.
Mead, the physician of the King, and the friend of
Newton, in like manner explained the effects of poisons
by hypotheses concerning the form of their particles ³7,
as we have already seen in speaking of chemistry.
•
>
It is not necessary for us to dwell longer on this
subject, or to point out the total insufficiency of the
mere mechanical physiology. The iatrochemists had
neglected the effect of the solids of the living frame;
the iatromathematicians attended only to these 38. And
even these were considered only as canals, as cords, as
levers, as lifeless machines. These reasoners never
looked for any powers of a higher order than the cohe-
sion, the resistance, the gravity, the attraction, which
operate in inert matter. If the chemical school assi-
milated the physician to a vintner or brewer, the
mechanical physiologists made him an hydraulic engi-
neer; and, in fact, several of the iatromathematicians
were at the same time teachers of engineering and of
medicine.
Several of the reasoners of this school combined che-
mical with their mechanical principles; but it would
throw no additional light upon the subject to give any
account of these, and I shall therefore go on to speak
of the next form of the attempt to explain the pro-
cesses of life.
SECT. IV.-The Vital-Fluid School.
I speak here, not of that opinion which assumes
some kind of fluid or ether as the means of communi-
36 Spr. iv. 223.
37 Mechanical Account of Poisons, 1702.
38 Spr. iv. 419.
186
PHILOSOPHY OF BIOLOGY.
cation along the nerves in particular, but of the hypo-
thesis that all the peculiar functions of life depend
upon some subtile ethereal substance diffused through
the frame;-not of a Nervous Fluid, but of a Vital
Fluid. Again, I distinguish this opinion from the
doctrine of an immaterial vital power or principle, an
Animal Soul, which will be the subject of the next
Section: nor is this distinction insignificant; for a
material element, however subtile, however much spirit-
ualized, must still act everywhere according to the
same laws; whereas we do not conceive an immaterial
spirit or soul to be subject to this necessity.
The iatromathematical school could explain to their
own satisfaction how motions, once begun, were trans-
ferred and modified; but in many organs of the living
frame there seemed to be a power of beginning motion,
which is beyond all mere mechanical action. This led
to the assumption of a Principle of a higher kind,
though still material. Such a Principle was asserted
by Frederick Hoffmann, who was born at Halle, in
166039, and became Professor of Medicine at the newly
established University there in 1694. According to
him, the reason of the greater activity of organized
bodies lies in the influence of a material substance of
extreme subtilty, volatility, and energy. This is, he
holds, no other than the Ether, which, diffused through
all nature, produces in plants the bud, the secretion
and motion of the juices, and is separated from the
blood and lodged in the brain of animals". From this,
acting through the nerves, must be derived all the
actions of the organs in the animal frame; for when
the influence of the nerve upon the muscle ceases,
muscular motion ceases also.
The mode of operation of this vital fluid was, how-
ever, by no means steadily apprehended by Hoffmann
and his followers. Its operations are so far mecha-
nical 12 that all effects are reduced to motion, yet they
42
39 Spr. v. 254.
40 Ib. v. 257.
41 De Differentia Organismi et Mechanismi, pp. 48, 67.
42 Spr. v. 262, 3.
SUCCESSIVE BIOLOGICAL HYPOTHESES.
187
+
43
cannot be explained according to known mechanical
laws. At one time the effects are said to take place
according to laws of a Higher Mechanics which are
still to be discovered 3. At another time, in complete
contradiction of the general spirit of the system, meta-
physical conceptions are introduced: each particle of
the vital fluid is said to have a determined idea of the
whole mechanism and organism", and according to this,
it forms the body and preserves it by its motion. By
means of this fluid the soul operates upon the body,
and the instincts and the passions have their source
in this material sensitive soul. This attribution of
ideas to the particles of the fluid is less unaccountable
when we recollect that something of the same kind is
admitted into Leibnitz's system, whose Monads have
also ideas.
Notwithstanding its inconsistencies, Hoffmann's
system was received with very general favour both in
Germany and in the rest of Europe; the more so, in-
asmuch as it fell in very well with the philosophy both
of Leibnitz and of Newton. The Newtonians were
generally inclined to identify the Vital Fluid with the
Ether, of which their master was so strongly disposed
to assume the existence and indeed he himself sug-
gested this identification.
When the discoveries made respecting Electricity in
the course of the eighteenth century had familiarized
men with the notion of a pervading subtile agent,
invisible, intangible, yet producing very powerful
effects in every part of nature, physiologists also
caught at the suggestion of such an agent, and tried,
by borrowing or imitating it, to aid the imperfection
of their notions of the vital powers. The Vital Prin-
ciple was imagined to be a substance of the same
kind, by some to be the same substance, with the
Electric Fluid. By its agency all these processes in
organized bodies were accounted for which cannot be
45
43 Hoffmann, Opp. Vol. v. p. 123.
44 De Diff. Organ. et Mechan. p. 81.
45 Prichard, On the Doctrine of a Vital Principle, p. 12.
188
PHILOSOPHY OF BIOLOGY.
explained by mechanical or chemical laws, as the se-
cretion of various matters (tears,. milk, bile, &c.) from
an homogeneous fluid, the blood; the production of
animal heat, digestion, and the like. According to
John Hunter, this attenuated substance pervaded the
blood itself, as well as the solid organic frame; and the
changes which take place in the blood which has
flowed out of the veins into a basin are explained by
saying that it is, for a time, till this vital fluid evapo-
rates, truly alive.
The notion of a Vital Fluid appears also to be
favourably looked upon by Cuvier; although with him
this doctrine is mainly put forwards in the form of a
Nervous Fluid. Yet in the following passage he ex-
tends the operation of such an agent to all the vital
functions 4: We have only to suppose that all the
medullary and nervous parts produce the Nervous
Agent, and that they alone conduct it; that is, that it
can only be transmitted by them, and that it is changed
or consumed by their actions. Then everything appears
simple. A detached portion of muscle preserves for
some time its irritability, on account of the portion of
nerve which always adheres to it. The sensibility and
the irritability reciprocally exhaust each other by their
exercise, because they change or consume the same
agent. All the interior motions of digestion, secre-
tion, excretion, participate in this exhaustion, or may
produce it. All local excitation of the nerves brings
thither more blood by augmenting the irritability of
the arteries, and the afflux of blood augments the
real sensibility by augmenting the production of the
nervous agent. Hence the pleasures of titillations,
the pains of inflammation. The particular sensations
increase in the same manner and by the same causes;
and the imagination exercises, (still by means of the
nerves,) upon the internal fibres of the arteries or
other parts, and through them on the sensations, an
action analogous to that of the will upon the voluntary
motions. As each exterior sense is exclusively disposed
46 Hist. Sc. Nat. depuis 1789, i. 214.
SUCCESSIVE BIOLOGICAL HYPOTHESES. 189
to admit the substances which it is to perceive, so each
interior organ, secretory or other, is also more excita-
ble by some one agent than by another: and hence
arises what has been called the proper sensibility or
proper life of the organs; and the influence of specifics
which, introduced into the general circulation, affect
only certain parts. In fine, if the nervous agent can-
not become sensible to us, the reason is that all sensa-
tion requires that this agent should be altered in some
way or other; and it cannot alter itself.
'Such is the summary idea which we may at present
form of the mutual and general working of the vital
powers in animals.'
47
Against the doctrine of a Vital Fluid as one uniform
material agent pervading the organic frame, an argu-
ment has been stated which points out extremely well
the philosophical objection to such an hypothesis *7. If
the Vital Principle be the same in all parts of the
body, how does it happen, it is asked, that the secre-
tions are so different? How do the particles in the
blood, separated from their old compounds and united
into new ones, under the same influence, give origin
to all the different fluids which are produced by the
glands? The liver secretes bile, the lacrymal gland,
tears, and so on. Is the Vital Principle different in
all these organs? To assert this, is to multiply nomi-
nal principles without limit, and without any advance
in the explanation of facts. Is the Vital Principle the
same, but its operation modified by the structure of
the organ? We have then two unknown causes, the
Vital Principle and the Organic Structure, to account
for the effect. By such a multiplication of hypotheses
nothing is gained. We may as well say at once, that
the structure of the organ, acting by laws yet unknown,
is the cause of the peculiar secretion. It is as easy to
imagine this structure acting to produce the whole
effect, as it is to imagine it modifying the activity of
another agent. Thus the hypothesis of the Vital Fluid
in this form explains nothing, and does not in any
47 Prichard, On a Vital Principle, p. 98.
190
PHILOSOPHY OF BIOLOGY.
་
*
way help onwards the progress of real biological know-
ledge.
The hypothesis of an immaterial vital principle must
now be considered.
SECT. V.—The Psychical School.
The doctrine of an Animal Soul as the principle
which makes the operations of organic different from
those of inorganic matter, is quite distinct from, and
we may say independent of, the doctrine of the soul as
the intelligent, moral, responsible part of man's nature.
It is the former doctrine alone of which we have here
to speak, and those who thus hold the existence of an
immaterial agent as the cause of the phenomena of
life, I term the Psychical School.
Such a view of the constitution of living things is
very ancient. For instance, Aristotle's Treatise On
the Soul,' goes entirely upon the supposition that the
Soul is the cause of motion, and he arrives at the con-
clusion that there are different parts in the Soul; the
nutritive or vegetative, the sensitive, and the rational 48.
But this doctrine is more instructive to us, when it
appears as the antagonist of other opinions concerning
the nature of life. In this form it comes before us as
promulgated by Stahl, whom we have already noticed
as one of the great discoverers in chemistry. Born in
the same year as Hoffmann, and appointed at his sug-
gestion professor at the same time in the same new
university of Halle, he soon published a rival physio-
logical theory. In a letter to Lucas Schröck, the pre-
sident of the Academy of Naturalists, he describes the
manner in which he was led to form a system for him-
self 49. Educated in the tenets of Sylvius and Willis,
according to which all diseases are derived from the
acidity of the fluids, Stahl, when a young student,
often wondered how these fluids, so liable to be pol-
luted and corrupted, are so wonderfully preserved
through innumerable external influences, and seem to
48 Arist. Hepì Yuxîs, ii. 2.
49 Spr. v. 303.
SUCCESSIVE BIOLOGICAL HYPOTHESES. 191
be far less affected by these than by age, constitution,
passion. No material cause could, he thought, pro-
duce such effects. No attention to mechanism or che-
mistry alone could teach us the true nature and laws
of organization.
So far as Stahl recognized the influence, in living
bodies, of something beyond the range of mechanics
and chemistry, there can be no doubt of the sound
philosophy of his views; but when he proceeds to
found a positive system of physiology, his tenets be-
come more precarious. The basis of his theory is this 50:
the body has, as body, no power to move itself, and
must always be put in motion by immaterial sub-
stances. All motion is a spiritual act³¹. The source
of all activity in the organic body, from which its pre-
servation, the permanency of its composition, and all
its other functions proceed, is an immaterial being,
which Stahl calls the Soul; because, as he says, when
the effects are so similar, he will not multiply powers
without necessity. Of this principle, he says, as the
Hippocratians said of Nature, that it does without
teaching what it ought to do 52,' and does it 'without
consideration 53, These ancient tenets Stahl interprets
in such a manner that even the involuntary motions
proceed from the soul, though without reflection or
clear consciousness. It is indeed evident, that there
are many customary motions and sensations which are
perfectly rational, yet not the objects of distinct con-
sciousness: and thus instinctive motions, and those of
which we are quite unconscious, may still be connected
with reason. The questions which in this view offer
themselves, as, how the soul passes from the mother to
the child, he dismisses as unprofitable 54. He considers
nutrition and secretion as the work of the soul. The
corpuscular theory and the doctrine of animal spirits
50 Spr. v. 308.
51 Ib. v. 314.
52 Stahl, περὶ φύσεως ἀπαίδευτου.
53 οὐκ ἐκ διανοίης.
problem. Harvey, On Generation
Exercise 27, p. 148, teaches, 'That
the egg is not the production of the
54 This was of course an obvious womb, but of the soul.'
192
PHILOSOPHY OF BIOLOGY.
are, he rightly observes, mere hypotheses, which are
arbitrary in their character, and only shift the difficulty.
For, if the animal spirits are not matter, how can they
explain the action of an immaterial substance on the
body; and if they are matter, how are they themselves
acted on?
This doctrine of the action of the soul on the body,
was accepted by many persons, especially by the iatro-
mathematicians, who could not but feel the insuffi-
ciency of their system without some such supplement:
such were Cheyne and Mead. In Germany, Stahl's
disciples in physiology were for the most part incon-
siderable persons 55. Several Englishmen who specu-
lated concerning the metaphysics as well as the phy-
siology of Sensation and Motion, inclined to this
psychical view, as Porterfield and Whytt. Among the
French, Boissier de Sauvages was the most zealous
defender of the Stahlian system. Actions, he says,
which belong to the preservation of life are determined
by a moral not a mechanical necessity. They proceed
from the soul, but cannot be controlled by it, as the
starting from fear, or the trembling at danger. Unzer,
a physician at Altona", was also a philosophical Stah-
lian 58
•
56
We need not dwell on the opposition which was
offered to this theory, first by Hoffmann, and after-
wards by Haller. The former of these had promul-
gated, as we have seen, the rival theory of a Nervous
Fluid, the latter was the principal asserter of the doc-
trine of Irritability, an important theory on which we
may afterwards have to touch. Haller's animosity
against the Stahlian hypothesis is a remarkable feature
in one who is in general so tolerant in his judgment
of opinions. His arguments are taken from the ab-
sence of the control of the will over the vital actions,
from the want of consciousness accompanying these
actions, from the uniformity of them in different con-
ditions of the mind, and from the small sensibility of
55 Spr. v. 339, &c.
57 A.D. 1799.
56 Ib. 358.
58 Spr. v. 360.
SUCCESSIVE BIOLOGICAL HYPOTHESES. 193
the heart which is the source of the vital actions.
These objections, and the too decided distinction
which Haller made between voluntary and involuntary
muscles, were very satisfactorily answered by Whytt
and Platner. In particular it was urged that the in-
stinctive actions of brutes are inexplicable by means of
mechanism, and may be compared with the necessary
vital actions of the human body. Neither kind are
accidental, neither kind are voluntary, both are per-
formed without reflection.
Without tracing further the progress of the Psychical
Doctrine, I shall borrow a few reflections upon it from
Sprengel :-
59
'When the opponents of the Stahlian system repeat
incessantly that the assumption of a psychical cause in
corporeal effects is a metaphysical speculation which
does not belong to medicine, they talk to no purpose.
The states of the soul are objects of our internal expe-
rience, and interest the physician too nearly to allow
him to neglect them. The innumerable unconscious
efforts of the soul, the powerful and daily effects of the
passions upon the body, too often put to confusion
those who would expel into the region of metaphysics
the dispositions of the mind. The connexion of our
knowledge of the soul, as gathered from experience,
with our knowledge of the human body, is far closer
than the mechanical and chemical physiologists sus-
pect.
'The strongest objection against the psychical sys-
tem, and one which has never been sufficiently answered
by any of its advocates, is the universality of organic
effects in the vegetable kingdom. The comparison of
the physiology of plants with the physiology of animals
puts the latter in its true light. Without absolutely
trifling with the word soul, we cannot possibly derive
from a soul the organic operations of vegetables. But
just as little can we, as some Stahlians have done, draw
a sharp line between plants and animals, and ascribe
the processes of the former to mere mechanism, while
VOL. II.
59 Spr. v. 383.
194
PHILOSOPHY OF BIOLOGY.
we derive the operations of the latter from an intellec-
tual principle. Not to mention that such a line is not
possible, the rise of the sap and the alteration of the
fluids of plants cannot be derived entirely from mate-
rial causes as their highest origin.'
Thus, I may add, this psychical theory, however diffi-
cult to defend in its detail, does in its generalities
express some important truths respecting the vital
powers. It not only, like the last theory, gives unity
to the living body, but it marks, more clearly than any
other theory, the wide interval which separates mecha-
nical and chemical from vital action, and fixes our
attention upon the new powers which the considera-
tion of life compels us to assume. It not only reminds
us that these powers are elevated above the known
laws of the material world, but also that they are
closely connected with the world of thought and feel-
ing, of will and reason; and thus it carries us, in a
manner in which none of the preceding theories have
done, to a true conception of a living, conscious, sen-
tient, active individual.
At the same time we cannot but allow that the life
of plants and of the lower orders of animals shows us
very clearly that, in order to arrive at any sound and
consistent knowledge respecting life, we must form
some conception of it from which all the higher attri-
butes which the term 'soul' involves, are utterly and
carefully excluded; and therefore we cannot but come
to the conclusion that the psychical school are right
mainly in this; that in ascribing the functions of life
to a soul, they mark strongly and justly the impossi-
bility of ascribing them to any known attributes of
body.
CHAPTER III.
ATTEMPTS TO ANALYSE THE IDEA OF LIFE.
1. Definitions of Life.-WE have seen in the pre-
ceding chapter that all attempts to obtain a distinct
conception of the nature of Life in general have ended
in failure, and produced nothing beyond a negative
result. And the conjecture may now naturally occur,
that the cause of this failure resides in an erroneous
mode of propounding to ourselves the problem. Instead
of contemplating Life as a single Idea, it may perhaps
be proper to separate it into several component no-
tions: instead of seeking for one cause of all vital
operations, it may be well to look at the separate vital
functions, and to seek their causes. When the view of
this possibility opens upon us, how shall we endeavour
to verify it, and to take advantage of it?
Let us, as one obvious course, take some of the
attempts which have been made to define Life, and let
us see whether they appear to offer to us any analysis
of the idea into component parts. Such definitions,
when they proceed from men of philosophical minds,
are the ultimate result of a long course of thought and
observation; and by no means deserve to be slighted
as arbitrary selections of conditions, or empty forms
of words.
2. Life has been defined by Stahl', 'The condi-
tion by which a body resists a natural tendency to
chemical changes, such as putrefaction.' In like man-
ner, M. von Humboldt defines living bodies to be
'those which, notwithstanding the constant operation
2
Treviranus, Biologie, p. 19. Stahlii, Their. Med. p. 254.
* Aphorismen aus d. Chem. Physiol. der Pflanzen, s. 1.
02.
196
PHILOSOPHY OF BIOLOGY.
of causes tending to change their form, are hindered
by a certain inward power from undergoing such
change.' The first of these definitions amounts only to
the assertion, that vital processes are not chemical; a
negative result, which we may accept as true, but
which is, as we have seen, a barren truth. The second
appears to be, in its import, identical with the first.
An inward principle can only be understood as distin-
guished from known external powers, such as mecha-
nical and chemical agencies. Or if, by an internal
principle, we mean such a principle as that cf which
we are conscious within ourselves, we ascribe a soul
to all living things: an hypothesis which we have seen
is not more effective than the former in promoting the
progress of biological science. Nearly the same criti-
cism applies to such definitions as that of Kant: that
'Life is an internal faculty producing change, motion,
and action.'
(
Other definitions refer us, not to some property
residing in the whole of an organized mass, but to the
connexion and relation of its parts. Thus M. von
Humboldt³ has given another definition of a living
body: that it is a whole whose parts, arbitrarily sepa-
rated, no longer resist chemical changes.' But this
additional assertion concerning the parts, adds nothing
of any value to the definition of the whole. And in
some of the lower kinds of plants and animals it is
hardly true as a fact.
3. Another definition* places the character of Life
in 'motions serviceable to the body moved.' To this it
has been objected³, that, on this definition, the earth
and the planets are living bodies. Perhaps it would
be more philosophical to object to the introduction of
so loose a notion as that of a property being serviceable
to a body. We might also add, that if we speak of all
vital functions as motions, we make an assumption quite
unauthorized, and probably false.
3 Versuche über die gereitzte Muskel und Nervenfäser, b. ii. p. 433.
4 Erhard, Röschlaub's Magazin der Heilkunde, b. i. st. 1. p. 69.
5 Treviranus, Biologie, p. 41.
ATTEMPTS TO ANALYSE THE IDEA OF LIFE. 197
Other definitions refer the idea of Life to the idea of
Organization. Life is the activity of matter according
to laws of organization.' We are then naturally led to
ask, What is Organization? In reply to this is given us
the Kantian definition of Organization, which I have
already quoted elsewhere', 'An organized product of
nature is that in which all the parts are mutually
ends and means". That this definition involves exact
fundamental ideas, and is capable of being made the
basis of sound knowledge, I shall hereafter endeavour
to show. But I may observe that such a definition
leads us somewhat further. If the parts of organized
bodies are known to be means to certain ends, this
must be known because they fulfil these ends, and pro-
duce certain effects by the operation of a certain cause
The question then recurs, what is the cause
which produces such effects as take place in organized
or living bodies? and this is identical with the problem
of which in the last chapter we traced the history, and
related the failure of physiologists in all attempts at its
solution.
or causes.
4. But what has been just said suggests to us
that it may be an improvement to put our problem in
another shape:—not to take for granted that the cause
of all vital processes is one, but to suppose that there
may be several separate causes at work in a living
body. If this be so, life is no longer one kind of ac-
tivity, but several. We have a number of operations
which are somehow bound together, and life is the
totality of all these: in short, life is not one Function,
but a System of Functions.
5. We are thus brought very near to the cele-
brated definition of life given by Bichat: 'Life is the
sum of the functions by which death is resisted.' But
upon the definition thus stated, we may venture to
observe;-first, that the introduction of the notion of
• Schmid, Physiologie, b. ii. p. 274.
7 Hist. Ind. Sc. b. xvii. c. viii. s. 2.
8 Kant, Urtheilskraft, p. 296.
9 Physiological Researches on Life and Death.
198
PHILOSOPHY OF BIOLOGY.
death in order to define the notion of life appears to be
unphilosophical. We may more naturally define death
with reference to life, as the cessation of life; or at
least we may consider life and death as correlative and
interdependent notions. Again, the word 'sum,' used
in the way in which it here occurs, appears to be likely
to convey an erroneous conception, as if the functions
here spoken of were simply added to each other, and
connected by co-existence. It is plain that our idea of
life involves more than this: the functions are all
clearly connected, and mutually depend on each other;
nutrition, circulation, locomotion, reproduction, each
has its influence upon all the others. These functions
not merely co-exist, but exist with many mutual rela-
tions and connexions; they are continued so as to
form, not merely a sum, but a system. And thus we
are led to modify Bichat's definition, and to say that
Life is the system of vital functions.
6. But it will be objected that by such a definition
we explain nothing: the notion of vital functions, it
may be said, involves the idea of life, and thus brings
us round again to our starting-point. Or if not, at
least it is as necessary to define Vital Functions as to
define Life itself, so that we have made little progress
in our task.
To this we reply, that if any one seeks, upon such
subjects, some ultimate and independent definition
from which he can, by mere reasoning, deduce a series
of conclusions, he seeks that which cannot be found.
In the Inductive Sciences, a Definition does not form
the basis of reasoning, but points out the course of in-
vestigation. The definition must include words; and
the meaning of these words must be sought in the pro-
gress and results of observations, as I have elsewhere
said ¹º. "The meaning of words is to be sought in the
progress of thought; the history of science is our dic-
tionary; the steps of scientific induction are our defi-
nitions.' It will appear, I think, that it is more easy
for us to form an idea of a separate Function of the
10
10 Hist. Ind. Sc. b. xiii. c. ix.
ATTEMPTS TO ANALYSE THE IDEA OF LIFE. 199
animal frame, as Nutrition or Reproduction, than to
comprehend Life in general under any single idea.
And when we say that Life is a system of Vital Func-
tions, we are of course directed to study these func-
tions separately, and (as in all other subjects of scien-
tific research) to endeavour to form of them such clear
and definite ideas as may enable us to discover their
laws.
7. The view to which we are thus led, of the most
promising mode of conducting the researches of Bio-
logy, is one which the greatest and most philosophical
physiologists of modern times have adopted. Thus
Cuvier considers this as the true office of physiology
at present. 'It belongs to modern times,' he says, 'to
form a just classification of the vital phenomena; the
task of the present time is to analyse the forces which
belong to each organic element, and upon the zeal and
activity which are given to this task, depends, accord-
ing to my judgment, the fortune of physiology "' This
classification of the phenomena of life involves, of
course, a distinction and arrangement of the vital
functions; and the investigation of the powers by
which these functions are carried on, is a natural
sequel to such a classification.
•
8. Classifications of Functions.—Attempts to clas-
sify the Vital Functions of man were made at an
early period, and have been repeated in great number
up to modern times. The task of classification is ex-
posed to the same difficulties, and governed by the
same conditions, in this as in other subjects. Here, as
in the case of other things, there may be many classi-
fications which are moderately good and natural, but
there is only one which is the best and the true natu-
ral system. Here, as in other cases, one classification
brings into view one set of relations; another, another;
and each may be valuable for its special purpose.
Here, as in other cases, the classes may be well con-
stituted, though the boundary lines which divide them
be somewhat indistinct, and the order doubtful. Here,
11 Hist. Sc. Nat. dep. 1789, i. 218.
200
PHILOSOPHY OF BIOLOGY.
i
T
as in other cases, we may have approached to the natu-
ral classification without having attained it; and here,
as in other cases, to define our classes is the last and
hardest of our problems.
9. The most ancient classification of the Functions
of living things 12, is the division of them into Vital,
Natural, and Animal. The Vital Functions are those
which cannot be interrupted without loss of life, as
Circulation, Respiration, and Nervous Communication.
The Natural Functions are those which without the
intervention of the will operate on their proper occa-
sions to preserve the bodies of animals; they are Di-
gestion, Absorption, Nutrition; to which was added
Generation. The Animal Functions are those which
involve perception and will, by which the animal is
distinguished from the vegetable; they are Sensibility,
Locomotion, and Voice.
The two great grounds of this division, the distinc-
tion of functions which operate continually, and those
which operate occasionally; and again, the distinction
of functions which involve sensation and voluntary
motion from those which do not; are truly of funda-
mental importance, and gave a real value to this classi-
fication. It was, however, liable to obvious objections:
namely, First, that the names of the classes were ill
chosen; for all the functions are natural, all are vital:
Second, that the lines of demarcation between the
classes are indefinite and ambiguous; Respiration is a
vital function, as being continually necessary to life;
but it is also a natural function, since it occurs in the
formation of the nutritive fluid, and an animal func-
tion, since it depends in part on the will. But these
objections were not fatal, for a classification may be
really sound and philosophical, though its boundary
lines are vague, and its nomenclature ill selected. The
division of the functions we have mentioned kept its
ground long; or was employed with a subdivision of
one class, so as to make them four; the vital, natural,
animal and sexual functions.
12 Dict. des Sciences Nat. art. Fonctions.
ATTEMPTS TO ANALYSE THE IDEA OF LIFE. 201
IO. I pass over many intermediate attempts to
classify the functions, and proceed to that of Bichat as
that which is, I believe, the one most generally as-
sented to in modern times. The leading principle in
the scheme of this celebrated physiologist is the dis-
tinction between organic and animal life. This sepa-
ration is nearly identical with the one just noticed
between the vital and animal functions; but Bichat,
by the contrasts which he pointed out between these
classes of functions, gave a decided prominence and
permanence to the distinction. The Organic Life,
which in animals is analogous to the life of vegetables,
and the Animal Life, which implies sensation and
voluntary motion, have each its system of organs.
The center of the animal life is the brain, of the organic
life, the heart. The former is carried on by a sym-
metrical, the latter, by an unsymmetrical system of
organs: the former produces intermitting, the latter
continuous actions: and, in addition to these, other
differences are pointed out. This distinction of the
two lives, being thus established, each is subdivided
into two orders of Functions. The Animal Functions
are passive, as Sensation: or active, as Locomotion and
Voice; again, the Organic Functions are those of Com-
position, which are concerned in taking matter into
the system; Digestion, Absorption, Respiration, Circu-
lation, Assimilation; and those of Decomposition, which
reject the materials when they have discharged their
office in the system; and these are again, Absorption,
Circulation, and Secretion. To these are added Calo-
rification, or the production of animal heat. It ap-
pears, from what has been said, that Absorption and
Circulation (and we may add Assimilation and Secre-
tion, which are difficult to separate,) belong alike to
the processes of composition and decomposition; nor in
truth, can we, with any rigour, separate the centri-
petal and centrifugal movements in that vortex which,
as we shall see, is an apt image of organic life.
Several objections have been made to this classifica-
tion and in particular, to the terms thus employed.
It has been asserted to be a perversion of language to
202
PHILOSOPHY OF BIOLOGY.
ascribe to animals two lives, and to call the higher
faculties in man, perception and volition, the animal
functions. But, as we have already said, when a clas-
sification is really good, such objections, which bear
only upon the mode in which it is presented, are by
no means fatal: and it is generally acknowledged by
all the most philosophical cultivators of biology, that
this arrangement of the functions is better suited to
the purposes of the science than those which pre-
ceded it.
II. But according to the principles which we have
already laid down, the solidity of such a classification
is to be verified by its serving as a useful guide in bio-
logical researches. If the arrangement which we have
explained be really founded in natural relations, it will
be found that in proportion as physiologists have
studied the separate functions above enumerated, their
ideas of these functions, and of the powers by which
they are carried on, have become more and more clear;
-have tended more and more to the character of exact
and rigorous science.
To examine how far this has been the case with
regard to all the separate functions, would be to at-
tempt to estimate the value of all the principal physio-
logical speculations of modern times; a task far too
vast and too arduous for any one to undertake who has
not devoted his life to such studies. But it may pro-
perly come within the compass of our present plan to
show how, with regard to the broader lines of the
above classification, there has been such a progress as
we have above described, from more loose and inaccu-
rate notions of some of the vital functions to more defi-
nite and precise ideas. This I shall attempt to point
out in one or two instances.
CHAPTER IV.
ATTEMPTS TO form Ideas of SEPARATE VITAL FORCES,
AND FIRST OF ASSIMILATION AND SECRETION.
I.
IT
SECT. I.—Course of Biological Research.
1
T is to be observed that at present I do not
speak of the
progress of our knowledge with
regard to the detail of the processes which take place
in the human body, but of the approach made to some
distinct Idea of the specially vital part of each process.
In the History of Physiology, it has been seen that
all the great discoveries made respecting the organs
and motions of the animal frame have been followed
by speculations and hypotheses connected with such
discoveries. The discovery of the circulation of the
blood led to theories of animal heat; the discovery of
the motion of the chyle led to theories of digestion ;
the close examination of the process of reproduction in
plants and animals led to theories of generation. In
all these cases, the discovery brought to light some
portion of the process which was mechanical or chemi-
cal, but it also, in each instance, served to show that
the process was something more than mechanical or
chemical. The theory attempted to explain the pro-
cess by the application of known causes; but there
always remained some part of it which must unavoid-
ably be referred to an unknown cause. But though
unknown, such a cause was not a hopeless object of
study. As the vital functions became better and better
understood, it was seen more and more clearly at what
precise points of the process it was necessary to assume
a peculiar vital energy, and what sort of properties
1 Hist. Ind. Sc. b. xvii.
204
PHILOSOPHY OF BIOLOGY.
:
this energy must be conceived to possess.
It was per-
ceived where, in what manner, in what degree, mecha-
nical and chemical agencies were modified, over-ruled,
or counteracted, by agencies which must be hyper-
mechanical and hyperchemical. And thus the disco-
veries made in anatomy by a laborious examination of
facts, pointed out the necessity of introducing new
ideas, in order that the facts might be intelligible.
Observation taught much; and among other things,
she taught that there was something which could not
be observed, but which must, if possible, be con-
ceived. I shall notice a few instances of this.
SECT. II.—Attempts to form a distinct Conception of
Assimilation and Secretion.
2.
The Ancients.-That plants and animals grow
by taking into their substance matter previously extra-
neous, is obvious to all: but as soon as we attempt to
conceive this process distinctly in detail, we find that
it involves no inconsiderable mystery. How does the
same food become blood and flesh, bone and hair?
Perhaps the earliest attempt to explain this mystery,
is that recorded by Lucretius as the opinion of
Anaxagoras, that food contains some bony, some fleshy
particles, some of blood, and so on. We might, on
this supposition, conceive that the mechanism of the
body appropriates each kind of particle to its suitable
place.
2
But it is easy to refute this essay at philosophizing
(as Lucretius refutes it) by remarking that we do not
find milk in grass, or blood in fruit, though such food
gives such products in cattle and in men. In opposi-
tion to this 'Homoiomereia,' the opinion that is forced
upon us by the facts is, that the process of nutrition is
not a selection merely, but an assimilation; the organ-
ized system does not find, but make, the additions to its
structure.
2 Lucr. i. 855. Nunc et Anaxagoræ scrutemur oμotoμépetav.
IDEAS OF SEPARATE VITAL FORCES. 205
3. Buffon. This notion of assimilation may be
variously expressed and illustrated; and all that we
can do here, in order to show the progress of thought,
is to adduce the speculations of those writers who have
been most successful in seizing and marking its pecu-
liar character. Buffon may be taken as an example of
the philosophy of his time on this subject.
6
The body
of the animal,' says he³, 'is a kind of interior mould,
in which the matter subservient to its increase is
modelled and assimilated to the whole, in such a way
that, without occasioning any change in the order and
proportion of the parts, there results an augmentation
in each part taken separately. This increase, this de-
velopment, if we would have a clear idea of it, how
can we obtain it, except by considering the body of
the animal, and each of the parts which is to be
developed, as so many interior moulds which only
receive the accessory matter in the order which results
from the position of all their parts? This develop-
ment cannot take place, as persons sometimes persuade
themselves, by an addition to the outside; on the con-
trary, it goes on by an intimate susception which
penetrates the mass; for, in the part thus developed,
the size increases in all parts proportionally, so that
the new matter must penetrate it in all its dimen-
sions: and it is quite necessary that this penetration
of substance must take place in a certain order, and
according to a certain measure; for if this were not
so, some parts would develope themselves more than
others. Now what can there be which shall prescribe
such a rule to the accessory matter except the interior
mould?'
To speak of a mould simply, would convey a coarse
mechanical notion, which could not be received as any
useful contribution to physiological speculation. But
this interior mould is, of course, to be understood
figuratively, not as an assemblage of cavities, but as a
collection of laws, shaping, directing, and modifying
the new matter; giving it not only form, but motion
3 Hist. Nat. b. i. c. iii.
206
PHILOSOPHY OF BIOLOGY.
and activity, such as belong to the parts of an organic
being.
4. It must be allowed, however, that even with
this explanation, the comparison is very loose and in-
sufficient. A mould may be permitted to mean a
collection of laws, but still it can convey no concep-
tion except that of laws regulated by relations of
space; and such a conception is very plainly quite in-
adequate to the purpose. What can we conceive of
the interior mould by which chyle is separated from
the aliments at the pores of the lacteals, or tears
secreted in the lacrymatory gland?
An additional objection to this mode of expression of
Buffon is, that it suggests to us only a single marked
change in the assimilated matter, not a continuous
series of changes. Yet the animal fluids and other
substances are, in fact, undergoing a constant series of
changes. Food becomes chyme, and chyme becomes
chyle; chyle is poured into the blood; from the blood
secretions take place, as the bile; the bile is poured
into the digestive canal, and a portion of the matter
previously introduced is rejected out of the system.
Here we must have a series of 'interior moulds;' and
these must impress matter at its ejection from the
organic system as well as at its reception. But, more-
over, it is probable that none of the above transfor-
mations are quite abrupt. Change is going on be-
tween the beginning and the end of each stage of the
nutritive circulation. To express the laws of this con-
tinuous change, the image of an interior mould is quite
unsuited. We must seek a better mode of conception.
5. Vegetable and animal nutrition is, as we have
said, a constant circulation. The matter so assumed is
not all retained: a perpetual subtraction accompanies a
perpetual addition. There is an excretion as well as an
intussusception. The matter which is assumed by the
living creature is retained only for a while, and is then
parted with. The individual is the same, but its parts
are in a perpetual flux: they come and go. For a time
the matter which belongs to the organic body is bound
to it by certain laws: but before it is thus bound, and
IDEAS OF SEPARATE VITAL FORCES. 207
after it is loose, this matter may circulate about the
universe in any other form.
Life consists in a per-
manent influence over a perpetually changing set of
particles.
Cuvier. This condition also has been happily ex-
pressed, by means of a comparison, by another great
naturalist. 'If,' says Cuvier, 'if, in order to obtain a
just idea of the essence of life, we consider it in the
beings where its effects are most simple, we shall soon
perceive that it consists in the faculty which belongs to
certain bodily combinations to continue during a deter-
minate time under a determinate form; constantly at-
tracting into their composition a part of the surround-
ing substances, and giving up in return some part of
their own substance.
'Life is thus a vortex, more or less rapid, more or
less complex, which has a constant direction, and which
always carries along its stream particles of the same
kinds; but in which the individual particles are con-
stantly entering in and departing out; so that the
form of the living body is more essential to it than its
matter.
'So long as this motion subsists, the body in which
it takes place is alive; it lives. When the motion stops
finally, the body dies. After death, the elements which
compose the body, given up to the ordinary chemical
affinities, soon separate, and the body which was alive
is dissolved.'
This notion of a vortex" which is permanent while
the matter which composes it constantly changes,—of
peculiar forces which act in this vortex so long as it
exists, and which give place to chemical forces when
4 Règne Animal, i. 11.
5 The definition of life given by
M. de Blainville appears to me not
to differ essentially from that of
Cuvier: 'Un corps vivant est une
sorte de foyer chimique où il-y-a à
tous momens apport de nouvelles
molecules et départ de molecules
anciennes; où la composition n'est
jamais fixe (si ce n'est d'un certain
nombre de parties veritablement
mortes ou en depôt), mais toujours
pour ainsi dire in nisu, d'où mouve-
ment plus ou moins lent et quelque-
fois chaleur.'-Principes d'Anat. 1822,
t. i. p. 16.
208
PHILOSOPHY OF BIOLOGY.
the circulatory motion ceases, appears to express
some of the leading conditions of the assimilative power
of living things in a simple and general manner, and
thus tends to give distinctness to the notion of this
vital function.
6. But we may observe that this notion of a Vortex
is still insufficient. Particles are not only taken into
the system and circulated through it for a time, but,
as we have seen, they are altered in character in a
manner to us unintelligible, both at their first admis-
sion into the system and at every period of their
progress through it. In the vortex each particle is
constantly transformed while it whirls.
It may be said, perhaps, that this transformation of
the kinds of matter may be conceived to be merely a
new arrangement of their particles, and that thus all
the changes which take place in the circulating sub-
stances are merely so many additional windings in the
course of the whirling current. But to say this, is to
take for granted the atomic hypothesis in its rudest
form. What right have we to assume that blood and
tears, bile and milk, consist of like particles of matter
differently arranged? What can arrangement, a mere
relation of space, do towards explaining such differ-
ences? Is not the insufficiency, the absurdity of such
an assumption proved by the whole course of science?
Are not even chemical changes, according to the best
views hitherto obtained, something more than a mere
new arrangement of particles? And are not vital as
much beyond chemical, as chemical are beyond geome-
trical modifications? It is not enough, then, to con-
ceive life as a vortex. The particles which are taken
into the organic frame do more than circulate there.
They are, at every point of their circulation, acted
upon by laws of an unknown kind, changing the nature
of the substance which they compose. Life is a vortex
in which vital forces act at every point of the stream :
it is not only a current of whirling matter, but a cycle
of recurring powers.
7. Matter and Form.-This image of a vortex is
closely connected with the representation of life offered
IDEAS OF SEPARATE VITAL FORCES. 209
us by writers of a very different school. In Schelling's
Lectures on Academic Study, he takes a survey of the
various branches of human knowledge, determining ac-
cording to his own principles the shape which each
science must necessarily assume. The peculiar cha-
racter of organization, according to him, is that the
matter is only an accident of the thing itself, and the
organization consists in Form alone. But this Form,
by its very opposition to Matter, ceases to be inde-
pendent of it, and is only ideally separable. In or-
ganization, therefore, substance and accident, matter
and form, are completely identical'. This notion, that
in organization the Form is essential and the Matter
accidental, or, in other words, that the Form is
perma-
nent and the Matter fluctuating and transitory, agrees,
if taken in the grossest sense of matter and form, with
Cuvier's image of a Vortex. In a whirlpool, or in a
waterfall, the form remains, the matter constantly
passes away and is renewed. But we have already
seen that in metaphysical speculations in which matter
and form are opposed, the word form is used in a far
more extensive sense than that which denotes a rela-
tion of space. It may indeed designate any change
which matter can undergo; and we may very allow-
ably say that food and blood are the same matter under
different forms. Hence if we assert that Life is a con-
stant Form of a circulating Matter, we express Cuvier's
notion in a mode free from the false suggestion which
'Vortex' conveys.
8
8. We may, however, still add something to this
account of life. The circulating parts of the system
not only circulate, but they form the non-circulating
parts. Or rather, there are no non-circulating parts:
all portions of the frame circulate more or less rapidly.
The food which we take circulates rapidly in the fluids,
more slowly in the flesh, still more slowly in the bones;
but in all these parts it is taken into the system,
6 Lect. xiii. p. 288.
7 I have not translated Schelling's words, but given their import as far
as I could.
8 Book i.
VOL. II.
P
210
PHILOSOPHY OF BIOLOGY.
retained there for some time, and finally replaced by
other matter. But while it remains in the body, it
exercises upon the other circulating parts the powers
by which their motion is produced. Nutriment forms
and supports the organs, and the organs carry fresh
nutriment to its destination. The peculiar forces of
the living body, and its peculiar structure, are thus
connected in an indescribable manner. The forces
produce the structure; the structure, again, is requisite
for the exertion of the forces. The Idea of an Organic
or Living Being includes this peculiar condition-that
its construction and powers are such, that it constantly
appropriates to itself new portions of substance which,
so appropriated, become indistinguishable parts of the
whole, and serve to carry on subsequently the same
functions by which they were assimilated. And thus
Organic Life is a constant Form of a circulating Mat-
ter, in which the Matter and the Form determine each
other by peculiar laws (that is, by Vital Forces).
SECT. III.—Attempts to conceive the forces of Assimi-
lation and Secretion.
9. I have already stated that in our attempts to
obtain clear and scientific Ideas of Vital Forces, we
have, in the first place, to seek to understand the
course of change and motion in each function, so as
to see at what points of the process peculiar causes
come into play; and next, to endeavour to obtain some
insight into the peculiar character and attributes of
these causes. Having spoken of the first part of this
mode of investigation in regard to the general nutri-
tion of organic bodies, I must now say a few words on
the second part.
The Forces here spoken of are Vital Forces. From
what has been said, we may see in some measure the
distinction between forces of this kind and mechanical
or chemical forces; the latter tend constantly to pro-
duce a final condition, after which there is no further
cause of change: mechanical forces tend to produce
equilibrium; chemical forces tend to produce composi-
IDEAS OF SEPARATE VITAL FORCES. 211
tion or decomposition; and this point once reached,
the matter in which these forces reside is altogether
inert. But an organic body tends to a constant mo-
tion, and the highest activity of organic forces shows
itself in continuous change. Again, in mechanical and
chemical forces, the force of any aggregate is the sum
of the forces of all the parts: the sum of the forces
corresponds to the sum of the matter. But in organic
bodies, the amount of effect does not depend on the
matter, but on the form: the particles lose their sepa-
rate energy, in order to share in that of the system;
they are not added, they are assimilated.
10. It is difficult to say whether anything has been
gained to science by the various attempts to assign a
fixed name to the vital force which is thus the imme-
diate cause of Assimilation. It has been called Organic
Attraction or Vital Attraction, Organic Affinity or
Vital Affinity, being thus compared with mechanical
Attraction or chemical Affinity. But, perhaps, as the
process is certainly neither mechanical nor chemical, it
is desirable to appropriate to it a peculiar name; and
the name Assimilation, or Organic Assimilation, by the
usage of good biological writers, is generally employed
for this purpose, and may be taken as the standard
name of this Vital Force. To illustrate this, I will
quote a passage from the excellent Elements of Physio-
logy of Professor Müller. 'In the process of nutrition
is exemplified the fundamental principle of organic
assimilation. Each elementary particle of an organ
attracts similar particles from the blood, and by the
changes it produces in them, causes them to participate
in the vital principle of the organ itself. Nerves take
up nervous substance, muscles, muscular substance:
even morbid structures have the assimilating power;
warts in the skin grow with their own peculiar struc-
ture; in an ulcer, the base and border are nourished in
a way conformable to the mode of action and secretion
determined by the disease.'
II. The Force of Organic Assimilation spoken of
in the last paragraph denotes peculiarly the force by
which each organ appropriates to itself a part of the
11
P 2
212
PHILOSOPHY OF BIOLOGY.
nutriment received into the system, and thus is main-
tained and augmented with the growth of the whole.
But the growth of the solid parts is only one portion of
the function of nutrition; besides this, we must con-
sider the motion and changes of the fluids, and must
ask what kind of forces may be conceived to produce
these. What are the powers by which chyle is ab-
sorbed from the food, by which bile is secreted from
the blood, by which the circulating motion of these and
all other fluids of the body are constantly maintained?
To the questions,-What are the forces by which ab-
sorption, secretion, and the vital motions, of fluids are
produced?—no satisfactory answer has been returned.
Yet still some steps have been made, which it may
be instructive to point out.
12. In Absorption it would appear that a part of the
agency is inorganic; for not only dead membranes, but
inorganic substances, absorb fluids, and even absorb
them with elective forces, according to the ingredients
of the fluid. A force which is of this kind, and which
has been termed Endosmose, has been found to pro-
duce very curious effects. When a membrane sepa-
rates two fluids, holding in solution different ingre-
dients, the fluids pass through the membrane in an
imperceptible manner, and mix or exchange their ele-
ments. The force which produces these effects is
capable of balancing a very considerable pressure. It
appears, moreover, to depend, at least among other
causes, upon attractions operating between the ele-
ments of the solids and the fluids, as well as between
the different fluids; and this force, though thus appa-
rently of a mechanical and chemical nature, probably
has considerable influence in vital phenomena.
13. But still, though Endosmose may account in
part for absorption in some cases, it is certain that
there is some other vital force at work in this process.
There must be, as Müller says, 'an organic attraction
of a kind hitherto unknown.' 'If absorption,' he
adds¹º, is to be explained in a manner analogous to
9 Physiology, p. 299.
10 Tb. p. 301.
IDEAS OF SEPARATE VITAL FORCES. 213
the laws of endosmose, it must be supposed that a che-
mical affinity, resulting from the vital process itself,
is exerted between the chyme in the intestines and
the chyle in the lacteals, by which the chyle is ena-
bled to attract the chyme without being itself attracted
by it. But such affinity or attraction would be of a
vital nature, since it does not exist after death.'
14. If the force of absorption be thus mysterious in
its nature, the force of Secretion is still more so. In
this case we have an organ filled with a fine net-work
of blood-vessels, and in the cavities of some gland, or
open part, we have a new fluid formed, of a kind alto-
gether different from the blood itself. It is easily
shown that this cannot be explained by any action of
pores or capillary tubes. But what conception can we
form of the forces by which such a change is produced?
Here, again, I shall borrow the expressions of Müller,
as presenting the last result of modern physiology. He
says", "The more probable supposition is, that by
virtue of imbibition, or the general organic porosity,
the fluid portion of the blood becomes diffused through
the tissue of the secreting organ; that the external
surface of the glandular canals exerts a chemical at-
traction on the elements of the fluid, infusing into
them at the same time a tendency to unite in new
combinations; and then repels them in a manner which
is certainly quite inexplicable, towards the inner sur-
face of the secreting membrane, or glandular canals.'
Although quite unsupported by facts,' he adds, this
theory of attraction and repulsion is not without its
analogy in physical phenomena; and it would appear
that very similar powers effect the elimination of the
fluid in secretion, and cause it to be taken up by
the lymphatics in absorption.' He elsewhere says ¹²,
Absorption seems to depend on an attraction the
nature of which is unknown, but of which the very
counterpart, as it were, takes place in secretion; the
fluids altered by the secreting action being repelled
towards the free side or open surface only of the
6
C
11 Physiology, p. 464.
12 Ib. p. 301.
6
12
214
PHILOSOPHY OF BIOLOGY.
secreting membranes, and then pressed forwards by the
successive portions of the fluids secreted.'
15. With regard to the forces which produce the
Motion of absorbed or secreted fluids along their des-
tined course, it may be seen, from the last quoted
sentence, that the same vital force which changes the
nature, also produces the movement of the substance.
The fluids are pressed forwards by the successive por-
tions absorbed or secreted. That this is the sole cause,
or at least a very powerful cause, of the motion of
the nutritive fluids in organic bodies, is easily shown
by experience. It is found 13 that the organs which
effect the ascent of the sap in trees during the spring
are the terminal parts of the roots; that the whole
force by which the sap is impelled upwards is the
vis a tergo, as it has been called, the force pushing
from behind, exerted in the roots. And thus the force
which produces this motion is exerted exactly at those
points where the organic body selects from the con-
tiguous mass those particles which it absorbs and
appropriates. And the same may most probably be
taken for the cause of the motion of the lymph and
chyle; at least, Müller says¹ that no other motive
power has been detected which impels those fluids
in their course.
Thus, though we must confess the Vital Force con-
cerned in Assimilation and Secretion to be unknown
in its nature, we still obtain a view of some of the at-
tributes which it involves. It has mechanical efficacy,
producing motions, often such as would require great
mechanical force. But it exerts at the same point
both an attraction and a repulsion, attracting matter
on one side, and repelling it on the other; and in
this circumstance it differs entirely from mechanical
forces. Again, it is not only mechanical but chemi-
cal, producing a complete change in the nature of the
substance on which it acts; to which we must add
that the changes produced by the vital forces are
such as, for the most part, our artificial chemistry can-
13 Müller, p. 300.
14 Ib. P. 254.
IDEAS OF SEPARATE VITAL FORCES.
215
not imitate. But, again, by the action of the vital
force at any point of an organ, not only are fluids
made to pass, and changed as they pass, but the organ
itself is maintained and strengthened, so as to continue
or to increase its operation: and thus the vital energy
supports its activity by its action, and is augmented
by being exerted.
We have thus endeavoured to obtain a view of some
of the peculiar characters which belong to the Force of
Organic Assimilation;-the Force by which life is kept
up, conceived in the most elementary form to which we
can reduce it by observation and contemplation. It ap-
pears that it is a force which not only produces motion
and chemical change, but also vitalizes the matter on
which it acts, giving to it the power of producing like
changes on other matter, and so on indefinitely. It
not only circulates the particles of matter, but puts
them in a stream of which the flow is development as
well as movement.
The force of Organic Assimilation being thus con-
ceived, it becomes instructive to compare it with the
force concerned in Generation, which we shall therefore
endeavour to do.
SECT. IV. Attempts to conceive the Process of
Generation.
In
16. At first sight the function of Nutrition appears
very different from the function of Generation.
the former case we have merely the existing organs
maintained or enlarged, and their action continued; in
the latter, we have a new individual produced and ex-
tricated from the parent. The term Reproduction has,
no doubt, been applied, by different writers, to both
these functions; to the processes by which an organ
when mutilated, is restored by the forces of the living
body, and to the process by which a new generation of
individuals is produced which may be considered as
taking the place of the old generation, as these are
gradually removed by death. But these are obviously
different senses of the word. In the latter case, the
216
PHILOSOPHY OF BIOLOGY.
term Reproduction is figuratively used; for the same
individuals are not reproduced; but the species is kept
up by the propagation of new individuals, as in nutri-
tion the organ is kept up by the assimilation of new
matter. To escape ambiguity, I shall avoid using the
term Reproduction in the sense of Propagation.
17. In Nutrition, as we have seen, the matter,
which from being at first extraneous, is appropriated
by the living system, and directed to the sustentation
of the organs, undergoes a series of changes of which
the detail eludes our observation and apprehension.
The nutriment which we receive contributes to the
growth of flesh and bone, viscera and organs of sense.
But we cannot trace in its gradual changes a visible
preparation for its final office. The portion of matter
which is destined to repair the waste of the eye or the
skin, is not found assuming a likeness to the parts of
the eye or the structure of the skin, as it comes near
the place where it is moulded into its ultimate form.
The new parts are insinuated among the old ones, in
an obscure and imperceptible matter. We can trace
their progress only by their effects. The organs are
nourished, and that is almost all we can learn: we
cannot discover how this is done. We cannot follow
nature through a series of manifest preparations and
processes to this result.
18. In Generation the case is quite different. The
young being is formed gradually and by a series of
distinguishable processes. It is included within the
parent before it is extruded, and approaches more or
less to the likeness of the parent before it is detached.
While it is still an embryo, it shares in the nutriment
which circulates through the system of the mother;
but its destination is already clear. While the new
and the old parts, in every other portion of the mother,
are undistinguishably mixed together, this new part,
the fœtus, is clearly distinct from the rest of the system,
and becomes rapidly more and more so, as the time
goes on.
And thus there is formed, not a new part,
but a new whole; it is not an organ which is kept up,
but an offspring which is prepared. The progeny is
IDEAS OF SEPARATE VITAL FORCES.
217.
included in the parent, and is gradually fitted to be
separated from it. The young is at first only the
development of a part of the organization of the
mother;—of a germ, an ovule. But it is not deve-
loped like other organs, retaining its general form. It
does not become merely a larger bud, a larger ovule;
it is entirely changed; it becomes from a bud-a
blossom, a flower, a fruit, a seed; from an ovule it be-
comes an egg, a chick, a bird; or it may be, a fœtus, a
child. The original rudiment is not merely nourished,
but unfolded and transformed through the most marked
and remote changes, gradually tending to the form of
the new individual.
19. But this is not all. The foetus is, as we have
said, a development of a portion of the mother's orga-
nization. But the foetus (supposing it female) is a
likeness of the mother. The mother, even before con-
ception, contains within herself the germs of her pro-
geny; the female fœtus, therefore, at a certain stage of
development, will contain also the germs of possible
progeny; and thus we may have the germs of future
generations, pre-existing and included successively
within one another. And this state of things, which
thus suggests itself to us as possible, is found to be
the case in facts which observation supplies. Ana-
tomists have traced ovules in the unborn fœtus, and
thus we have three generations included one within
another.
20. Supposing we were to stop here, the process of
propagation might appear to be altogether different
from that of nutrition. The latter, as we have seen,
may be in some measure illustrated by the image of a
vortex; the former has been represented by the image
of a series of germs, sheathed one within another suc-
cessively, and this without any limit. This view of
the subject has been termed the doctrine of the Pre-
existence of germs; and has been designated by Ger-
man writers by a term "Einschachtelungs-theorie'
descriptive of the successive sheathing of which I have
spoken. Imitating this term, we may call it the Theory
of successive inclusion. It has always had many
218
PHILOSOPHY OF BIOLOGY.
:
adherents; and has been, perhaps, up to the present
time, the most current opinion on the subject of genera-
tion. Cuvier inclines to this opinion 15. Fixed forms
perpetuating themselves by generation distinguish the
species of living things. These forms do not produce
themselves, do not change themselves. Life supposes
them to exist already; its flame can be lighted only in
organization previously prepared; and the most pro-
found meditations and the most delicate researches
terminate alike in the mystery of the pre-existence
of germs.'
21. Yet this doctrine is full of difficulty. It is, as
Cuvier says, a mysterious view of the subject;—so
mysterious, that it can hardly be accepted by us, who
seek distinct conceptions as the basis of our philosophy.
Can it be true, not only that the germ of the offspring
is originally included in the parent, but also the germs
of its progeny, and so on without limit:—so that
each fruitful individual contains in itself an infinite
collection of future possible individuals;—a reserve
of infinite succeeding generations? This is hard to
admit. Have we no alternative? What is the oppo-
site doctrine?
22. The opposite doctrine deserves at least some
notice. It extends, to the production of a new indivi-
dual, the conception of growth by nutrition. Accord
ing to this view, we suppose propagation to take place,
not as in the view just spoken of, by inclusion and ex-
trusion, but by assimilation and development;-not by
the material pre-existence of germs, but by the com-
munication of vital forces to new matter. This opinion
appears to be entertained by some of the most eminent
physiologists of the present time. Thus, Müller says,
'The organic force is also creative. The organic force
which resides in the whole, and on which the existence
of each part depends, has also the property of gene-
rating, from organic matter, the parts necessary to the
whole.' Life, he adds, is not merely a harmony of the
15 Règne Animal, p. 20.
IDEAS OF SEPARATE VITAL FORCES. 219
parts. On the contrary, the harmonious action of the
parts subsists only by the influence of a force pervading
all parts of the body. "This force exists before the
harmonizing parts, which are in fact formed by it
during the development of the embryo.' And again;
'The creative force exists in the germ, and creates in
it the essential force of the future animal. The germ
is potentially the whole animal: during the develop-
ment of the germ the parts which constitute the actual
whole are produced.'
23. In this view, we extend to the reproduction of
an individual the same conception of organic assimila-
tion which we have already arrived at, as the best
notion we can form of the force by which the repro-
duction and sustentation of parts takes place. And is
not such an extension really very consistent? If a
living thing can appropriate to itself extraneous mat-
ter, invest it with its own functions, and thus put it in
the stream of constant development, may we not con-
ceive the development of a new whole to take place in
this way as well as of a part? If the organized being
can infuse into new matter its vital forces, is there any
contradiction in supposing this infusion to take place
in the full measure which is requisite for the produc-
tion of a new individual? The force of organic assi-
milation is transferred to the very matter on which it
acts; it may be transferred so that the operation of
the forces produces not only an organ, but a system of
organs.
24. This identification of the forces which operate
in Nutrition and Generation may at first seem forced
and obscure, in consequence of the very strong appa-
rent differences of the two processes which we have
already noticed. But this defect in the doctrine is
remedied by the consideration of what may be consi-
dered as intermediate cases. It is not true that, in
the nutrition of special organs, the matter is always
conveyed to its ultimate destination without being on
its way moulded into the form which it is finally to
bear, as the embryo is moulded into the form of the
220
PHILOSOPHY OF BIOLOGY.
•
future individual. On the contrary, there are cases in
which the waste of the organs is supplied by the
growth of new ones, which are prepared and formed
before they are used, just as the offspring is prepared
and formed before it is separated from the parent.
This is the case with the teeth of many animals, and
especially with the teeth of animals of the crocodile
kind. Young teeth grow near the root of the old
ones, like buds on the stem of a plant; and as these
become fully developed, they take the place of the
parent tooth when that dies and is cast away. And
these new teeth in their turn are succeeded by others
which germinate from them. Several generations of
such teeth, it is said as many as four, have been de-
tected by anatomists, visibly existing at the same time;
just as several generations of germs of individuals
have been, as we already stated, observed included in
one another. But this case of the teeth appears to
show very strikingly how insufficient such observa-
tions are to establish the doctrine of successive inclu-
sion, or of the pre-existence of germs. Are we to
suppose that every crocodile's tooth includes in itself
the germs of an infinite number of possible teeth, as
in the theory of pre-existing germs every individual
includes an infinite number of individuals? If this be
true of teeth, we must suppose that organ to follow
laws entirely different from almost every other organ;
for no one would apply to the other organs in general
such a theory of reproduction. But if such a theory
be not maintained respecting the teeth, how can we
maintain the theory of the pre-existing germs of indi-
viduals, which has no recommendation except that
of accounting for exactly the same phenomena ?
It would seem, then, that we are, by the closest con-
sideration of the subject, led to conceive the forces by
which generation is produced, as forces which vitalize
certain portions of matter, and thus prepare them for
development according to organic forms; and thus the
conception of this Generative Force is identified with
the conception of the Force of Organic Assimilation, to
IDEAS OF SEPARATE VITAL FORCES. 221
which we were led by the consideration of the process
of nutrition.
I shall not attempt to give further distinctness and
fixity to this conception of one of the vital forces; but
I shall proceed to exemplify the same analysis of life
by some remarks upon another Vital Process, and the
Forces of which it exhibits the operation.
•
CHAPTER V.
ATTEMPTS TO FORM IDEAS OF SEPARATE VITAL
FORCES, continued.-VOLUNTARY MOTION.
I.
WE notionctions,
E formerly noticed the distinctions of organic
and animal functions, organic and animal
forces, as one of the most marked distinctions to
which physiologists have been led in their analysis of
the vital powers. I have now taken one of the former,
the organic class of functions, namely, Nutrition; and
have endeavoured to point out in some measure the
peculiar nature of the vital forces by which this func-
tion is carried on. It may serve to show the extent
and the difficulty of this subject, if, before quitting
it, I offer a few remarks suggested by a function
belonging to the other class, the animal functions.
This I shall briefly do with respect to Voluntary Mo-
tion.
2. In the History of Physiology, I have already
related the progress of the researches by which the
organs employed in voluntary motion became known
to anatomists. It was ascertained to the satisfaction
of all physiologists, that the immediate agents in such
motion are the muscles; that the muscles are in some
way contracted, when the nerves convey to them the
agency of the will; and that thus the limbs are moved.
It was ascertained, also, that the nerves convey sensa-
tions from the organs of sense inwards, so as to make
these sensations the object of the animal's conscious-
ness. In man and the higher animals, these impres-
sions upon the nerves are all conveyed to one internal
organ, the brain; and from this organ all impressions
of the will appear to proceed; and thus the brain is
IDEAS OF SEPARATE VITAL FORCES. 223
the center of animal life, towards which sensations
converge, and from which volitions diverge.
But this being the process, we are led to inquire
how far we can obtain any knowledge, or form any
conception, of the vital forces by means of which the
process is carried on. And here I have further stated
in the History', that the transfer of sensations and
volitions along the nerves was often represented as
consisting in the motion of a Nervous Fluid. I have
related that the hypothesis of such a fluid, conveying
its impressions either by motions of translation or of
vibration, was countenanced by many great names,
as Newton, Haller, and even Cuvier. But I have
ventured to express my doubt whether this hypothesis
can have much value: 'for,' I have said, 'this prin-
ciple cannot be mechanical, chemical, or physical, and
therefore cannot be better understood by embodying it
in a fluid. The difficulty we have in conceiving what
the force is, is not got rid of by explaining the machi-
nery by which it is transferred.'
3. I may add, that no succeeding biological re-
searches appear to have diminished the force of these
considerations. In modern times, attempts have re-
peatedly been made to identify the nervous fluid with
electricity or galvanism. But these attempts have not
been satisfactory or conclusive of the truth of such an
identity: and Professor Müller probably speaks the
judgment of the most judicious physiologists, when
he states it as his opinion, after examining the evi-
dence, That the vital actions of the nerves are not
attended with the development of any galvanic cur-
rents which our instruments can detect; and that the
laws of action of the nervous principle are totally dif-
ferent from those of electricity.
That the powers by which the nerves are the instru-
ments of sensation, and the muscles of motion, are
vital endowments, incapable of being expressed or ex-
plained by any comparison with mechanical, chemical,
and electrical forces, is the result which we should
1 Hist. Ind. Sc. b. xvii. c. v. S. 2.
2 Elem. Phys. p. 640.
224
PHILOSOPHY OF BIOLOGY.
7.
expect to find, judging from the whole analogy of sci-
ence; and which thus is confirmed by the history of
physiology up to the present time. We naturally, then,
turn to inquire whether such peculiar vital powers
have been brought into view with any distinctness
and clearness.
4. The property by which muscles, under proper
stimulation, contract and produce motion, has been
termed Irritability or Contractility; the property by
which nerves are susceptible of their appropriate im-
pressions has been termed Sensibility. A very few
words on each of these subjects must suffice.
Irritability. I have, in the History of Physiology,
noticed that Glisson, a Cambridge professor, distin-
guished the Irritation of muscles as a peculiar pro-
perty, different from any merely mechanical or physi-
cal action. I have mentioned, also, that he divides
Irritation into natural, vital, and animal; and points
out, though briefly, the graduated differences of Irrita-
bility in different organs. Although these opinions
did not at first attract much notice, about seventy
years afterwards attention was powerfully called to
this vital force, Irritability, by Haller. I shall borrow
Sprengel's reflections on this subject.
'Hitherto men had been led to see more and more
clearly that the cause of the bodily functions, the fun-
damental power of the animal frame, is not to be
sought in the mechanism, and still less in the mix-
ture of the parts. In this conviction, they had had re-
course partly to the quite supersensuous principle of
the Soul, partly to the half-material principle of the
Animal Spirits, in order to explain the bodily motions.
Glisson alone saw the necessity of assuming an Origi-
nal Power in the fibres, which, independent of the
influence of the animal spirits, should produce contrac-
tion in them. And Gorter first held that this Original
Power was not to be confined to the muscles, but to be
extended to all parts of the living body.
+
3 Hist. Ind. Sc. b. xvii. c. v.
IDEAS OF SEPARATE VITAL FORCES. 225
'But as yet the laws of this Power were not known,
nor had men come to an understanding whether it
were fully distinct from the elasticity of the parts,
or by what causes it was put in action. They had
neither instituted observations nor experiments which
established its relation to other assumed forces of the
body. There was still wanting a determination of the
peculiar seat of this power, and experiments to trace
its gradual differences in different parts of the body.
In addition to other causes, the necessity of the as-
sumption of such a power was felt the more, in conse-
quence of the prevalence of Leibnitz's doctrine of the
activity of matter; but it was an occult quality, and
remained so till Haller, by numerous experiments and
solid observations, placed in a clear light the peculiari-
ties of the powers of the animal body.'
5. Perhaps, however, Haller did more in the way
of determining experimentally the limits and details of
the application of this idea of Irritability as a peculiar
attribute, than in developing the Idea itself. In that
way his merits were great. As early as the year 1739,
he published his opinion upon Irritability as the cause
of muscular motion, which he promulgated again in
1743. But from the year 1747 he was more attentive
to the peculiarities of Irritability, and its difference
from the effect of the nerves. In the first edition of
his Physiology, which appeared in 1747, he distin-
guished three kinds of Force in muscles,-the Dead
Force, the Innate Force, and the Nervous Power. The
first is identical with the elastic force of dead matter,
and remains even after death. The innate force con-
tinues only a short time after death, and discloses
itself especially by alternate oscillations; the motions
which arise from this are much more lively than those
which arise from mere elasticity: they are not excited
by tension, nor by pressure, nor by any mechanical
alteration, but only by irritation. The nervous force
of the muscle is imparted to it from without by the
nerves; it preserves the irritability, which cannot long
subsist without the influence of the nervous force, but
is not identical with it.
VOL. II.
Q
226
PHILOSOPHY OF BIOLOGY.
In the year 1752, Haller laid before the Society of
Göttingen the result of one hundred and ninety expe-
riments; from which it appears to what parts of the
animal system Irritability and Nervous Power belong.
These I need not enumerate. He also investigated
with care its gradations in those parts which do possess
it. Thus the heart possesses it in the highest degree,
and other organs follow in their order.
6. Haller's doctrine was, that there resides in the
muscles a peculiar vital power by which they contract,
and that this power is distinct from the attributes of
the nerves. And this doctrine has been accepted by
the best physiologists of modern times. But this dis-
tinction of the irritability of the muscles from the
sensibility of the nerves became somewhat clearer by
giving to the former attribute the name of Contracti-
lity. This accordingly was done; it is, for example,
the phraseology used by Bichat. By speaking of
animal sensibility and animal contractility, the passive
and the active element of the processes of animal life
are clearly separated and opposed to each other. The
sensations which we feel, and the muscular action
which we exert, may be closely and inseparably con-
nected, yet still they are clearly distinguishable. We
can easily in our apprehension separate the titillation
felt in the nose on taking snuff, from the action of the
muscles in sneezing; or the perception of an object
falling towards the eye, from the exertion which shuts
the eye-lid; although in these cases the passive and
active part of the process are almost or quite inse-
parable in fact. And this clear separation of the
active from the passive power is something, it would
seem, peculiar to the Animal Vital Powers; it is a
character by which they differ, not only from mecha-
nical, chemical, and all other merely physical forces,
but even from Organic Vital Powers.
7. But this difference between the Animal and the
Organic Vital Powers requires to be further insisted
upon, for it appears to have been overlooked or denied
by very eminent physiologists. For instance, Bichat
classifies the Vital Powers as Animal Sensibility, Ani-
IDEAS OF SEPARATE VITAL FORCES. 227
mal Contractility, Organic Sensibility, Organic Con-
tractility.
Now the view which suggests itself to us, in agree-
ment with what has been said, is this:—that though
Animal Sensibility and Animal Contractility are
clearly and certainly distinct, Organic Sensibility and
Organic Contractility are neither separable in fact nor
in our conception, but together make up a single Vital
Power. That they are not separable in fact is, indeed,
acknowledged by Bichat himself. "The organic con-
tractility,' he says, 'can never be separated from the
sensibility of the same kind; the reaction of the ex-
creting tubes is immediately connected with the action
which the secreted fluids exercise upon them: the
contraction of the heart must necessarily succeed the
influx of the blood into it.' It is not wonderful, there-
fore, that it should have happened, as he complains,
that 'authors have by no means separated these two
things, either in their consideration or in language.'
We cannot avoid asking, Are Organic Sensibility and
Organic Contractility really anything more than two
different aspects of the same thing, like action and re-
action in mechanics, which are only two ways of con-
sidering the action which takes place at a point; or
like the positive and negative electricities, which, as
we have seen, always co-exist and correspond to each
other?
8. But we may observe, moreover, that Bichat, by
his use of the term Contractility, includes in it powers
to which it cannot with any propriety be applied.
Why should we suppose that the vital powers of ab-
sorption, secretion, assimilation, are of such a nature
that the name contractility may be employed to de-
scribe them? We have seen, in the last chapter, that
the most careful study of these powers leads us to
conceive them in a manner altogether removed from
any notion of contraction. Is it not then an abuse of
language which cannot possibly lead to anything but
▲ Life and Death, p. 94.
Q 2
228
PHILOSOPHY OF BIOLOGY,
6
confusion, to write thus: "The insensible organic con-
tractility is that, by virtue of which the excreting
tubes react upon their respective fluids, the secreting
organs upon the blood which flows into them, the parts
where nutrition is performed upon the nutritive juices,
and the lymphatics upon the substances which ex-
cite their open extremities'? In the same manner he
ascribes to the peculiar sensibility of each organ the
peculiarity of its products and operations. An in-
creased absorption is produced by an increased sus-
ceptibility of the 'absorbent orifices.' And thus, in
this view, each organic power may be contemplated
either as sensibility or as contractility, and may be
supposed to be rendered more intense by magnifying
either of these its aspects; although, in fact, neither
can be conceived to be increased without an exactly
commensurate increase of the other.
9. This opinion, unfounded as it thus appears to
be, that all the different organic vital powers are
merely different kinds of Contractility or Excitability,
was connected with the doctrines of Brown and his
followers, which were so celebrated in the last century,
that all diseases arise from increase or from diminution
of the Vital Force. The considerations which have
already offered themselves would lead us to assent to
the judgment which Cuvier has pronounced upon this
system. The theory of excitation,' he says, 'so cele-
brated in these later times by its influence upon patho-
logy and therapeutick, is at bottom only a modification
of that, in which, including under a common name
Sensibility and Irritability,' and we may add, applying
this name to all the Vital Powers, 'the speculator
takes refuge in an abstraction so wide, that if, by
it, he simplifies medicine, he by it annihilates all posi-
tive physiology'.
IO.
The separation of the nervous influence and
the muscular irritability, although it has led to many
highly instructive speculations, is not without its diffi-
5 Life and Death, p. 95.
6 Ib. p. 90.
7 Hist. des Sc. Nat. depuis 1789, i. 219.
IDEAS OF SEPARATE VITAL FORCES. 229
culties, when viewed with reference to the Idea of
Vital Power. If the irritability of each muscle reside
in the muscle itself, how does it differ from a mere
mechanical force, as elasticity? But, in point of fact,
it is certain that the muscular irritability of the ani-
mal body is not an attribute of the muscle itself inde-
pendent of its connexion with the system. No muscle,
or other part, removed from the body, long preserves
its irritability. This power cannot subsist permanently,
except in connexion with an organic whole. This
condition peculiarly constitutes irritability a living
force: and this condition would be satisfied by con-
sidering the force as derived from the nervous system;
but it appears that though the nervous system has the
most important influence upon all vital actions, the
muscular irritability must needs be considered as some-
thing distinct. And thus the Irritability or Contrac-
tility of the muscle is a peculiar endowment of the
texture, but it is at the same time an endowment
which can only co-exist with life; it is, in short, a
peculiar Vital Power.
II. This necessity of the union of the muscle with
the whole nervous system, in order that it may possess
irritability, was the meaning of the true part of Stahl's
psychical doctrine; and the reason why he and his ad-
herents persisted in asserting the power of the soul
even over involuntary motions. This doctrine was
the source of much controversy in later times.
'But,' says Cuvier, 'this opposition of opinion may
be reconciled by the intimate union of the nervous
substance with the fibre and the other contractile or-
ganic elements, and by their reciprocal action ;—-doc-
trines which had been presented with so much proba-
bility by physiologists of the Scotch school, but which
were elevated above the rank of hypotheses only by the
observations of more recent times.
'The fibre does not contract by itself, but by the
influence of the nervous filaments, which are always
united with it. The change which produces the con-
8 Hist. des Sc. Nat. depuis 1789, i. 213.
230
PHILOSOPHY OF BIOLOGY.
traction cannot take place without the concurrence of
both these substances; and it is further necessary that
it should be occasioned each time by an exterior cause,
by a stimulant.
The Will is one of these stimulants; but it only
excites the Irritability, it does not constitute it; for in
the case of persons paralytic from apoplexy, the Irrita-
bility remains, though the power of the Will over it is
gone. Thus irritability depends in part on the nerve,
but not on the sensibility: this last is another pro-
perty, still more admirable and occult than the irri-
tability; but it is only one among several functions
of the nervous system. It would be an abuse of words
to extend this denomination to functions unaccom-
panied by perception.'
9
12. Supposing, then, that Contractility is esta-
blished as a peculiar Vital Power residing in the
muscles, we may ask whether we can trace with any
further exactness the seat and nature of this power.
It would be unsuitable to the nature of the present
work to dwell upon the anatomical discussions bear-
ing upon this point. I will only remark that some
anatomists maintain that muscles are contracted by
those fibres assuming a zigzag form, which at first were
straight. Others (Professor Owen and Dr. A. Thomp-
son) doubt the accuracy of this observation; and con-
ceive that the muscular fibre becomes shorter and
thicker, but does not deviate from a right line. We
may remark that the latter kind of action appears to
be more elementary in its nature. We can, as a matter
of geometry, conceive a straight line thrown into a
zigzag shape by muscular contractions taking place be-
tween remote parts of it; but it is difficult to conceive
by what elementary mode of action a straight fibre could
bend itself at certain points, and at certain points only;
since the elementary force must act at every point of
the fibre, and not at certain selected points.
13. A circumstance which remarkably marks the
difference between the vital force of Contractility, in-
9 Muller, Elem. Phys. p. 887.
IDEAS OF SEPARATE VITAL FORCES. 231
10
herent in muscles, and any merely dead or mechanical
force, is this; that in assuming their contractile state,
muscles exert a tension which they could not them-
selves support or convey if not strengthened by their
vital irritability. They are capable of raising weights
by their exertion, which will tear them asunder when
the power of contraction is lost by death. This has
induced Cuvier and other physiologists' to believe
that in the moment of action, the particles that com-
pose a fibre, not only approach towards each other
longitudinally, but that their cohesive attraction be-
comes instantaneously much greater than it was be-
fore: for without such an increase of cohesive force,
the tendency to shorten could not, as it would appear,
prevent the fibre from being torn.' We see here the
difficulty, or rather the impossibility, of conceiving
muscular contractility as a mere mechanical force; and
perhaps there is little hope of any advantage by calling
in the aid of chemical hypothesis to solve the mecha-
nical difficulty. Cuvier conjectures that a sudden
change in the chemical composition may thus so
quickly and powerfully augment the cohesion. But
we may ask, are not a chemical synthesis and ana-
lysis, suddenly performed by a mere act of the will, as
difficult to conceive as a sudden increase and decrease
of mechanical power directly produced by the same
cause?
14. Sensibility. The nerves are the organs and
channels of Sensibility. By means of them we receive
our sensations, whether of mere pleasure and pain, or
of qualities which we ascribe to external objects, as a
bitter taste, a sweet odour, a shrill sound, a red colour,
a hard or a hot feeling of touch. Some of these sensa-
tions are but obscurely the objects of our conscious-
ness; as for example the feeling which our feet have of
the ground, or the sight which our eyes have of neigh-
bouring objects, when we walk in a reverie. In these
cases the sensations, though obscure, exist; for they
10 Prichard, Vital Prin. p. 126.
232
PHILOSOPHY OF BIOLOGY.
serve to balance and guide us as we walk. In other
cases, our sensations are distinctly and directly the ob-
jects of our attention.
But our Sensations, as we have already said, we
ascribe as Qualities to external objects. By our senses
we perceive objects, and thus our sensations become
perceptions. We have not only the sensation of round,
purple, and green, repeated and varied, but the percep-
tion of a bunch of grapes partly ripe and partly unripe.
We have not only sensations of noise and of variously-
coloured specks rapidly changing their places, but we
have perceptions, by sound and sight, of a stone roll-
ing down the hill and crushing the shrubs in its path.
We scarcely ever dwell upon our Sensations; our
thoughts are employed upon Objects. We regard the
impressions upon our nerves, not for what they are,
but for what they tell us.
But in what Language do the impressions upon the
nerves thus speak to us of an external world,—of the
forms and qualities and actions of objects? How is it
that by the aid of our nervous system we become ac-
quainted not only with impressions but with things;
that we learn not only the relation of objects to us,
but to one another?
15. It has been shown at some length in the pre-
vious Books, that the mode in which Sensations are
connected in our minds so as to convey to us the
knowledge of Objects and their Relations, is by being
contemplated with reference to Ideas. Our Sensations,
connected by the Idea of Space, become Figures; con-
nected by the Idea of Time, they become Causes and
Effects; connected by the Idea of Resemblance, they
become Individuals and Kinds; connected by the Idea
of Organization, they become Living Things. It has
been shown that without these Ideas there can be
no connexion among our sensations, and therefore no
perception of Figure, Action, Kind, or in short, of
bodies under any aspect whatever. Sensations are the
rude Matter of our perceptions; and are nothing, ex-
cept so far as they have Form given them by Ideas.
IDEAS OF SEPARATE VITAL FORCES. 233
But thus moulded by our Ideas, Sensation becomes
the source of an endless store of important Knowledge
of every possible kind.
16. But one of the most obvious uses of our per-
ceptions and our knowledge is to direct our Actions.
It is suitable to the condition of our being that when
we perceive a bunch of grapes, we should be able
to pluck and eat the ripe ones; that when we per-
ceive a stone rushing down the side of a hill, we
should be able to move so as to avoid it. And this
must be done by moving our limbs; in short, by the
use of our muscles. And thus Sensation leads, not
directly, but through the medium of Ideas, to mus-
cular Contraction. I say that sensation and Muscular
action are in such cases connected through the medium
of Ideas. For when we proceed to pluck the grape
which we see, the sensation does not determine the
motion of the hand by any necessary geometrical or
mechanical conditions, as an impression made upon a
machine determines its motions; but the perception
leads us to stretch forth the hand to that part of space,
wherever it is, where we know that the grape is; and
this, not in any determinate path, but, it may be,
avoiding or removing intervening obstacles, which we
also perceive. There is in every such case a connex-
ion between the sensation and the resulting action, not
of a material but of a mental kind. The cause and
the effect are bound together, not by physical but by
intellectual ties.
17. And thus in such cases, between the two vital
operations, Sensation and Muscular Action, there inter-
venes, as an intermediate step, Perception or Know-
ledge, which is not merely vital but ideal. But this
is not all; there is still another mental part of the
process which may be readily distinguished from that
which we have described. An act of the Will, a
Volition, is that, in the Mind, which immediately de-
termines the action of the Muscles of the Body.
thus Will intervenes between Knowledge and Action;
and the cycle of operations which take place when
animals act with reference to external objects is
And
234
PHILOSOPHY OF BIOLOGY.
this:-Sensation, Perception, Volition, Muscular Con-
traction.
18. To attempt further to analyse the mental part
of this cycle does not belong to the present part of our
work. But we may remark here, as we have already
remarked in the History", how irresistibly we are led
by physiological researches into the domain of thought
and mind. We pass from the body to the soul, from
physics to metaphysics; from biology to psychology;
from things to persons; from nouns to pronouns. I have
there noticed the manner in which Cuvier expresses
this transition by the introduction of the pronoun:
'The impression of external objects upon the ME, the
production of a sensation, of an image, is a mystery
impenetrable to our thoughts.'
19. But to return to the merely biological part of
our speculations. We have arrived, it will be perceived,
at this result: that in animal actions there intervenes
between the two terms of Sensation and Muscular
Contraction, an intermediate process; which may be
described as a communication to and from a Center. The
Center is the seat of the sentient and volent faculties,
and is of a hyperphysical nature. But the existence of
such a Center as a necessary element in the functions of
the animal life is a truth which is important in biology.
This indeed may be taken as the peculiar character of
animal, as distinguished from merely organic powers.
Accordingly, it is so stated by Bichat. For although
he superfluously, as I have tried to show, introduces
into his list of vital powers an organic sensibility, he
still draws the distinction of which I have spoken;
' in the animal life, Sensibility is the faculty of receiving
an Impression plus that of referring it to a common
Center 12,
20. But since Sensibility and Contractility are thus
connected by reference to a common Center, we may
ask, before quitting the subject, what are the different
forms which this reference assumes? Is the connexion
11 Hist. Ind. Sc. b. xvii. c. v. s. 2.
12 Life and Death, p. 84.
IDEAS OF SEPARATE VITAL FORCES. 235
always attended by the distinct steps of Knowledge and
Will,-by a clear act of consciousness, as in the case
which we have taken, of plucking a grape; or may
these steps become obscure, or vanish altogether?
We need not further illustrate the conscious con-
nexion. Such actions as we have described are called
voluntary actions. In extreme cases, the mental part
of the process is obvious enough. But we may gradu-
ally pass from these to cases in which the mental ope-
ration is more and more obscure.
In walking, in speaking, in eating, in breathing, our
muscular exertions are directed by our sensations and
perceptions: yet in such processes, how dimly are we
conscious of perceptive and directive power! How the
mind should be able to exercise such a power, and yet
should be scarcely or not at all conscious of its exercise,
is a very curious problem. But in all or in most of the
instances just mentioned, the solution of this problem
appears to depend upon psychological rather than bio-
logical principles, and therefore does not belong to this
place.
21. But in cases at the other extreme (unconscious
actions) the mental part of the operation vanishes al-
together. In many animals, even after decapitation,
the limbs shrink when irritated. The motions of the
iris are determined by the influence of light on our
eyes, without our being aware of the motions. Here
Sensations produce Motions, but with no trace of in-
tervening Perception or Will. The Sensation appears
to be reflected back from the central element of animal
life, in the form of a Muscular Contraction; but in
this case the Sensation is not modified or regulated by
any Idea. These reflected motions have no reference
to relations of space or force among surrounding ob-
jects. They are blind and involuntary, like the move-
ments of convulsion, depending for direction and amount
only on the position and circumstances of the limb itself
with its muscles. Here the Centre from which the re-
flection takes place is merely animal, not intellectual.
In this case some physiologists have doubted whether
the reflection of the sensation in the form of a muscular
236
PHILOSOPHY OF BIOLOGY.
contraction does really take place from the Center;
and have conceived that sensorial impressions might
affect motor nerves without any communication with
the nervous Center. But on this subject we may, I
conceive, with safety adopt the decision of Professor
Müller, deliberately given after a careful examination
of the subject: 'When impressions made by the action
of external stimuli on sensitive nerves give rise to
motions in other parts, these motions are never the
result of the direct reaction of the sensitive and motor
fibres of the nerves on each other; the irritation is
conveyed by the sensitive fibres to the brain and
spinal cord, and is by these communicated to the motor
fibres.'
22. Thus we have two extreme cases of the con-
nexion of sensation with muscular action; in one of
which the connexion clearly is, and in the other it as
clearly is not, determined by relations of Ideas, in its
transit through the nervous Center. There is another
highly curious case standing intermediate between these
two, and extremely difficult to refer to either. I speak
of the case of Instinct.
Instinct leads to actions which are such as if they
were determined by Ideas. The lamb follows its mother
by instinct; but the motions by which it does this, the
special muscular exertions, depend entirely upon the
geometrical and mechanical relations of external bodies,
as the form of the ground, and the force of the wind.
The contractions of the muscles which are requisite in
order that the creature may obey its instinct, vary with
every variation of these external conditions ;—are not
determined by any rule or necessity, but by properties
of Space and Force. Thus the action is not governed by
Sensations directly, but by sensations moulded by Ideas.
And the same is the case with other cases of instinct.
The dog hunts by instinct; but he hunts certain kinds
of animals merely, thus showing that his instinct acts
according to Resemblances and Differences; he crosses
the field repeatedly to find the track of his prey by
scent; thus recognizing the relations of Space with
reference to the track; he leaps, adjusting his Force to
IDEAS OF SEPARATE VITAL FORCES. 237
the distance and height of the leap with mechanical
precision; and thus he practically recognizes the Ideas
of Resemblance, Space, and Force.
But have animals such Ideas? In any proper sense
in which we can speak of possessing Ideas, it appears
plain that they have not. Animals cannot, at any
time, be said properly to possess ideas, for ideas imply
the possibility of speculative knowledge.
23. But even if we allow to animals only the prac-
tical possession of Ideas, we have still a great difficulty
remaining. In the case of man, his ideas are unfolded
gradually by his intercourse with the external world.
The child learns to distinguish forms and positions by
a repeated and incessant use of his hands and eyes; he
learns to walk, to run, to leap, by slow and laborious
degrees; he distinguishes one man from another, and
one animal from another, only after repeated mistakes.
Nor can we conceive this to be otherwise. How should
the child know at once what muscles he is to exert in
order to touch with his hand a certain visible object?
How should he know what muscles to exert that he
may stand and not fall, till he has tried often? How
should he learn to direct his attention to the differences
of different faces and persons, till he is roused by some
memory, or hope which implies memory? It seems to
us as if the sensations could not, without considerable
practice, be rightly referred to Ideas of Space, Force,
Resemblance, and the like.
Yet that which thus appears impossible, is in fact
done by animals. The lamb almost immediately after
its birth follows its mother, accommodating the actions
of its muscles to the form of the ground. The chick,
just escaped from the shell, picks up a minute insect,
directing its beak with the greatest accuracy. Even
the human infant seeks the breast and exerts its mus-
cles in sucking, almost as soon as it is born. Hence,
then, we see that Instinct produces at once actions
regulated by Ideas, or, at least, which take place as if
they were regulated by Ideas; although the Ideas can-
not have been developed by exercise, and only appear
to exist so far as such actions are concerned.
238
PHILOSOPHY OF BIOLOGY.
24. The term Instinct may properly be opposed to
Insight. The former implies an inward principle of
action, implanted within a creature and practically
impelling it, but not capable of being developed into
a subject of contemplation. While the instinctive
actions of animals are directed by such a principle,
the deliberate actions of man are governed by insight:
he can contemplate the ideal relations on which the
result of his action depends. He can in his mind map
the path he will follow, and estimate the force he will
exert, and class the objects he has to deal with, and
determine his actions by the relations which he thus
has present to his mind. He thus possesses Ideas not
only practically, but speculatively. And knowing that
the Ideas by which he commonly directs his actions,
Space, Cause, Resemblance, and the like, have been
developed to that degree of clearness in which he pos-
sesses them by the assiduous exercise of the senses and
the mind from the earliest stage of infancy, and that
these Ideas are capable of being still further unfolded
into long trains of speculative truth, he is unable to
conceive the manner in which animals possess such
Ideas as their instinctive actions disclose :-Ideas
which neither require to be unfolded nor admit of
unfolding; which are adequate for practical purposes
without any previous exercise, and inadequate for spe-
culative purposes with whatever labour cultivated.
I have ventured to make these few remarks on In-
stinct since it may, perhaps, justly be considered as the
last province of Biology, where we reach the boundary
line of Psychology. I have now, before quitting this
subject, only one other principle to speak of.
CHAPTER VI.
OF THE IDEA OF FINAL CAUSES.
J.
BY
Y an examination of those notions which enter
into all our reasonings and judgments on living
things, it appeared that we conceive animal life as a
vortex or cycle of moving matter in which the form of
the vortex determines the motions, and these motions
again support the form of the vortex: the stationary
parts circulate the fluids, and the fluids nourish the
permanent parts. Each portion ministers to the
others, each depends upon the other. The parts make
up the whole, but the existence of the whole is essen-
tial to the preservation of the parts. But parts exist-
ing under such conditions are organs, and the whole
is organized. This is the fundamental conception of
organization. ‘Organized beings,' says the physiologist',
are composed of a number of essential and mutually
dependent parts.' 'An organized product of nature,'
says the great metaphysician', 'is that in which all the
parts are mutually ends and means.'
2.
It will be observed that we do not content our-
selves with saying that in such a whole, all the parts
are mutually dependent. This might be true even of
a mechanical structure; it would be easy to imagine a
framework in which each part should be necessary to
the support of each of the others; for example, an arch
of several stones. But in such a structure, the parts
have no properties which they derive from the whole.
They are beams or stones when separate; they are no
more when joined. But the same is not the case in an
organized whole. The limb of an animal separated
1 Müller, Elem. p. 18,
2 Kant, Urtheilskraft, p. 296.
240
PHILOSOPHY OF BIOLOGY.
from the body, loses the properties of a limb, and soon
ceases to retain even its form.
3. Nor do we content ourselves with saying that
the parts are mutually causes and effects. This is the
case in machinery. In a clock, the pendulum by means
of the escapement causes the descent of the weight, the
weight by the same escapement keeps up the motion
of the pendulum. But things of this kind may happen
by accident. Stones slide from a rock down the side
of a hill and cause it to be smooth; the smoothness of
the slope causes stones still to slide. Yet no one would
call such a slide an organized system. The system is
organized, when the effects which take place among the
parts are essential to our conception of the whole; when
the whole would not be a whole, nor the parts, parts,
except these effects were produced; when the effects
not only happen in fact, but are included in the idea
of the object; when they are not only seen, but fore-
seen; not only expected, but intended: in short when,
instead of being causes and effects, they are ends and
means, as they are termed in the above definition.
4.
Thus we necessarily include, in our Idea of Organi-
zation, the notion of an End, a Purpose, a Design;
or, to use another phrase which has been peculiarly
appropriated in this case, a Final Cause. This idea of
a Final Cause is an essential condition in order to the
pursuing our researches respecting organized bodies.
This Idea of Final Cause is not deduced from
the phenomena by reasoning, but is assumed as the
only condition under which we can reason on such sub-
jects at all. We do not deduce the Idea of Space, or
Time, or efficient Cause from the phenomena about us,
but necessarily look at phenomena as subordinate to
these Ideas from the beginning of our reasoning. It
is true, our ideas of relations of Space, and Time, and
Force, may become much more clear by our familiariz-
ing ourselves with particular phenomena: but still,
the Fundamental Ideas are not generated, but un-
folded; not extracted from the external world, but
evolved from the world within. In like manner, in
the contemplation of organic structures, we consider
IDEA OF FINAL CAUSES.
241
each part as subservient to some use, and we cannot
study the structure as organic without such a conception.
This notion of adaptation,—this Idea of an End,—may
become much more clear and impressive by seeing it
exemplified in particular cases. But still, though sug-
gested and evoked by special cases, it is not furnished
by them.
If it be not supplied by the mind itself, it
can never be logically deduced from the phenomena.
It is not a portion of the facts which we study, but it
is a principle which connects, includes, and renders
them intelligible; as our other Fundamental Ideas do
the classes of facts to which they respectively apply.
5. This has already been confirmed by reference to
fact; in the History of Physiology, I have shown that
those who studied the structure of animals were irre-
sistibly led to the conviction that the parts of this
structure have each its end or purpose; that each
member and organ not merely produces a certain
effect or answers a certain use, but is so framed as
to impress us with the persuasion that it was con-
structed for that use:-that it was intended to pro-
duce the effect. It was there seen that this persua-
sion was repeatedly expressed in the most emphatic
manner by Galen;—that it directed the researches and
led to the discoveries of Harvey;-that it has always
been dwelt upon as a favourite contemplation, and fol-
lowed as a certain guide, by the best anatomists;—and
that it is inculcated by the physiologists of the pro-
foundest views and most extensive knowledge of our
own time. All these persons have deemed it a most
certain and important principle of physiology, that in
every organized structure, plant or animal, each intel-
ligible part has its allotted office:-each organ is de-
signed for its appropriate function:-that nature, in
these cases, produces nothing in vain: that, in short,
each portion of the whole arrangement has its final
cause; an End to which it is adapted, and in this End,
the reason that it is where and what it is.
6. This Notion of Design in organized bodies must,
I say, be supplied by the student of organization out of
his own mind: a truth which will become clearer if
VOL. II.
R
242
PHILOSOPHY OF BIOLOGY.
we attend to the most conspicuous and acknowledged
instances of design. The structure of the Eye, in which
the parts are curiously adjusted so as to produce a dis-
tinct image on the retina, as in an optical instrument;
-the Trochlear Muscle of the eye, in which the tendon
passes round a support and turns back, like a rope
round a pulley;-the prospective contrivances for the
preservation of animals, provided long before they are
wanted, as the Milk of the mother, the Teeth of the
child, the Eyes and Lungs of the fœtus:- these arrange-
ments, and innumerable others, call up in us a persua-
sion that Design has entered into the plan of animal
form and progress. And if we bring in our minds
this conception of Design, nothing can more fully
square with and fit it, than such instances as these.
But if we did not already possess the Idea of Design;
-if we had not had our notion of mechanical con-
trivance awakened by inspection of optical instruments,
or pulleys, or in some other way;-if we had never
been conscious ourselves of providing for the future;—
if this were the case, we could not recognize contriv-
ance and prospectiveness in such instances as we have
referred to. The facts are, indeed, admirably in ac-
cordance with these conceptions, when the two are
brought together: but the facts and the conceptions
come together from different quarters-from without
and from within.
7. We may further illustrate this point by referring
to the relations of travellers who tell us that when
consummate examples of human mechanical contriv-
ance have been set before savages, they have ap-
peared incapable of apprehending them as proofs of
design. This shows that in such cases the Idea of
Design had not been developed in the minds of the
people who were thus unintelligent: but it no more
proves that such an idea does not naturally and neces-
sarily arise, in the progress of men's minds, than the
confused manner in which the same savages apprehend
the relations of space, or number, or cause, proves that
these ideas do not naturally belong to their intellects.
All men have these ideas; and it is because they can-
IDEA OF FINAL CAUSES.
243
not help referring their sensations to such ideas, that
they apprehend the world as existing in time and
space, and as a series of causes and effects. It would
be very erroneous to say that the belief of such truths
is obtained by logical reasoning from facts. And in
like manner we cannot logically deduce design from
the contemplation of organic structures; although it is
impossible for us, when the facts are clearly before us,
not to find a reference to design operating in our minds.
8. Again; the evidence of the doctrine of Final
Causes as a fundamental principle of Biology may be
obscured and weakened in some minds by the constant
habit of viewing this doctrine with suspicion as unphi-
losophical and at variance with Morphology. By che-
rishing such views, it is probable that many persons,
physiologists and others, have gradually brought them-
selves to suppose that many or most of the arrange-
ments which are familiarly adduced as instances of de-
sign may be accounted for, or explained away;—that
there is a certain degree of prejudice and narrowness
of comprehension in that lively admiration of the
adaptation of means to ends which common minds
derive from the spectacle of organic arrangements.
And yet, even in persons accustomed to these views,
the strong and natural influence of the Idea of a Final
Cause, the spontaneous recognition of the relation of
Means to an End as the assumption which makes or-
ganic arrangements intelligible, breaks forth when we
bring before them a new case, with regard to which
their genuine convictions have not yet been modified
by their intellectual habits. I will offer, as an example
which may serve to illustrate this, the discoveries re-
cently made with regard to the process of Suckling in
the Kangaroo. In the case of this, as of other pouched
animals, the young animal is removed, while very
small and imperfectly formed, from the womb to the
pouch, in which the teats are, and is there placed
with its lips against one of the nipples. But the
young animal taken altogether is not so large as the
nipple, and is therefore incapable of sucking after the
manner of common mammals. Here is a difficulty:
R 2
244
PHILOSOPHY OF BIOLOGY.
how is it overcome?-By an appropriate contrivance :
the nipple, which in common mammals is not furnished
with any muscle, is in the kangaroo provided with a
powerful extrusory muscle by which the mother can
inject the milk into the mouth of her offspring. And
again; in order to give attachment to this muscle
there is a bone which is not found in animals of
other kinds. But this mode of solving the problem
of suckling so small a creature introduces another
difficulty. If the milk is injected into the mouth of
the young one, without any action of its own muscles,
what is to prevent the fluid entering the windpipe and
producing suffocation? How is this danger avoided ?—
By another appropriate contrivance: there is a funnel
in the back of the throat by which the air passage is
completely separated from the passage for nutriment,
and the injected milk passes in a divided stream on
each side of the larynx to the œsophagus.
And as if
to show that this apparatus is really formed with a
view to the wants of the young one, the structure
alters in the course of the animal's growth; and the
funnel, no longer needed, is modified and disappears.
With regard to this and similar examples, the re-
mark which I would urge is this:-that no one, how-
ever prejudiced or unphilosophical he may in general
deem the reference to Final Causes, can, at the first
impression, help regarding this curious system of ar-
rangement as the Means to an End. So contemplated,
it becomes significant, intelligible, admirable: without
such a principle, it is an unmeaning complexity, a col-
lection of contradictions, producing an almost impos-
sible result by a portentous conflict of chances. The
parts of this apparatus cannot have produced one ano-
ther: one part is in the mother; another part in the
young one without their harmony they could not be
effective; but nothing except design can operate to
make them harmonious. They are intended to work
together; and we cannot resist the conviction of this
intention when the facts first come before us. Perhaps
3. Mr. Owen, in Phil. Trans. 1834, P. 348.
IDEA OF FINAL CAUSES.
245
there may hereafter be physiologists who, tracing the
gradual development of the parts of which we have
spoken, and the analogies which connect them with
the structures of other animals, may think that this
development, these analogies, account for the confor-
mation we have described and may hence think
lightly of the explanation derived from the reference
to Final Causes. Yet surely it is clear, on a calm
consideration of the subject, that the latter explana-
tion is not disturbed by the former; and that the ob-
server's first impression, that this is an irrefragable
evidence of creative foresight,' can never be obli-
terated; however much it may be obscured in the
minds of those who confuse this view by mixing it
with others which are utterly heterogeneous to it, and
therefore cannot be contradictory.
5
9. I have elsewhere remarked how physiologists,
who thus look with suspicion and dislike upon the
introduction of Final Causes into physiology, have still
been unable to exclude from their speculations causes
of this kind. Thus Cabanis says, 'I regard with the
great Bacon, the philosophy of Final Causes as sterile;
but I have elsewhere acknowledged that it was very
difficult for the most cautious man never to have
recourse to them in his explanations.' Accordingly, he
says, 'The partisans of Final Causes nowhere find argu-
ments so strong in favour of their way of looking at
nature as in the laws which preside and the circum-
stances of all kinds which concur in the reproduction
of living races. In no case do the means employed
appear so clearly relative to the end.' And it would
be easy to find similar acknowledgments, express or
virtual, in other writers of the same kind. Thus
Bichat, after noting the difference between the organic
sensibility by which the organs are made to perform
their offices, and the animal sensibility of which the
4 Mr. Owen, in Phil. Trans. 1834, P. 349.
5 Bridgewater Treatise, p. 352.
6
• Rapports du Physique et du Moral, i. 299.
246
PHILOSOPHY OF BIOLOGY.
nervous center is the seat, says', 'No doubt it will be
asked, why'—that is, as we shall see, for what end—
'the organs of internal life have received from nature
an inferior degree of sensibility only, and why they do
not transmit to the brain the impressions which they
receive, while all the acts of the animal life imply this
transmission? The reason is simply this, that all the
phenomena which establish our connexions with sur-
rounding objects ought to be, and are in fact, under the
influence of the Will; while all those which serve for
the purpose of assimilation only, escape, and ought
indeed to escape, such influence.' The reason here
assigned is the Final Cause; which, as Bichat justly
says, we cannot help asking for.
10. Again; I may quote from the writer last men-
tioned another remark, which shows that in the organi-
cal sciences, and in them alone, the Idea of forces as
Means acting to an End, is inevitably assumed and
acknowledged as of supreme authority. In Biology
alone, observes Bichat, have we to contemplate the
state of Disease. 'Physiology is to the movements of
living bodies, what astronomy, dynamics, hydraulics,
&c., are to those of inert matter: but these latter
sciences have no branches which correspond to them
as Pathology corresponds to Physiology. For the same
reason all notion of a Medicament is repugnant to the
physical sciences. A Medicament has for its object
to bring the properties of the system back to their
Natural Type; but the physical properties never depart
from this Type, and have no need to be brought back to
it and thus there is nothing in the physical sciences
which holds the place of Therapeutick in Physiology.'
Or, as we might express it otherwise, of inert forces
we have no conception of what they ought to do,
except what they do. The forces of gravity, elasticity,
affinity, never act in a diseased manner; we never
conceive them as failing in their purpose; for we do
not conceive them as having any purpose which is
answered by one mode of their action rather than
7 Life and Death, (trans.) p. 32.
8 Anatomie Générale, i. liii.
IDEA OF FINAL CAUSES.
247
another. But with organical forces the case is differ-
ent; they are necessarily conceived as acting for the
preservation and development of the system in which
they reside. If they do not do this, they fail, they
are deranged, diseased. They have for their object
to conform the living being to a certain type; and if
they cause or allow it to deviate from this type, their
action is distorted, morbid, contrary to the ends of
nature. And thus this conception of organized beings
as susceptible of disease, implies the recognition of a
state of health, and of the organs and the vital forces
as means for preserving this normal condition.
state of health, and of perpetual development, is
necessarily contemplated as the Final Cause of the pro-
cesses and powers with which the different parts of
plants and animals are endowed.
The
II. This Idea of a Final Cause is applicable as a
fundamental and regulative idea to our speculations
concerning organized creatures only. That there is a
purpose in many other parts of the creation, we find
abundant reason to believe, from the arrangements
and laws which prevail around us.
But this per-
suasion is not to be allowed to regulate and direct our
reasonings with regard to inorganic matter, of which
conception the relation of means and end forms no
essential part. In mere Physics, Final Causes, as
Bacon has observed, are not to be admitted as a prin-
ciple of reasoning. But in the organical sciences, the
assumption of design and purpose in every part of
every whole, that is, the pervading idea of Final Cause,
is the basis of sound reasoning and the source of true
doctrine.
12.
The Idea of Final Cause, of end, purpose,
design, intention, is altogether different from the Idea
of Cause, as Efficient Cause, which we formerly had to
consider; and on this account the use of the word
Cause in this phrase has been objected to. If the idea
be clearly entertained and steadily applied, the word is
a question of subordinate importance. The term Final
Cause has been long familiarly used, and appears not
likely to lead to confusion.
248
PHILOSOPHY OF BIOLOGY.
13. The consideration of Final Causes, both in phy-
siology and in other subjects, has at all times attracted
much attention, in consequence of its bearing upon the
belief of an Intelligent Author of the Universe. I do
not intend, in this place, to pursue the subject far in
this view but there is one antithesis of opinion,
already noticed in the History of Physiology, on which
I will again make a few remarksº.
It has appeared to some persons that the mere
aspect of order and symmetry in the works of nature-
the contemplation of comprehensive and consistent
law—is sufficient to lead us to the conception of a
design and intelligence producing the order and carry-
ing into effect the law. Without here attempting to
decide whether this is true, we may discern, after what
has been said, that the conception of Design, arrived
at in this manner, is altogether different from that Idea
of Design which is suggested to us by organized bodies,
and which we describe as, the doctrine of Final Causes.
The regular form of a crystal, whatever beautiful sym-
metry it may exhibit, whatever general laws it may
exemplify, does not prove design in the same manner in
which design is proved by the provisions for the pre-
servation and growth of the seeds of plants, and of the
young of animals. The law of universal gravitation,
however wide and simple, does not impress us with the
belief of a purpose, as does that propensity by which
the two sexes of each animal are brought together. If
it could be shown that the symmetrical structure of a
flower results from laws of the same kind as those
which determine the regular forms of crystals, or the
motions of the planets, the discovery might be very
striking and important, but it would not at all come
under our idea of Final Cause.
14. Accordingly, there have been, in modern times,
two different schools of physiologists, the one proceed-
ing upon the idea of Final Causes, the other school
9 Hist, Ind. Sc. b. xvii, c. viii. On the Doctrine of Final Causes in Phy-
siology.
IDEA OF FINAL CAUSES.
249
seeking in the realm of organized bodies wide laws and
analogies from which that idea is excluded. All the
great biologists of preceding times, and some of the
greatest of modern times, have belonged to the former
school; and especially Cuvier, who may be considered
as the head of it. It was solely by the assiduous ap-
plication of this principle of Final Cause, as he himself
constantly declared, that he was enabled to make the
discoveries which have rendered his name so illustrious,
and which contain a far larger portion of important
anatomical and biological truth than it ever before fell
to the lot of one man to contribute to the science.
The opinions which have been put in opposition to
the principle of Final Causes have, for the most part,
been stated vaguely and ambiguously. Among the
most definite of such principles, is that which, in the
History of the subject, I have termed the Principle of
Metamorphosed and Developed Symmetry, upon which
has been founded the science. of Morphology.
The reality and importance of this principle are not
to be denied by us: we have shown how they are
proved by its application in various sciences, and espe-
cially in botany. But those advocates of this principle
who have placed it in antithesis to the doctrine of
Final Causes, have, by this means, done far more in-
justice to their own favourite doctrine than damage to
the one which they opposed. The adaptation of the
bones of the skeleton to the muscles, the provision of
fulcrums, projecting processes, channels, so that the
motions and forces shall be such as the needs of life
require, cannot possibly become less striking and con-
vincing, from any discovery of general analogies of one
animal frame with another, or of laws connecting the
development of different parts. Whenever such laws
are discovered, we can only consider them as the means
of producing that adaptation which we so much admire.
Our conviction that the Artist works intelligently, is
not destroyed, though it may be modified and trans-
ferred, when we obtain a sight of his tools. Our dis-
covery of laws cannot contradict our persuasion of
ends; our Morphology cannot prejudice our Teleology.
250
PHILOSOPHY OF BIOLOGY.
15. The irresistible and constant apprehension of a
purpose in the forms and functions of animals has in-
troduced into the writings of speculators on these sub-
jects various forms of expression, more or less precise,
more or less figurative; as, that 'animals are framed
with a view to the part which they have to play;'-
that ‘nature does nothing in vain;' that 'she employs
the best means for her ends;' and the like. However
metaphorical or inexact any of these phrases may be
in particular, yet taken altogether, they convey, clearly
and definitely enough to preclude any serious errour,
a principle of the most profound reality and of the
highest importance in the organical sciences. But
some adherents of the morphological school of which
I have spoken reject, and even ridicule, all such modes
of expression. 'I know nothing,' says M. Geoffroy
Saint Hilaire, 'of animals which have to play a part in
nature. I cannot make of nature an intelligent being
who does nothing in vain; who acts by the shortest
mode; who does all for the best.' The philosophers of this
school, therefore, do not, it would seem, feel any of the
admiration which is irresistibly excited in all the rest of
mankind at the contemplation of the various and won-
derful adaptations for the preservation, the enjoyment,
the continuation of the creatures which people the globe ;
—at the survey of the mechanical contrivances, the
chemical agencies, the prospective arrangements, the
compensations, the minute adaptations, the comprehen-
sive interdependencies, which zoology and physiology
have brought into view, more and more, the further their
researches have been carried. Yet the clear and deep-
seated conviction of the reality of these provisions,
which the study of anatomy produces in its most pro-
found and accurate cultivators, cannot be shaken by
any objections to the metaphors or terms in which this
conviction is clothed. In regard to the Idea of a Pur-
pose in organization, as in regard to any other idea, we
cannot fully express our meaning by phrases borrowed
from any extraneous source; but that impossibility
arises precisely from the circumstance of its being a
Fundamental Idea which is inevitably assumed in our
IDEA OF FINAL CAUSES.
251
representation of each special fact. The same objection
has been made to the idea of mechanical force, on ac-
count of its being often expressed in metaphorical lan-
guage; for writers have spoken of an energy, effort, or
solicitation to motion; and bodies have been said to be
animated by a force. Such language, it has been urged,
implies volition, and the act of animated beings. But
the idea of Force as distinct from mere motion,-as
the Cause of motion, or of tendency to motion,—is not
on that account less real. We endeavour in vain to
conduct our mechanical reasonings without the aid of
this idea, and must express it as we can.
Just as
little can we reason concerning organized beings with-
out assuming that each part has its function, each
function its purpose; and so far as our phrases im-
ply this, they will not mislead us, however inexact,
or however figurative they be.
16. The doctrine of a purpose in Organization has
been sometimes called the doctrine of the Conditions of
Existence; and has been stated as teaching that each
animal must be so framed as to contain in its structure
the Conditions which its existence requires. When
expressed in this manner, it has given rise to the ob-
jection, that it merely offers an identical proposition;
since no animal can exist without such conditions.
But in reality, such expressions as those just quoted
give an inadequate statement of the Principle of a
Final Cause. For we discover in innumerable cases,
arrangements in an animal, of which we see, indeed,
that they are subservient to its well being; but the
nature of which we never should have been able at all
to conjecture, from considering what was necessary to
its existence, and which strike us, no less by their un-
expectedness than by their adaptation: so far are they
from being presented by any perceptible necessity.
Who would venture to say that the trochlear muscle,
or the power of articulate speech, must occur in man,
because they are the necessary conditions of his exist-
ence? When, indeed, the general scheme and mode of
being of an animal are known, the expert and profound
anatomist can reason concerning the proportions and
252
PHILOSOPHY OF BIOLOGY.
form of its various parts and organs, and prove in some
measure what their relations must be. We can assert,
with Cuvier, that certain forms of the viscera require
certain forms of the teeth, certain forms of the limbs,
certain powers of the senses. But in all this, the func-
tions of self-nutrition and digestion are supposed al-
ready existing as ends: and it being taken for granted,
as the only conceivable basis of reasoning, that the
organs are means to these ends, we may discover what
modifications of these organs are necessarily related to
and connected with each other. Instead of terming
this rule of speculation merely 'the Principle of the
Conditions of Existence,' we might term it 'the Prin-
ciple of the conditions of organs as Means adapted to
animal existence as their End.' And how far this
principle is from being a mere barren truism, the
extraordinary discoveries made by the great assertor
of the principle, and universally assented to by natu-
ralists, abundantly prove. The vast extinct creation
which is recalled to life in Cuvier's great work, the
Ossemens Fossiles, cannot be the consequence of a mere
identical proposition.
17. It has been objected, also, that the doctrine of
Final Causes supposes us to be acquainted with the
intentions of the Creator; which, it is insinuated, is a
most presumptuous and irrational basis for our reason-
ings. But there can be nothing presumptuous or irra-
tional in reasoning on that basis, which if we reject,
we cannot reason at all. If men really can discern,
and cannot help discerning, a design in certain por-
tions of the works of creation, this perception is the
soundest and most satisfactory ground for the convic-
tions to which it leads. The Ideas which we necessa-
rily employ in the contemplation of the world around
us, afford us the only natural means of forming any
conception of the Creator and Governor of the Uni-
verse; and if we are by such means enabled to elevate
our thoughts, however inadequately, towards Him,
where is the presumption of doing so? or rather,
where is the wisdom of refusing to open our minds
to contemplations so animating and elevating,, and yet
IDEA OF FINAL CAUSES,
253
so entirely convincing? We possess the ideas of Time
and Space, under which all the objects of the universe
present themselves to us; and in virtue of these ideas
thus possessed, we believe the Creator to be eternal
and omnipotent. When we find that we, in like man-
ner, possess the idea of a Design in Creation, and that
with regard to ourselves, and creatures more or less
resembling ourselves, we cannot but contemplate their
constitution under this idea, we cannot abstain from
ascribing to the Creator the infinite profundity and
extent of design to which all these special instances
belong as parts of a whole.
The
18. I have here considered Design as manifest in
organization only: for in that field of speculation it is
forced upon us as contained in all the phenomena, and
as the only mode of our understanding them.
existence of Final Causes has often been pointed out
in other portions of the creation;—for instance, in the
apparent adaptations of the various parts of the earth
and of the solar system to each other and to organized
beings. In these provinces of speculation, however,
the principle of Final Causes is no longer the basis
and guide, but the sequel and result of our physical
reasonings. If in looking at the universe, we follow
the widest analogies of which we obtain a view, we
see, however dimly, reason to believe that all its laws
are adapted to each other, and intended to work toge-
ther for the benefit of its organic population, and for
the general welfare of its rational tenants. On this
subject, however, not immediately included in the prin-
ciple of Final Causes as here stated, I shall not dwell.
I will only make this remark; that the assertion ap-
pears to be quite unfounded, that as science advances
from point to point, Final Causes recede before it, and
disappear one after the other. The principle of design
changes its mode of application indeed, but it loses.
none of its force. We no longer consider particular
facts as produced by special interpositions, but we
consider design as exhibited in the establishment and
adjustment of the laws by which particular facts.
are produced. We do not look upon each particular
254
PHILOSOPHY OF BIOLOGY.
cloud as brought near us that it may drop fatness
on our fields; but the general adaptation of the laws
of heat, and air, and moisture, to the promotion of
vegetation, does not become doubtful. We do not
consider the sun as less intended to warm and vivify
the tribes of plants and animals, because we find that,
instead of revolving round the earth as an attendant,
the earth along with other planets revolves round him.
We are rather, by the discovery of the general laws
of nature, led into a scene of wider design, of deeper
contrivance, of more comprehensive adjustments. Final
causes, if they appear driven further from us by such
an extension of our views, embrace us only with a
vaster and more majestic circuit: instead of a few
threads connecting some detached objects, they be-
come a stupendous net-work, which is wound round
and round the universal frame of things.
19. I now quit the subject of Biology, and with it
the circle of sciences depending upon separate original
Ideas and permanent relations. If from the general
relations which permanently prevail and constantly
recur among the objects around us, we turn to the
inquiry of what has actually happened,-if from Sci-
ence we turn to History,-we find ourselves in a new
field. In this region of speculation we can rarely
obtain a complete and scientific view of the connex-
ion between objects and events. The past History
of Man, of the Arts, of Languages, of the Earth, of
the Solar System, offers a vast series of problems, of
which perhaps not one has been rigorously solved.
Still, man, as his speculative powers unfold themselves,
cannot but feel prompted and invited to employ his
thoughts even on these problems. He cannot but
wish and endeavour to understand the connexion be-
tween the successive links of such chains of events.
He attempts to form a Science which shall be appli-
cable to each of these Histories; and thus he begins to
construct the class of sciences to which I now, in the
last place, proceed.
BOOK X.
THE
PHILOSOPHY
OF
PALETIOLOGY.
Τὴν μὲν οὖν τοιαύτην Αἰτιολογίαν ηττον ἄν τις ἀποδέξαιτο·
μᾶλλον δ' ἀπὸ τῶν φανερωτέρων καὶ τῶν καθ᾽ ἡμέραν τρόπον
τινὰ ὁρωμένων ἀναπτέον τὸν λόγον. Καὶ γὰρ κατακλυσμοί, καὶ
σεισμοί, καὶ ἀναφυσήματα, καὶ ἀποιδήσεις τῆς ὑφάλου γῆς, μετεωρί
ζουσι καὶ τὴν θάλατταν· αἱ δὲ συνιζήσεις ταπεινοῦσιν αὐτήν.
STRABO, Geogr. I. p. 54›
For
Ir is therefore, not so much what these forms of the earth
actually are, as what they are continually becoming, that we
have to observe; nor is it possible thus to observe them without an
instinctive reference to the first state out of which they have
been brought.... Yet to such questions continually suggesting
themselves, it is never possible to give a complete answer.
a certain distance, the past work of existing forces can be traced
but then gradually the mist gathers, and the footsteps of more
gigantic agencies are traceable in the darkness; and still as we
endeavour to penetrate further and further into departed time, the
thunder of the Almighty power sounds louder and louder, and
the clouds gather broader and more fearfully, until at last the
Sinai of the world is seen altogether upon a smoke, and the
fence of its foot is reached, where none can break through.
RUSKIN, Modern Painters, Vol. IV. p. 143.
BOOK X.
THE PHILOSOPHY OF PALETIOLOGY.
I.
I
CHAPTER I.
OF PALETIOLOGICAL SCIENCES IN GENERAL.
HAVE already stated in the History of the
Sciences¹, that the class of Sciences which I
designate as Palatiological are those in which the ob-
ject is to ascend from the present state of things to a
more ancient condition, from which the present is de-
rived by intelligible causes. As conspicuous examples
of this class we may take Geology, Glossology or
Comparative Philology, and Comparative Archæology.
These provinces of knowledge might perhaps be in-
telligibly described as Histories; the History of the
Earth, the History of Languages, the History of
Arts. But these phrases would not fully describe
the sciences we have in view; for the object to which
we now suppose their investigations to be directed is,
not merely to ascertain what the series of events has
been, as in the common forms of History, but also how
it has been brought about. These sciences are to treat
of causes as well as of effects. Such researches might
be termed Philosophical History; or, in order to mark
more distinctly that the causes of events are the lead-
ing object of attention, Etiological History. But since
VOL. II.
1 B. xviii. Introd
S
258
PHILOSOPHY OF PALETIOLOGY.
it will be more convenient to describe this class of
sciences by a single appellation, I have taken the liberty
of proposing to call them² the Palatiological Sciences.
While Palaeontology describes the beings which have
lived in former ages without investigating their causes,
and Etiology treats of causes without distinguishing
historical from mechanical causation; Palatiology is a
combination of the two sciences; exploring, by means
of the second, the phenomena presented by the first.
The portions of knowledge which I include in this term
are palæontological ætiological sciences.
2. All these sciences are connected by this bond;-
that they all endeavour to ascend to a past state, by
considering what is the present state of things, and
what are the causes of change. Geology examines the
existing appearance of the materials which form the
earth, infers from them previous conditions, and specu-
lates concerning the forces by which one condition has
been made to succeed another. Another science, culti-
vated with great zeal and success in modern times,
compares the languages of different countries and na-
tions, and by an examination of their materials and
structure, endeavours to determine their descent from
one another: this science has been termed Compara-
tive Philology, or Ethnography; and by the French,
Linguistique, a word which we might imitate in order
to have a single name for the science, but the Greek
derivative Glossology appears to be more convenient in
its form. The progress of the Arts (Architecture and the
like);—how one stage of the culture produced another;
and how far we can trace their maturest and most com-
plete condition to their earliest form in various nations ;
-are problems of great interest belonging to another
subject, which we may for the present term Compara-
2 A philological writer, in a very
interesting work (Mr. Donaldson, in
his New Cratylus, p. 12), expresses
his dislike of this word, and suggests
that I must mean palæ-ætiological.
I think the word is more likely
to obtain currency in the more com-
pact and euphonious form in which
I have used it. It has been adopted
by Mr. Winning, in his Manual of
Comparative Philology, and more re-
cently, by other writers.
OF PALETIOLOGICAL SCIENCES IN GENERAL. 259
tive Archæology. I have already noticed, in the His-
tory³, how the researches into the origin of natural
objects, and those relating to works of art, pass by
slight gradations into each other; how the examina-
tion of the changes which have affected an ancient
temple or fortress, harbour or river, may concern alike
the geologist and the antiquary. Cuvier's assertion
that the geologist is an antiquary of a new order, is
perfectly correct, for both are palætiologists.
3. We are very far from having exhausted, by this
enumeration, the class of sciences which are thus con-
nected. We may easily point out many other subjects
of speculation of the same kind. As we may look back
towards the first condition of our planet, we may in
like manner turn our thoughts towards the first con-
dition of the solar system, and try whether we can dis-
cern any traces of an order of things antecedent to that
which is now established; and if we find, as some great
mathematicians have conceived, indications of an earlier
state in which the planets were not yet gathered into
their present forms, we have, in the pursuit of this
train of research, a palætiological portion of Astronomy.
Again, as we may inquire how languages, and how
man, have been diffused over the earth's surface from
place to place, we may make the like inquiry with
regard to the races of plants and animals, founding
our inferences upon the existing geographical distri-
bution of the animal and vegetable kingdoms: and
thus the Geography of Plants and of Animals also
becomes a portion of Palætiology. Again, as we can
in some measure trace the progress of Arts from nation
to nation and from age to age, we can also pursue a
similar investigation with respect to the progress of
Mythology, of Poetry, of Government, of Law. Thus
the philosophical history of the human race, viewed
with reference to these subjects, if it can give rise to
knowledge so exact as to be properly called Science,
will supply Sciences belonging to the class I am now to
consider.
3 B. xviii. Introd
S 2
260
PHILOSOPHY OF PALETIOLOGY.
4. It is not an arbitrary and useless proceeding to
construct such a Class of Sciences. For wide and vari-
ous as their subjects are, it will be found that they
have all certain principles, maxims, and rules of proce-
dure in common; and thus may reflect light upon each
other by being treated of together. Indeed it will,
I trust, appear, that we may by such a juxtaposition
of different speculations, obtain most salutary lessons.
And questions, which, when viewed as they first pre-
sent themselves under the aspect of a special science,
disturb and alarm men's minds, may perhaps be con-
templated more calmly, as well as more clearly, when
they are considered as general problems of palatio-
logy.
5. It will at once occur to the reader that, if we
include in the circuit of our classification such subjects
as have been mentioned,-politics and law, mythology
and poetry, we are travelling very far beyond the
material sciences within whose limits we at the outset
proposed to confine our discussion of principles. But
we shall remain faithful to our original plan; and for
that purpose shall confine ourselves, in this work, to
those palætiological sciences which deal with material ·
things. It is true, that the general principles and
maxims which regulate these sciences apply also to in-
vestigations of a parallel kind respecting the products
which result from man's imaginative and social endow-
ments. But although there may be a similarity in the
general form of such portions of knowledge, their ma-
terials are so different from those with which we have
been hitherto dealing, that we cannot hope to take
them into our present account with any profit. Lan-
guage, Government, Law, Poetry, Art, embrace a num-
ber of peculiar Fundamental Ideas, hitherto not touched
upon in the disquisitions in which we have been en-
gaged; and most of them involved in far greater per-
plexity and ambiguity, the subject of controversies far
more vehement, than the Ideas we have hitherto been
examining. We must therefore avoid resting any part
of our philosophy upon sciences, or supposed sciences,
which treat of such subjects. To attend to this caution,
OF PALETIOLOGICAL SCIENCES IN GENERAL. 261
is the only way in which we can secure the advantage
we proposed to ourselves at the outset, of taking, as
the basis of our speculations, none but systems of un-
disputed truths, clearly understood and expressed.
We have already said that we must, knowingly and
voluntarily, resign that livelier and warmer interest
which doctrines on subjects of Polity or Art possess,
and content ourselves with the cold truths of the
material sciences, in order that we may avoid having
the very foundations of our philosophy involved in con-
troversy, doubt, and obscurity.
6. We may remark, however, that the necessity of
rejecting from our survey a large portion of the re-
searches which the general notion of Palætiology in-
cludes, suggests one consideration which adds to the
interest of our task. We began our inquiry with the
trust that any sound views which we should be able
to obtain respecting the nature of Truth in the phy-
sical sciences, and the mode of discovering it, must
also tend to throw light upon the nature and pro-
spects of knowledge of all other kinds;-must be
useful to us in moral, political, and philological re-
searches. We stated this as a confident anticipation;
and the evidence of the justice of our belief already
begins to appear. We have seen, in the last Book, that
biology leads us to psychology, if we choose to follow
the path; and thus the passage from the material to
the immaterial has already unfolded itself at one point;
and we now perceive that there are several large pro-
vinces of speculation which concern subjects belonging
to man's immaterial nature, and which are governed
by the same laws as sciences altogether physical. It
is not our business here to dwell on the prospects
which our philosophy thus opens to our contempla-
tion; but we may allow ourselves, in this last stage
of our pilgrimage among the foundations of the phy-
sical sciences, to be cheered and animated by the ray
4 See Introd. p. 9.
262
PHILOSOPHY OF PALETIOLOGY.
that thus beams upon us, however dimly, from a
higher and brighter region.
But in our reasonings and examples we shall mainly
confine ourselves to the physical sciences; and for the
most part to Geology, which in the History I have put
forwards as the best representative of the Palætiolo-
gical Sciences.
CHAPTER II.
OF THE THREE MEMBERS OF A PALÆTIOLOGICAL
SCIENCE.
1. Divisions of such Sciences.-IN each of the Sci-
ences of this class we consider some particular order
of phenomena now existing:-from our knowledge of
the causes of change among such phenomena, we endea-
vour to infer the causes which have made this order of
things what it is:—we ascend in this manner to some
previous stage of such phenomena;-and from that, by
a similar course of inference, to a still earlier stage,
and to its causes. Hence it will be seen that each
such science will consist of two parts,—the knowledge
of the Phenomena, and the knowledge of their Causes.
And such a division is, in fact, generally recognized
in such sciences: thus we have History, and the Phi-
losophy of History; we have Comparison of Lan-
guages, and the Theories of the Origin and Progress
of Language; we have Descriptive Geology, and
Theoretical or Physical Geology. In all these cases,
the relation between the two parts in these several
provinces of knowledge is nearly the same; and it may,
on some occasions at least, be useful to express the
distinction in a uniform or general manner. The in-
vestigation of Causes has been termed Etiology by
philosophical writers, and this term we may use, in
contradistinction to the mere Phenomenology of each
such department of knowledge. And thus we should
have Phenomenal Geology and Etiological Geology, for
the two divisions of the science which we have above
termed Descriptive and Theoretical Geology.
2. The Study of Causes.-But our knowledge re-
specting the causes which actually have produced any
264
PHILOSOPHY OF PALÆTIOLOGY.
order of phenomena must be arrived at by ascertain-
ing what the causes of change in such matters can
do. In order to learn, for example, what share earth-
quakes, and volcanoes, and the beating of the ocean
against its shores, ought to have in our Theory of
Geology, we must make out what effects these agents
of change are able to produce. And this must be
done, not hastily, or unsystematically, but in a care-
ful and connected manner; in short, this study of
the causes of change in each order of phenomena must
become a distinct body of Science, which must include
a large amount of knowledge, both comprehensive and
precise, before it can be applied to the construction of
a theory. We must have an Etiology corresponding
to each order of phenomena.
3. Etiology. In the History of Geology, I have
spoken of the necessity for such an Etiology with
regard to geological phenomena: this necessity I have
compared with that which, at the time of Kepler, re-
quired the formation of a separate science of Dynamics
(the doctrine of the Causes of Motion), before Physical
Astronomy could grow out of Phenomenal Astronomy.
In pursuance of this analogy, I have there given the
name of Geological Dynamics to the science which
treats of the causes of geological change in general.
But, as I have there intimated, in a large portion of
the subject the changes are so utterly different in their
nature from any modification of motion, that the term
Dynamics, so applied, sounds harsh and strange. For
in this science we have to treat, not only of the subter-
raneous forces by which parts of the earth's crust are
shaken, elevated, or ruptured, but also of the causes
which may change the climate of a portion of the
earth's surface, making a country hotter or colder than
in former ages; again, we have to treat of the causes
which modify the forms and habits of animals and
vegetables, and of the extent to which the effects of
such causes can proceed; whether, for instance, they
can extinguish old species and produce new. These
and other similar investigations would not be naturally
included in the notion of Dynamics; and therefore it
MEMBERS OF A PALÆTIOLOGICAL SCIENCE. 265
might perhaps be better to use the term Etiology
when we wish to group together all those researches
which have it for their object to determine the laws
of such changes. In the same manner the Comparison
and History of Languages, if it is to lead to any
stable and exact knowledge, must have appended to
it an Ætiology, which aims at determining the nature
and the amount of the causes which really do produce
changes in language; as colonization, conquest, the
mixture of races, civilization, literature, and the like.
And the same rule applies to all sciences of this class.
We shall now make a few remarks on the charac-
teristics of such branches of science as those to which
we are led by the above considerations.
4. Phenomenology requires Classification. Phenome-
nal Geology.The Phenomenal portions of each science
imply Classification, for no description of a large and
varied mass of phenomena can be useful or intelligible
without classification. A representation of pheno-
mena, in order to answer the purposes of science, must
be systematic. Accordingly, in giving the History of
Descriptive or Phenomenal Geology, I have called it
Systematic Geology, just as Classificatory Botany is
termed Systematic Botany. Moreover, as we have
already seen, Classification can never be an arbitrary
process, but always implies some natural connexion
among the objects of the same Class; for if this con-
nexion did not exist, the Classes could not be made the
subjects of any true assertion. Yet though the classes
of phenomena which our system acknowledges must be
such as already exist in nature, the discovery of these
classes is, for the most part, very far from obvious or
easy. To detect the true principles of Natural Classes,
and to select marks by which these may be recognized,
are steps which require genius and good fortune, and
which fall to the lot only of the most eminent persons
in each science. In the History, I have pointed out
Werner, William Smith, and Cuvier, as the three
great authors of Systematic Geology of Europe. The
mode of classifying the materials of the earth's sur-
face which was found, by these philosophers, fitted to
266
PHILOSOPHY OF PALETIOLOGY.
enunciate such general facts as came under their no-
tice, was to consider the rocks and other materials as
divided into successive layers or strata, superimposed
one on another, and variously inclined and broken.
The German geologist distinguished his strata for the
most part by their mineralogical character; the other
two, by the remains of animals and plants which the
rocks contained. After a beginning had thus been
made in giving a genuine scientific form to phenomenal
geology, other steps followed in rapid succession, as has
already been related in the History'. The Classifica-
tion of the Strata was fixed by a suitable Nomencla-
ture. Attempts were made to apply to other countries
the order of strata which had been found to prevail in
that first studied: and in this manner it was ascer-
tained what rocks in distant regions are the synonyms,
or Equivalents², of each other. The knowledge thus
collected and systematized was exhibited in the form
of Geological Maps.
Moreover, among the phenomena of geology we have
Laws of Nature as well as Classes. The general form
of mountain-chains; the relations of the direction and
inclination of different chains to each other; the gene-
ral features of mineral veins, faults, and fissures; the
prevalent characters of slaty cleavage; were the sub-
jects of laws established, or supposed to be established,
by extensive observation of facts. In like manner the
organic fossils discovered in the strata were found to
follow certain laws with reference to the climate which
they appeared to have lived in; and the evidence which
they gave of a regular zoological development. And
thus, by the assiduous labours of many accomplished
and active philosophers, Descriptive or Phenomenal
Geology was carried towards a state of complete-
ness.
5. Phenomenal Uranography.-In like manner in
other palætiological researches, as soon as they ap-
proach to an exact and scientific form, we find the
necessity of constructing in the first place a science of
1 Hist. Ind. Sci. b. xviii. c. iii.
2 Ib. sect. 4.
MEMBERS OF A PALETIOLOGICAL SCIENCE. 267
classification and exact description, by means of which
the phenomena may be correctly represented and com-
pared; and of obtaining by this step a solid basis for
an inquiry into the causes which have produced them.
Thus the Palætiology of the Solar System has, in recent
times, drawn the attention of speculators; and a hypo-
thesis has been started, that our sun and his attendant
planets have been produced by the condensation of a
mass of diffused matter, such as that which constitutes
the nebulous patches which we observe in the starry
heavens. But the sagest and most enlightened astro-
nomers have not failed to acknowledge, that to verify
or to disprove this conjecture, must be the work of
many ages of observation and thought. They have
perceived also that the first step of the labour requi-
site for the advancement of this portion of science
must be to obtain and to record the most exact know-
ledge at present within our reach, respecting the phe-
nomena of these nebulæ, with which we thus compare
our own system; and, as a necessary element of such
knowledge, they have seen the importance of a classi-
fication of these objects, and of others, such as Double
Stars, of the same kind. Sir William Herschel, who
first perceived the bearing of the phenomena of nebula
upon the history of the solar system, made the obser-
vation of such objects his business, with truly admi-
rable zeal and skill; and in the account of the results
of his labours, gave a classification of Nebulæ; sepa-
rating them into, first, Clusters of Stars; second,
Resolvable Nebulae; third, Proper Nebulae; fourth,
Planetary Nebulae; fifth, Stellar Nebula; sixth, Nebu-
lous Stars³. And since, in order to obtain from these
remote appearances, any probable knowledge respect-
ing our own system, we must discover whether they
undergo any changes in the course of ages, he devoted
himself to the task of forming a record of their num-
ber and appearance in his own time, that thus the
astronomers of succeeding generations might have a
3 Phil. Trans. 1786 and 1789, and Sir J. Herschel's Astronomy, Art. 616.
268
PHILOSOPHY OF PALETIOLOGY.
definite and exact standard with which to compare
their observations. Still, this task would have been
executed only for that part of the heavens which is
visible in this country, if this Hipparchus of the
Nebula and Double Stars had not left behind him
a son who inherited all his father's zeal and more
than his father's knowledge. Sir John Herschel in
1833 went to the Cape of Good Hope to complete
what Sir William Herschel left wanting; and in the
course of five years observed with care all the nebulæ
and double stars of the Southern hemisphere. This
great Herschelian Survey of the Heavens, the comple-
tion of which is the noblest monument ever erected by
a son to a father, must necessarily be, to all ages, the
basis of all speculations concerning the history and
origin of the solar system; and has completed, so far
as at present it can be completed, the phenomenal por-
tion of Astronomical Palætiology.
6. Phenomenal Geography of Plants and Animals.
Again, there is another Palætiological Science,
closely connected with the speculations forced upon
the geologist by the organic fossils which he discovers
imbedded in the strata of the earth;-namely, the
Science which has for its object the Causes of the
Diffusion and Distribution of the various kinds of
Plants and Animals. And the science also has for
its first portion and indispensable foundation a de-
scription and classification of the existing phenomena.
Such portions of science have recently been cultivated
with great zeal and success, under the titles of the
Geography of Plants, and the Geography of Animals.
And the results of the inquiries thus undertaken have
assumed a definite and scientific form by leading to a
division of the earth's surface into a certain number of
botanical and zoological Provinces, each province occu-
pied by its own peculiar vegetable and animal population.
We find, too, in the course of these investigations,
various general laws of the phenomena offered to our
notice; such, for instance, as this:-that the difference
of the animals originally occupying each province,
which is clear and entire for the higher orders of
MEMBERS OF A PALETIOLOGICAL SCIENCE. 269
4
animals and plants, becomes more doubtful and in-
distinct when we descend to the lower kinds of or-
ganizations; as Infusoria and Zoophytes in the animal
kingdom, Grasses and Mosses among vegetables. Again,
other laws discovered by those who have studied the
geography of plants are these:-that countries sepa-
rated from each other by wide tracts of sea, as the
opposite shores of the Mediterranean, the islands of
the Indian and Pacific Oceans, have usually much that
is common in their vegetation:—and again, that in
parallel climates, analogous tribes replace each other.
It would be easy to adduce other laws, but those
already stated may serve to show the great extent of
the portions of knowledge which have just been men-
tioned, even considered as merely Sciences of Pheno-
mena.
7. Phenomenal Glossology.—It is not my purpose
in the present work to borrow my leading illustrations
from any portions of knowledge but those which are
concerned with the study of material nature; and I
shall, therefore, not dwell upon a branch of research, ·
singularly interesting, and closely connected with the
one just mentioned, but dealing with relations of
thought rather than of things;-I mean the Palætio-
logy of Language; the theory, so far as the facts
enable us to form a theory, of the causes which have
led to the resemblances and differences of human speech
in various regions and various ages. This, indeed,
would be only a portion of the study of the history
and origin of the diffusion of animals, if we were to
include man among the animals whose dispersion we
thus investigate; for language is one of the most clear
and imperishable records of the early events in the
career of the human race. But the peculiar nature of
the faculty of speech, and the ideas which the use of it
involves, make it proper to treat Glossology as a dis-
tinct science. And of this science, the first part must
necessarily be, as in the other sciences of this order, a
4 Prichard, Researches into the Physical History of Mankind, i. 55, 28.
270
PHILOSOPHY OF PALETIOLOGY.
classification and comparison of languages governed in
many respects by the same rules, and presenting the
same dfficulties, as other sciences of classification.
Such, accordingly, has been the procedure of the most
philosophical glossologists. They have been led to
throw the languages of the earth into certain large
classes or Families, according to various kinds of re-
semblance; as the Semitic Family, to which belong
Hebrew, Arabic, Chaldean, Syrian, Phoenician, Ethio-
pian, and the like; the Indo-European, which includes
Sanskrit, Persian, Greek, Latin, and German; the
Monosyllabic languages, Chinese, Tibetan, Birman,
Siamese; the Polysynthetic languages, a class including
most of the North-American Indian dialects; and
others. And this work of classification has been the
result of the labour and study of many very profound
linguists, and has advanced gradually from step to
step. Thus the Indo-European Family was first formed
on an observation of the coincidences between Sanskrit,
Greek, and Latin; but it was soon found to include
the Teutonic languages, and more recently Dr. Pri-
chard has shown beyond doubt that the Celtic must
be included in the same Family. Other general resem-
blances and differences of languages have been marked
by appropriate terms: thus August von Schlegel has
denominated them synthetical and analytical, accord-
ing as they form their conjugations and declensions by
auxiliary verbs and prepositions, or by changes in the
word itself: and the polysynthetic languages are so
named by M. Duponceau, in consequence of their still
more complex mode of inflexion. Nor are there want-
ing, in this science also, general laws of phenomena ;
such, for instance, is the curious rule of the inter-
change of consonants in the cognate words of Greek,
Gothic, and German, which has been discovered by
James Grimm. All these remarkable portions of know-
ledge, and the great works which have appeared on
Glossology, such, for example, as the Mithridates of
Adelung and Vater, contain, for their largest, and
5
5 Dr Prichard, On the Eastern Origin of the Celtic Nations. 1831.
•
MEMBERS OF A PALETIOLOGICAL SCIENCE. 271
hitherto probably their most valuable part, the pheno-
menal portion of the science, the comparison of lan-
guages as they now are. And beyond all doubt, until
we have brought this Comparative Philology to a con-
siderable degree of completeness, all our speculations
respecting the causes which have operated to produce
the languages of the earth must be idle and unsubstan-
tial dreams.
Thus in all Palætiological Sciences, in all attempts to
trace back the history and discover the origin of the
present state of things, the portion of the science which
must first be formed is that which classifies the pheno-
mena, and discovers general laws prevailing among
them. When this work is performed, and not till
then, we may begin to speculate successfully concern-
ing causes, and to make some progress in our attempts
to go back to an origin. We must have a Phenomenal
science preparatory to each Etiological one.
8. The Study of Phenomena leads to Theory.As
we have just said, we cannot, in any subject, speculate
successfully concerning the causes of the present state
of things, till we have obtained a tolerably complete
and systematic view of the phenomena. Yet in reality
men have not in any instance waited for this complete-
ness and system in their knowledge of facts before
they have begun to form theories. Nor was it natural,
considering the speculative propensities of the human
mind, and how incessantly it is endeavouring to apply
the Idea of Cause, that it should thus restrain itself.
I have already noticed this in the History of Geology.
'While we have been giving an account,' it is there
said, 'of the objects with which Descriptive Geology is
occupied, it must have been felt how difficult it is, in
contemplating such facts, to confine ourselves to de-
scription and classification. Conjectures and reason-
ings respecting the causes of the phenomena force
themselves upon us at every step; and even influ-
ence our classification and nomenclature. Our De-
scriptive Geology impels us to construct a Physical
Geology.' And the same is the case with regard to
the other subjects which I have mentioned. The mere
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PHILOSOPHY OF PALÆTIOLOGY.
consideration of the different degrees of condensation of
different Nebulæ led Herschel and Laplace to contem-
plate the hypothesis that our solar system is a con-
densed Nebula. Immediately upon the division of the
earth's surface into botanical and zoological provinces,
and even at an earlier period, the opposite hypotheses
of the Origin of all the animals of each kind from a
single pair, and of their original diffusion all over the
earth, were under discussion. And the consideration
of the families of languages irresistibly led to specula-
tions concerning the Families of the earliest human
inhabitants of the earth. In all cases the contempla-
tion of a very few phenomena, the discovery of a very
few steps in the history, made men wish for and at-
tempt to form a theory of the history from the very
beginning of things.
9. No sound Theory without Etiology. But though
man is thus impelled by the natural propensities of his
intellect to trace each order of things to its causes, he
does not at first discern the only sure way of obtaining
such knowledge: he does not suspect how much labour
and how much method are requisite for success in this
undertaking: he is not aware that for each order of
phenomena he must construct, by the accumulated re-
sults of multiplied observation and distinct thought, a
separate Etiology. Thus, as I have elsewhere re-
marked, when men had for the first time become
acquainted with some of the leading phenomena of
Geology, and had proceeded to speculate concerning
the past changes and revolutions by which such results
had been produced, they forthwith supposed themselves
able to judge what would be the effects of any of the
obvious agents of change, as Water or Volcanic Fire. It
did not at first occur to them to suspect that their
common and extemporaneous judgment on such points
was by no means sufficient for sound knowledge. They
did not foresee that, before they could determine what
share these or any other causes had had in producing
the present condition of the earth, they must create
6 Hist. Ind. Sc. b. xviii. c. v. sect. 1.
MEMBERS OF A PALETIOLOGICAL SCIENCE. 273
a special science whose object should be to estimate
the general laws and effects of such assumed causes;
—that before they could obtain any sound Geolo-
gical Theory, they must carefully cultivate Geological
Ætiology.
The same disposition to proceed immediately from
the facts to the theory, without constructing, as an in-
termediate step, a Science of Causes, might be pointed
out in the other sciences of this order. But in all of
them this errour has been corrected by the failures to
which it led. It soon appeared, for instance, that a
more careful inquiry into the effects which climate,
food, habit and circumstances can produce in animals,
was requisite in order to determine how the diversities
of animals in different countries have originated. The
Ætiology of Animal Life (if we may be allowed to
give this name to that study of such causes of change
which is at present so zealously cultivated, and which
yet has no distinctive designation, except so far as it
coincides with the Organic Geological Dynamics of our
History) is now perceived to be a necessary portion of
all attempts to construct a history of the earth and its
inhabitants.
10. Cause, in Palatiology.-We are thus led to
contemplate a class of Sciences which are commenced
with the study of Causes. We have already consider-
ed sciences which depended mainly upon the Idea of
Cause, namely, the Mechanical Sciences. But it is
obvious that the Idea of Cause in the researches now
under our consideration must be employed in a very
different way from that in which we applied it for-
merly. Force is the Cause of motion, because force
at all times and under all circumstances, if not counter-
acted, produces motion; but the Cause of the present
condition and elevation of the Alps, whatever it was,
was manifested in a series of events of which each hap-
pened but once, and occupied its proper place in the
series of time. The former is mechanical, the latter
historical, cause. In our present investigations, we
consider the events which we contemplate, of whatever
order they be, as forming a chain which is extended
VOL. II.
T
274
PHILOSOPHY OF PALETIOLOGY.
from the beginning of things down to the present time;
and the causes of which we now speak are those which
connect the successive links of this chain. Every oc-
currence which has taken place in the history of the
solar system, or the earth, or its vegetable and animal
creation, or man, has been at the same time effect and
cause; the effect of what preceded, the cause of what
succeeded. By being effect and cause, it has occupied
some certain portion of time; and the times which
have thus been occupied by effects and causes, sum-
med up and taken altogether, make up the total of
Past Time. The Past has been a series of events con-
nected by this historical causation, and the Present is
the last term of this series. The problem in the Palæ-
tiological Sciences, with which we are here concerned,
is, to determine the manner in which each term is de-
rived from the preceding, and thus, if possible, to cal-
culate backwards to the origin of the series.
II. Various kinds of Cause. Those modes by
which one term in the natural series of events is
derived from another, the forms of historical causa-
tion, the kinds of connexion between the links of
the infinite chain of time,—are very various; nor need
we attempt to enumerate them. But these kinds of
causation being distinguished from each other, and
separately studied, each becomes the subject of a
separate Ætiology. Thus the causes of change in the
earth's surface, residing in the elements, fire and water,
form the main subject of Geological Etiology. The
Etiology of the vegetable and animal kingdoms inves-
tigates the causes by which the forms and distribution
of species of plants and animals are affected. The
study of causes in Glossology leads to an Etiology of
Language, which shall distinguish, analyse, and esti-
mate the causes by which certain changes are produced
in the languages of nations; in like manner we may
expect to have an Etiology of Art, which shall
scrutinise the influences by which the various forms of
art have each given birth to its successor: by which,
for example, there have been brought into being those
various forms of architecture which we term Egyptian,
MEMBERS OF A PALETIOLOGICAL SCIENCE. 275
Doric, Ionic, Roman, Byzantine, Romanesque, Gothic,
Italian, Elizabethan. It is easily seen by this slight
survey how manifold and diverse are the kinds of
cause which the Palætiological Sciences bring under
our consideration. But in each of those sciences we
shall obtain solid and complete systems of knowledge,
only so far as we study, with steady thought and
careful observation, that peculiar kind of cause which
is appropriate to the phenomena under our considera-
tion.
12. Hypothetical Order of Palatiological Causes.-
The various kinds of historical cause are not only con-
nected with each other by their common bearing upon
the historical sciences, but they form a kind of pro-
gression which we may represent to ourselves as having
acted in succession in the hypothetical history of the
earth and its inhabitants. Thus assuming, merely as a
momentary hypothesis, the origin of the Solar System
by the condensation of a Nebula, we have to contem-
plate, first, the causes by which the luminous in-
candescent diffused mass of which a nebula is supposed
to be constituted, is gradually condensed, cooled,
collected into definite masses, solidified, and each
portion made to revolve about its axis, and the
whole to travel about another body. We have no
difficulty in ascribing the globular form of each mass
to the mutual attraction of its particles: but when
this form was once assumed, and covered with a solid
crust, are there, we may ask, in the constitution of
such a body, any causes at work by which the crust
might be again broken up and portions of it displaced,
and covered with other matter? Again, if we can thus
explain the origin of the Earth, can we with like suc-
cess account for the presence of the Atmosphere and
the Waters of earth and ocean? Supposing this done,
we have then to consider by what causes such a body
could become stocked with vegetable and animal Life;
for there have not been wanting persons, extravagant
speculators, no doubt, who have conceived that even this
event in the history of the world might be the work
of natural causes. Supposing an origin given to life
•
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276
PHILOSOPHY OF PALETIOLOGY.
upon our earth, we have then, brought before us by
geological observations, a series of different forms of
vegetable and animal existence; occurring in different
strata, and, as the phenomena appear irresistibly to
prove, existing at successive periods: and we are com-
pelled to inquire what can have been the causes by
which the forms of each period have passed into those
of the next. We find, too, that strata, which must
have been at first horizontal and continuous, have
undergone enormous dislocations and ruptures, and we
have to consider the possible effect of aqueous and
volcanic causes to produce such changes in the earth's
crust. We are thus led to the causes which have
produced the present state of things on the earth; and
these are causes to which we may hypothetically
ascribe, not only the form and position of the inert
materials of the earth, but also the nature and distri-
bution of its animal and vegetable population. Man
too, no less than other animals, is affected by the
operation of such causes as we have referred to, and
must, therefore, be included in such speculations. But
man's history only begins, where that of other animals
ends, with his mere existence. They are stationary,
he is progressive. Other species of animals, once
brought into being, continue the same through all
ages; man is changing, from age to age, his language,
his thoughts, his works. Yet even these changes are
bound together by laws of causation; and these causes
too may become objects of scientific study. And such
causes, though not to be dwelt upon now, since we
permit ourselves to found our philosophy upon the
material sciences only, must still, when treated scien-
tifically, fall within the principles of our philosophy,
and must be governed by the same general rules to
which all science is subject. And thus we are led by
a close and natural connexion, through a series of
causes, extending from those which regulate the imper-
ceptible changes of the remotest nebulæ in the heavens,
to those which determine the diversities of language,
the mutations of art, and even the progress of civiliza-
tion, polity, and literature.
MEMBERS OF A PALÆTIOLOGICAL SCIENCE. 277
While I have been speaking of this supposed series
of events, including in its course the formation of the
earth, the introduction of animal and vegetable life,
and the revolutions by which one collection of species
has succeeded another, it must not be forgotten, that
though I have thus hypothetically spoken of these
events as occurring by force of natural causes, this has
been done only that the true efficacy of such causes
might be brought under our consideration and made
the subject of scientific examination. It may be found,
that such occurrences as these are quite inexplicable
by the aid of any natural causes with which we are
acquainted; and thus, the result of our investigations,
conducted with strict regard to scientific principles,
may be, that we must either contemplate supernatural
influences as part of the past series of events, or declare
ourselves altogether unable to form this series into a
connected chain.
13. Mode of Cultivating Etiology:—In Geology.—
In what manner, it may be asked, is Etiology, with
regard to each subject such as we have enumerated, to
be cultivated? In order to answer this question, we
must, according to our method of proceeding, take the
most successful and complete examples which we pos-
But in truth, we can
sess of such portions of science.
as yet refer to few examples of this kind. In Geo-
logy, it is only very recently, and principally through
the example and influence of Sir Charles Lyell, that
the Etiology has been detached from the descriptive
portion of the science; and cultivated with direct
attention: in other sciences the separation has hardly
yet been made. But if we examine what has already
been done in Geological Ætiology, or as in the History
it is termed, Geological Dynamics, we shall find a
number of different kinds of investigation which,
by the aid of our general principles respecting the for-
mation of sciences, may suffice to supply very useful
suggestions for Etiology in general.
In Geological Etiology, causes have been studied, in
many instances, by attending to their action in the phe-
nomena of the present state of things, and by inferring
278
PHILOSOPHY OF PALETIOLOGY.
from this the nature and extent of the action which
they may have exercised in former times. This has
been done, for example, by Von Hoff, Sir Charles Lyell,
and others, with regard to the operations of rivers, seas,
springs, glaciers, and other aqueous causes of change.
Again, the same course has been followed by the same
philosophers with respect to volcanoes, earthquakes, and
other violent agents. Sir Charles Lyell has attempted
to show, too, that there take place, in our own time,
not only violent agitations, but slow motions of parts
of the earth's crust, of the same kind and order with
those which have assisted in producing all anterior
changes.
But while we thus seek instruction in the pheno-
mena of the present state of things, we are led to the
question, What are the limits of this 'present' period?
For instance, among the currents of lava which we
trace as part of the shores of Italy and Sicily, which
shall we select as belonging to the existing order of
things? In going backwards in time, where shall we
draw the line? and why at such particular point?
These questions are important, for our estimate of the
efficacy of known causes will vary with the extent of
the effects which we ascribe to them. Hence the mode
in which we group together rocks is not only a step in
geological classification, but is also important to Ætio-
logy. Thus, when the vast masses of trap rocks in the
Western Isles of Scotland and in other countries, which
had been maintained by the Wernerians to be of aque-
ous origin, were, principally by the sagacity and in-
dustry of Macculloch, identified as to their nature with
the products of recent volcanoes, the amount of effect
which might justifiably be ascribed to volcanic agency
was materially extended.
In other cases, instead of observing the current
effects of our geological causes, we have to estimate the
results from what we know of the causes themselves;
as when, with Herschel, we calculate the alterations
in the temperature of the earth which astronomical
changes may possibly produce; or when, with Fourier,
we try to calculate the rate of cooling of the earth's
MEMBERS OF A PALETIOLOGICAL SCIENCE. 279
surface, on the hypothesis of an incandescent central
mass. In other cases, again, we are not able to cal-
culate the effects of our causes rigorously, but estimate
them as well as we can; partly by physical reasonings,
and partly by comparison with such analogous cases as
we can find in the present state of things. Thus Sir
Charles Lyell infers the change of climate which would
result if land were transferred from the neighbourhood
of the poles to that of the equator, by reasonings on the
power of land and water to contain and communicate
heat, supported by a reference to the different actual
climates of places, lying under the same latitude, but
under different conditions as to the distribution of
land and water.
Thus our Ætiology is constructed partly from calcu-
lation and reasoning, partly from phenomena. But we
may observe that when we reason from phenomena to
causes, we usually do so by various steps; often ascend-
ing from phenomena to mere laws of phenomena, before
we can venture to connect the phenomenon confidently
with its cause. Thus the law of subterranean heat,
that it increases in descending below the surface, is
now well established, although the doctrine which
ascribes this effect to a central heat is not universally
assented to.
14. In the Geography of Plants and Animals.—
We may find in other subjects also, considerable con-
tributions towards Etiology, though not as yet a com-
plete System of Science. The Etiology of Vegetables
and Animals, indeed, has been studied with great zeal
in modern times, as an essential preparative to geolo-
gical theory; for how can we decide whether any
assumed causes have produced the succession of species
which we find in the earth's strata, except we know
what effect of this kind given causes can produce?
Accordingly, we find in Sir Charles Lyell's Treatise on
Geology the most complete discussion of such questions
as belong to these subjects:-for example, the question
whether species can be transmuted into other species
by the long-continued influence of external causes, as
climate, food, domestication, combined with internal
280
PHILOSOPHY OF PALETIOLOGY,
causes, as habits, appetencies, progressive tendencies.
We may observe, too, that as we have, brought before
us, the inquiry what change difference of climate can
produce in any species, we have also the inverse prob-
lem, how far a different development of the species, or
a different collection of species, proves a difference of
climate. In the same way, the geologist of the present
day considers the question, whether, in virtue of causes
now in action, species are from time to time extin-
guished; and in like manner, the geologists of an
earlier period discussed the question, now long com-
pletely decided, whether fossil species in general are
really extinct species.
15. In Languages. Even with reference to the
Etiology of Language, although this branch of science
has hardly been considered separately from the glosso-
logical investigations in which it is employed or as-
sumed to be employed, it might perhaps be possible
to point out causes or conditions of change which,
being general in their nature, must operate upon all
languages alike. Changes made for the sake of euphony
when words are modified and combined, occur in all
dialects. Who can doubt that such changes of conso-
nants as those by which the Greek roots become Gothic,
and the Gothic, German, have for their cause some
general principle in the pronunciation of each lan-
guage? Again, we might attempt to decide other
questions of no small interest. Have the terminations
of verbs arisen from the accretion of pronouns; or, on
the other hand, does the modification of a verb imply
a simpler mental process than the insulation of a pro-
noun, as Adam Smith has maintained? Again, when
the language of a nation is changed by the invasion
and permanent mixture of an enemy of different speech,
is it generally true that it is changed from a synthetic
to an analytical structure? I will mention only one
more of these wide and general glossological inquiries.
Is it true, as Dr. Prichard has suggested', that lan-
guages have become more permanent as we come down
7 Researches, ii. 221.
MEMBERS OF A PALETIOLOGICAL SCIENCE. 281
towards later times? May we justifiably suppose, with
him, that in the very earliest times, nations, when
they had separated from one stock, might lose all
traces of this common origin out of their languages,
though retaining strong evidences of it in their mytho-
logy, social forms, and arts, as appears to be the case
with the ancient Egyptians and the Indians³.
Large questions of this nature cannot be treated
profitably in any other way than by an assiduous study
of the most varied forms of living and dead languages.
But on the other hand, the study of languages should
be prosecuted not only by a direct comparison of one
with another, but also with a view to the formation
of a science of causes and general principles, embracing
such discussions as I have pointed out.
It is only
when such a science has been formed, that we can hope
to obtain any solid and certain results in the Palætio-
logy of Language;—to determine, with any degree of
substantial proof, what is the real evidence which the
wonderful faculty of speech, under its present develop-
ments and forms, bears to the events which have taken
place in its own history, and in the history of man
since his first origin.
16. Construction of Theories.—When we have thus
obtained, with reference to any such subject as those
we have here spoken of, these two portions of science,
a Systematic Description of the Facts, and a rigorous
Analysis of the Causes,-the Phenomenology and the
Etiology of the subject,—we are prepared for the third
member which completes the science, the Theory of the
actual facts. We can then take a view of the events
which really have happened, discerning their con-
nexion, interpreting their evidence, supplying from
the context the parts which are unapparent. We
can account for known facts by intelligible causes;
we can infer latent facts from manifest effects, so as
to obtain a distinct insight into the whole history of
events up to the present time, and to see the last re-
sult of the whole in the present condition of things.
8 Researches, ii. 192.
282
PHILOSOPHY OF PALETIOLOGY.
The term Theory, when rigorously employed in such
sciences as those which we here consider, bears nearly
the sense which I have adopted: it implies a consistent
and systematic view of the actual facts, combined with
a true apprehension of their connexion and causes.
Thus if we speak of 'a Theory of Mount Etna,' or
'a Theory of the Paris Basin,' we mean a connected
and intelligible view of the events by which the rocks
in these localities have come into their present con-
dition. Undoubtedly the term Theory has often been
used in a looser sense; and men have put forth ‘Theo-
ries of the Earth,' which, instead of including the whole
mass of actual geological facts and their causes, only
assigned, in a vague manner, some causes by which
some few phenomena might, it was conceived, be ac-
counted for. Perhaps the portion of our Palætiological
Sciences which we now wish to designate, would be
more generally understood if we were to describe it as
Theoretical or Philosophical History; as when we talk
of 'the Theoretical History of Architecture,' or 'the
Philosophical History of Language.' And in the same
manner we might speak of the Theoretical History of
the Animal and Vegetable Kingdoms; meaning, a dis-
tinct account of the events which have produced the
present distribution of species and families. But by
whatever phrase we describe this portion of science, it
is plain that such a Theory, such a Theoretical His-
tory, must result from the application of causes well
understood to facts well ascertained. And if the term
Theory be here employed, we must recollect that it is
to be understood, not in its narrower sense as opposed
to facts, but in its wider signification, as including all
known facts and differing from them only in intro-
ducing among them principles of intelligible connexion.
The Theories of which we now speak are true Theories,
precisely because they are identical with the total sys-
tem of the Facts.
17. No sound Palatiological Theory yet extant.-
It is not to disparage unjustly the present state of
science, to say that as yet no such theory exists on
any subject.
"Theories of the Earth' have been re-
MEMBERS OF A PALETIOLOGICAL SCIENCE. 283
peatedly published; but when we consider that even
the facts of geology have been observed only on a small
portion of the earth's surface, and even within those
narrow bounds very imperfectly studied, we shall be
able to judge how impossible it is that geologists should
have yet obtained a well-established Theoretical His-
tory of the changes which have taken place in the
crust of the terrestrial globe from its first origin. Ac-
cordingly, I have ventured in my History to designate
the most prominent of the Theories which have hither-
to prevailed as premature geological theories: and we
shall soon see that geological theory has not advanced
beyond a few conjectures, and that its cultivators are
at present mainly occupied with a controversy in which
the two extreme hypotheses which first offer themselves
to men's minds are opposed to each other. And if we
have no theoretical History of the Earth which merits
any confidence, still less have we any theoretical His-
tory of Language, or of the Arts, which we can con-
sider as satisfactory. The Theoretical History of the
Vegetable and Animal Kingdoms is closely connected
with that of the Earth on which they subsist, and must
follow the fortunes of Geology. And thus we may
venture to say that no Palætiological Science, as yet,
possesses all its three members. Indeed most of them
are very far from having completed and systematized
their Phenomenology: in all, the cultivation of Ætio-
logy is but just begun, or is not begun; in all, the
Theory must reward the exertions of future, probably
of distant, generations.
But in the mean time we may derive some instruc-
tion from the comparison of the two antagonist hypo-
theses of which I have spoken.
9 Hist. Ind. Sc. b. xviii. c. vii. sect. 3.
CHAPTER III.
OF THE DOCTRINE OF CATASTROPHES AND THE DOC-
TRINE OF UNIFORMITY.
1. Doctrine of Catastrophes.-I HAVE already shown,
in the History of Geology, that the attempts to frame
a theory of the earth have brought into view two com-
pletely opposite opinions:-one, which represents the
course of nature as uniform through all ages, the
causes which produce change having had the same
intensity in former times which they have at the pre-
sent day;-the other opinion, which sees, in the pre-
sent condition of things, evidences of catastrophes;
changes of a more sweeping kind, and produced by
more powerful agencies than those which occur in re-
cent times. Geologists who held the latter opinion,
maintained that the forces which have elevated the
Alps or the Andes to their present height could not
have been any forces which are now in action: they
pointed to vast masses of strata hundreds of miles long,
thousands of feet thick, thrown into highly-inclined
positions, fractured, dislocated, crushed: they remarked
that upon the shattered edges of such strata they found
enormous accumulations of fragments and rubbish,
rounded by the action of water, so as to denote ages
of violent aqueous action: they conceived that they
saw instances in which whole mountains of rock in a
state of igneous fusion, must have burst the earth's crust
from below: they found that in the course of the re-
volutions by which one stratum of rock was placed
upon another, the whole collection of animal species
which tenanted the earth and the seas had been re-
moved, and a new set of living things introduced in
its place: finally, they found, above all the strata,
DOCTRINES OF CATASTROPHES, ETC. 285
vast masses of sand and gravel containing bones of
animals, and apparently the work of a mighty deluge.
With all these proofs before their eyes, they thought
it impossible not to judge that the agents of change by
which the world was urged from one condition to
another till it reached its present state must have been
more violent, more powerful, than any which we see at
work around us. They conceived that the evidence of
'catastrophes' was irresistible.
2. Doctrine of Uniformity.—I need not here re-
peat the narrative (given in the History') of the
process by which this formidable array of proofs was,
in the minds of some eminent geologists, weakened,
and at last overcome. This was done by showing that
the sudden breaks in the succession of strata were
apparent only, the discontinuity of the series which
occurred in one country being removed by terms
interposed in another locality:-by urging that the
total effect produced by existing causes, taking into
account the accumulated result of long periods, is far
greater than a casual speculator would think possible:
-by making it appear that there are in many parts of
the world evidences of a slow and imperceptible rising
of the land since it was the habitation of now exist-
ing species-by proving that it is not universally
true that the strata separated in time by supposed
catastrophes contain distinct species of animals:-by
pointing out the limited fields of the supposed diluvial
action-and finally, by remarking that though the
creation of species is a mystery, the extinction of
species is going on in our own day. Hypotheses were
suggested, too, by which it was conceived that the
change of climate might be explained, which, as the
consideration of the fossil remains seemed to show,
must have taken place between the ancient and the
modern times. In this manner the whole evidence of
catastrophes was explained away: the notion of a
series of paroxysms of violence in the causes of change
was represented as a delusion arising from our contem-
1 Hist. Ind. Sc. b. xviii. c. viii. sect. 2.
286
PHILOSOPHY OF PALÆTIOLOGY.
plating short periods only, in the action of present
causes: length of time was called in to take the place
of intensity of force: and it was declared that Geology
need not despair of accounting for the revolutions of
the earth, as Astronomy accounts for the revolutions
of the heavens, by the universal action of causes
which are close at hand to us, operating through time
and space without variation or decay.
An antagonism of opinions, somewhat of the same
kind as this, will be found to manifest itself in the
other Palætiological Sciences as well as in Geology;
and it will be instructive to endeavour to balance these
opposite doctrines. I will mention some of the con-
siderations which bear upon the subject in its general
form.
3. Is Uniformity probable à priori ?-The doctrine
of Uniformity in the course of nature has sometimes
been represented by its adherents as possessing a great
degree of à priori probability. It is highly unphiloso-
phical, it has been urged, to assume that the causes of
the geological events of former times were of a different
kind from causes now in action, if causes of this latter
kind can in any way be made to explain the facts.
The analogy of all other sciences compels us, it was
said, to explain phenomena by known, not by unknown,
causes. And on these grounds the geological teacher
recommended an earnest and patient endeavour to
reconcile the indications of former change with the
evidence of gradual mutations now in progress.'
But on this we may remark, that if by known
causes we mean causes acting with the same intensity
which they have had during historical times, the re-
striction is altogether arbitrary and groundless. Let
it be granted, for instance, that many parts of the
earth's surface are now undergoing an imperceptible
rise. It is not pretended that the rate of this eleva-
tion is rigorously uniform; what, then, are the limits
of its velocity? Why may it not increase so as to as-
sume that character of violence which we may term a
2 Lyell, 4th ed. b. iv. c. i. p. 328.
DOCTRINES OF CATASTROPHES, ETC.
287
catastrophe with reference to all changes hitherto re-
corded? Why may not the rate of elevation be such
that we may conceive the strata to assume suddenly
a position nearly vertical? And is it, in fact, easy to
conceive a position of strata nearly vertical, a position
which occurs so frequently, to be gradually assumed?
In cases where the strata are nearly vertical, as in the
Isle of Wight, and hundreds of other places, or where
they are actually inverted, as sometimes occurs, are not
the causes which have produced the effect as truly
known causes, as those which have raised the coasts
where we trace the former beach in an elevated
terrace? If the latter case proves slow elevation, does
not the former case prove rapid elevation? In neither
case have we any measure of the time employed in the
change; but does not the very nature of the results
enable us to discern, that if one was gradual, the other
was comparatively sudden?
The causes which are now elevating a portion of
Scandinavia can be called known causes, only because
we know the effect. Are not the causes which have
elevated the Alps and the Andes known causes in the
same sense? We know nothing in either case which
confines the intensity of the force within any limit, or
prescribes to it any law of uniformity. Why, then,
should we make a merit of cramping our speculations
by such assumptions? Whether the causes of change
do act uniformly ;-whether they oscillate only within
narrow limits;-whether their intensity in former
times was nearly the same as it now is;-these are
precisely the questions which we wish Science to an-
swer to us impartially and truly: where is then the
wisdom of 'an earnest and patient endeavour' to secure
an affirmative reply?
Thus I conceive that the assertion of an à priori
claim to probability and philosophical spirit in favour
of the doctrine of uniformity, is quite untenable.
We
must learn from an examination of all the facts, and
not from any assumption of our own, whether the
course of nature be uniform. The limit of intensity
being really unknown, catastrophes are just as probable
288 PHILOSOPHY OF PALÆTIOLOGY.
as uniformity. If a volcano may repose for a thousand
years, and then break out and destroy a city; why
may not another volcano repose for ten thousand
years, and then destroy a continent; or if a continent,
why not the whole habitable surface of the earth?
4. Cycle of Uniformity indefinite.-But this argu-
ment may be put in another form. When it is said
that the course of nature is uniform, the assertion is
not intended to exclude certain smaller variations of
violence and rest, such as we have just spoken of;—
alternations of activity and repose in volcanoes; or
earthquakes, deluges, and storms, interposed in a more
tranquil state of things. With regard to such occur-
rences, terrible as they appear at the time, they may
not much affect the average rate of change; there may
be a cycle, though an irregular one, of rapid and slow
change; and if such cycles go on succeeding each other,
we may still call the order of nature uniform, notwith-
standing the periods of violence which it involves.
The maximum and minimum intensities of the forces
of mutation alternate with one another; and we may
estimate the average course of nature as that which
corresponds to something between the two extremes.
But if we thus attempt to maintain the uniformity
of nature by representing it as a series of cycles,
we find that we cannot discover, in this conception,
any solid ground for excluding catastrophes. What is
the length of that cycle, the repetition of which con-
stitutes uniformity? What interval from the maximum
to the minimum does it admit of? We may take for
our cycle a hundred or a thousand years, but evidently
such a proceeding is altogether arbitrary. We may
mark our cycles by the greatest known paroxysms of
volcanic and terremotive agency, but this procedure is
no less indefinite and inconclusive than the other.
But further; since the cycle in which violence and
repose alternate is thus indefinite in its length and in
its range of activity, what ground have we for as-
suming more than one such cycle, extending from the
origin of things to the present time? Why may we
not suppose the maximum force of the causes of change
DOCTRINES OF CATASTROPHES, ETC. 289
to have taken place at the earliest period, and the ten-
dency towards the minimum to have gone on ever
since? Or instead of only one cycle, there may have
been several, but of such length that our historical
period forms a portion only of the last;—the feeblest
portion of the latest cycle. And thus violence and
repose may alternate upon a scale of time and intensity
so large, that man's experience supplies no evidence
enabling him to estimate the amount. The course of
things is uniform, to an Intelligence which can embrace
the succession of several cycles, but it is catastrophic
to the contemplation of man, whose survey can grasp a
part only of one cycle. And thus the hypothesis of
uniformity, since it cannot exclude degrees of change,
nor limit the range of these degrees, nor define the
interval of their recurrence, cannot possess any essen-
tial simplicity which, previous to inquiry, gives it a
claim upon our assent superior to that of the opposite
catastrophic hypothesis.
5. Uniformitarian Arguments are Negative only.—
There is an opposite tendency in the mode of main-
taining the catastrophist and the uniformitarian opi-
nions, which depends upon their fundamental prin-
ciples, and shows itself in all the controversies between
them. The Catastrophist is affirmative, the Uniformi-
tarian is negative in his assertions: the former is con-
stantly attempting to construct a theory; the latter
delights in demolishing all theories. The one is con-
stantly bringing fresh evidence of some great past
event, or series of events, of a striking and definite
kind; his antagonist is at every step explaining away
the evidence, and showing that it proves nothing. One
geologist adduces his proofs of a vast universal deluge;
but another endeavours to show that the proofs do
not establish either the universality or the vastness of
such an event. The inclined broken edges of a certain
formation, covered with their own fragments, beneath
superjacent horizontal deposits, are at one time sup-
posed to prove a catastrophic breaking up of the earlier
strata; but this opinion is controverted by showing that
the same formations, when pursued into other countries,
VOL. II.
U
290
PHILOSOPHY OF PALETIOLOGY.
exhibit a uniform gradation from the lower to the
upper, with no trace of violence. Extensive and lofty
elevations of the coast, continents of igneous rock, at
first appear to indicate operations far more gigantic
than those which now occur; but attempts are soon
made to show that time only is wanting to enable the
present age to rival the past in the production of such
changes. Each new fact adduced by the catastrophist
is at first striking and apparently convincing; but as it
becomes familiar, it strikes the imagination less power-
fully; and the uniformitarian, constantly labouring to
produce some imitation of it by the machinery which
he has so well studied, at last in every case seems to
himself to succeed, so far as to destroy the effect of his
opponent's evidence.
This is so with regard to more remote, as well as
with regard to immediate evidences of change. When
it is ascertained that in every part of the earth's crust
the temperature increases as we descend below the
surface, at first this fact seems to indicate a central
heat and a central heat naturally suggests an earlier
state of the mass, in which it was incandescent, and
from which it is now cooling. But this original incan-
descence of the globe of the earth is manifestly an
entire violation of the present course of things; it
belongs to the catastrophist view, and the advocates
of uniformity have to explain it away. Accordingly,
one of them holds that this increase of heat in descend-
ing below the surface may very possibly not go on all
the way to the center. The heat which increases at
first as we descend, may, he conceives, afterwards
decrease; and he suggests causes which may have pro-
duced such a succession of hotter and colder shells
within the mass of the earth. I have mentioned this
suggestion in the History of Geology; and have given.
my reasons for believing it altogether untenable³.
Other persons also, desirous of reconciling this sub-
terraneous heat with the tenet of uniformity, have
3 Hist. Ind. Sc. b. xviii. c. v. sect. 5, and note.
DOCTRINES OF CATASTROPHES, ETC. 291
offered another suggestion:-that the warmth or in-
candescence of the interior parts of the earth does not
arise out of an originally hot condition from which it
is gradually cooling, but results from chemical action
constantly going on among the materials of the earth's
substance. And thus new attempts are perpetually
making, to escape from the cogency of the reasonings
which send us towards an original state of things dif-
ferent from the present. Those who theorize concern-
ing an origin go on building up the fabric of their
speculations, while those who think such theories un-
philosophical, ever and anon dig away the foundation
of this structure. As we have already said, the uni-
formitarian's doctrines are a collection of negatives.
This is so entirely the case, that the uniformitarian
would for the most part shrink from maintaining as
positive tenets the explanations which he so willingly
uses as instruments of controversy. He puts forward
his suggestions as difficulties, but he will not stand by
them as doctrines. And this is in accordance with his
general tendency; for any of his hypotheses, if insisted
upon as positive theories, would be found inconsistent
with the assertion of uniformity. For example, the
nebular hypothesis appears to give to the history of
the heavens an aspect which obliterates all special acts
of creation, for, according to that hypothesis, new
planetary systems are constantly forming; but when
asserted as the origin of our own solar system, it
brings with it an original incandescence, and an origin
of the organic world. And if, instead of using the
chemical theory of subterraneous heat to neutralize the
evidence of original incandescence, we assert it as a
positive tenet, we can no longer maintain the infinite
past duration of the earth; for chemical forces, as well
as mechanical, tend to equilibrium; and that condition
once attained, their efficacy ceases. Chemical affinities
tend to form new compounds; and though, when many
and various elements are mingled together, the play of
synthesis and analysis may go on for a long time, it
must at last end. If, for instance, a large portion of
the earth's mass were originally pure potassium, we
U 2
292
PHILOSOPHY OF PALETIOLOGY.
!
can imagine violent igneous action to go on so long as
any part remained unoxidized; but when the oxida-
tion of the whole has once taken place, this action
must be at an end; for there is in the hypothesis
no agency which can reproduce the deoxidized metal.
Thus a perpetual motion is impossible in chemistry, as
it is in mechanics; and a theory of constant change
continued through infinite time, is untenable when
asserted upon chemical, no less than upon mechanical
principles. And thus the Skepticism of the unifor-
mitarian is of force only so long as it is employed
against the Dogmatism of the catastrophist. When
the Doubts are erected into Dogmas, they are no
longer consistent with the tenet of Uniformity. When
the Negations become Affirmations, the Negation of an
Origin vanishes also.
6. Uniformity in the Organic World.-In speaking
of the violent and sudden changes which constitute
catastrophes, our thoughts naturally turn at first to
great mechanical and physical effects;-ruptures and
displacements of strata; extensive submersions and
emersions of land; rapid changes of temperature. But
the catastrophes which we have to consider in geology
affect the organic as well as the inorganic world. The
sudden extinction of one collection of species, and the
introduction of another in their place, is a Catastrophe,
even if unaccompanied by mechanical violence. Ac-
cordingly, the antagonism of the catastrophist and
uniformitarian schools has shown itself in this depart-
ment of the subject, as well as in the other. When
geologists had first discovered that the successive strata
are each distinguished by appropriate organic fossils,
they assumed at once that each of these collections of
living things belonged to a separate creation. But
this conclusion, as I have already said, Sir C. Lyell has
attempted to invalidate, by proving that in the exist-
ing order of things, some species become extinct; and
by suggesting it as possible, that in the same order, it
may be true that new species are from time to time
produced, even in the present course of nature. And
in this, as in the other part of the subject, he calls in
DOCTRINES OF CATASTROPHES, ETC. 293
the aid of vast periods of time, in order that the vio-
lence of the changes may be softened down: and he
appears disposed to believe that the actual extinction
and creation of species may be so slow as to excite no
more notice than it has hitherto obtained; and yet may
be rapid enough, considering the immensity of geologi-
cal periods, to produce such a succession of different
collections of species as we find in the strata of the
earth's surface.
7. Origin of the present Organic World.-The last
great event in the history of the vegetable and animal
kingdoms was that by which their various tribes were
placed in their present seats. And we may form
various hypotheses with regard to the sudden or gra-
dual manner in which we may suppose this distribution
to have taken place. We may assume that at the be-
ginning of the present order of things, a stock of each
species was placed in the vegetable or animal province
to which it belongs, by some cause out of the com-
mon order of nature; or we may take a uniformi-
tarian view of the subject, and suppose that the pro-
vinces of the organic world derived their population
from some anterior state of things by the operation of
natural causes.
•
Nothing has been pointed out in the existing order
of things which has any analogy or resemblance, of
any valid kind, to that creative energy which must be
exerted in the production of a new species. And to
assume the introduction of new species as 'a part of
the order of nature,' without pointing out any natural
fact with which such an event can be classed, would
be to reject creation by an arbitrary act. Hence,
even on natural grounds, the most intelligible view of
the history of the animal and vegetable kingdoms
seems to be, that each period which is marked by a
distinct collection of species forms a cycle; and that at
the beginning of each such cycle a creative power was
exerted, of a kind to which there was nothing at all
analogous in the succeeding part of the same cycle. If
it be urged that in some cases the same species, or the
same genus, runs through two geological formations,
294
PHILOSOPHY OF PALÆTIOLOGY.
which must, on other grounds, be referred to different
cycles of creative energy, we may reply that the crea-
tion of many new species does not imply the extinction
of all the old ones.
Thus we are led by our reasonings to this view, that
the present order of things was commenced by an act
of creative power entirely different to any agency which
has been exerted since. None of the influences which
have modified the present races of animals and plants
since they were placed in their habitations on the
earth's surface can have had any efficacy in producing
them at first. We are necessarily driven to assume,
as the beginning of the present cycle of organic na-
ture, an event not included in the course of nature.
And we may remark that this necessity is the more
cogent, precisely because other cycles have preceded
the present.
8. Nebular Origin of the Solar System.-If we
attempt to apply the same antithesis of opinion (the
doctrines of Catastrophe and Uniformity) to the other
subjects of palætiological sciences, we shall be led to
similar conclusions. Thus, if we turn our attention to
Astronomical Palætiology, we perceive that the Nebu-
lar Hypothesis has a uniformitarian tendency. Accord-
ing to this hypothesis the formation of this our system
of sun, planets, and satellites, was a process of the same
kind as those which are still going on in the heavens.
One after another, nebula condensc into separate
masses, which begin to revolve about each other by
mechanical necessity, and form systems of which our
solar system is a finished example. But we may re-
mark, that the uniformitarian doctrine on this subject
rests on most unstable foundations. We have as yet
only very vague and imperfect reasonings to show that
by such condensation a material system such as ours
could result; and the introduction of organized beings
into such a material system is utterly out of the reach
of our philosophy. Here again, therefore, we are led
to regard the present order of the world as pointing
towards an origin altogether of a different kind from
anything which our material science can grasp.
DOCTRINES OF CATASTROPHES, ETC. 295
9. Origin of Languages.-We may venture to say
that we should be led to the same conclusion once
more, if we were to take into our consideration those
palætiological sciences which are beyond the domain of
matter; for instance, the History of Languages. We
may explain many of the differences and changes which
we become acquainted with, by referring to the action
of causes of change which still operate. But what
glossologist will venture to declare that the efficacy of
such causes has been uniform;-that the influences
which mould a language, or make one language differ
from others of the same stock, operated formerly with
no more efficacy than they exercise now. 'Where,'
as has elsewhere been asked, 'do we now find a lan-
guage in the process of formation, unfolding itself in
inflexions, terminations, changes of vowels by gram-
matical relations, such as characterise the oldest known
languages?' Again, as another proof how little the
history of languages suggests to the philosophical glosso-
logist the persuasion of a uniform action of the causes
of change, I may refer to the conjecture of Dr. Pri-
chard, that the varieties of language produced by the
separation of one stock into several, have been greater
and greater as we go backwards in history :-that the
formation of sister dialects from a common language
(as the Scandinavian, German, and Saxon dialects from
the Teutonic, or the Gaelic, Erse and Welsh from the
Celtic) belongs to the first millennium before the
Christian era; while the formation of cognate lan-
guages of the same family, as the Sanskrit, Latin,
Greek and Gothic, must be placed at least two thou-
sand years before that era; and at a still earlier period
took place the separation of the great families them-
selves, the Indo-European, Semitic, and others, in
which it is now difficult to trace the features of a
common origin. No hypothesis except one of this
kind will explain the existence of the families, groups,
and dialects of languages, which we find in existence.
Yet this is an entirely different view from that which
4 Researches, ii. 224.
296
PHILOSOPHY OF PALETIOLOGY.
.
the hypothesis of the uniform progress of change would
give. And thus, in the earliest stages of man's career,
the revolutions of language must have been, even by
the evidence of the theoretical history of language
itself, of an order altogether different from any which
have taken place within the recent history of man.
And we may add, that as the early stages of the pro-
gress of language must have been widely different from
those later ones of which we can in some measure trace
the natural causes, we cannot place the origin of lan-
guage in any point of view in which it comes under
the jurisdiction of natural causation at all.
10. No Natural Origin discoverable.—We are thus
led by a survey of several of the palatiological sciences
to a confirmation of the principle formerly asserted³,
That in no palætiological science has man been able to
arrive at a beginning which is homogeneous with the
known course of events. We
e can in such sciences
often go very far back;-determine many of the re-
mote circumstances of the past series of events;—ascend
to a point which seems to be near the origin ;—and
limit the hypotheses respecting the origin itself: but
philosophers never have demonstrated, and, so far as
we can judge, probably never will be able to demon-
strate, what was that primitive state of things from
which the progressive course of the world took its first
departure. In all these paths of research, when we
travel far backwards, the aspect of the earlier portions
becomes very different from that of the advanced part
on which we now stand; but in all cases the path is
lost in obscurity as it is traced backwards towards its
starting-point: it becomes not only invisible, but un-
imaginable; it is not only an interruption, but an
abyss, which interposes itself between us and any in-
telligible beginning of things.
7
!
5 Hist. Ind. Sc. b. xviii. c. vi. sect 5.
CHAPTER IV.
OF THE RELATION OF TRADITION TO PALETIOLOGY.
All
1. Importance of Tradition.-SINCE the Palætio-
logical Sciences have it for their business to study
the train of past events produced by natural causes
down to the present time, the knowledge concern-
ing such events which is supplied by the remem-
brance and records of man, in whatever form, must
have an important bearing upon these sciences.
changes in the condition and extent of land and
sea, which have taken place within man's observation,
all effects of deluges, sea-waves, rivers, springs, volca-
noes, earthquakes, and the like, which come within the
reach of human history, have a strong interest for the
palætiologist. Nor is he less concerned in all re-
corded instances of the modification of the forms and
habits of plants and animals, by the operations of man,
or by transfer from one land to another. And when
we come to the Palætiology of Language, of Art, of
Civilization, we find our subject still more closely con-
nected with history; for in truth these are historical,
no less than palætiological investigations. But, con-
fining ourselves at present to the material sciences, we
may observe that though the importance of the infor-
mation which tradition gives us, in the sciences now
under our consideration, as, for instance, geology, has
long been tacitly recognised; yet it is only recently
that geologists have employed themselves in collecting
their historical facts upon such a scale and with such
comprehensive views as are required by the interest
and use of collections of this kind. The Essay of Von
298
PHILOSOPHY OF PALETIOLOGY.
Hoff', On the Natural Alterations in the Surface of the
Earth which are proved by Tradition, was the work
which first opened the eyes of geologists to the extent
and importance of this kind of investigation. Since
that time the same path of research has been pursued
with great perseverance by others, especially by Sir
C. Lyell; and is now justly considered as an essential
portion of Geology.
2. Connexion of Tradition and Science.-Events
which we might naturally expect to have some bearing
on geology, are narrated in the historical writings
which, even on mere human grounds, have the
strongest claim to our respect as records of the early
history of the world, and are confirmed by the tradi-
tions of various nations all over the globe; namely,
the formation of the earth and of its population, and a
subsequent deluge. It has been made a matter of con-
troversy how the narrative of these events is to be
understood, so as to make it agree with the facts which
an examination of the earth's surface and of its vege-
table and animal population discloses to us. Such
controversies, when they are considered as merely
archæological, may occur in any of the palatiological
sciences. We may have to compare and to reconcile
the evidence of existing phenomena with that of
historical tradition. But under some circumstances
this process of conciliation may assume an interest of
another kind, ou which we will make a few remarks.
3. Natural and Providential History of the World.
-We may contemplate the existence of man upon the
earth, his origin and his progress, in the same manner
as we contemplate the existence of any other race of
animals; namely, in a purely palætiological view. We
may consider how far our knowledge of laws of causa-
tion enables us to explain his diffusion and migration,
his differences and resemblances, his actions and works.
And this is the view of man as a member of the
Natural Course of Things.
1 Vol. i. 1822; vol. ii. 1824.
RELATION OF TRADITION TO PALETIOLOGY. 299
But man, at the same time the contemplator and
the subject of his own contemplation, endowed with
faculties and powers which make him a being of a
different nature from other animals, cannot help re-
garding his own actions and enjoyments, his recollec-
tions and his hopes, under an aspect quite different
from any that we have yet had presented to us.
We
have been endeavouring to place in a clear light the
Fundamental Ideas, such as that of Cause, on which
depends our knowledge of the natural course of things.
But there are other Ideas to which man necessarily
refers his actions; he is led by his nature, not only to
consider his own actions, and those of his fellow-men,
as springing out of this or that cause, leading to this
or that material result; but also as good or bad, as
what they ought or ought not to be. He has Ideas
of moral relations as well as those Ideas of material
relations with which we have hitherto been occupied.
He is a moral as well as a natural agent.
Contemplating himself and the world around him
by the light of his Moral Ideas, man is led to the con-
viction that his moral faculties were bestowed upon him
by design and for a purpose; that he is the subject of
a Moral Government; that the course of the world is
directed by the Power which governs it, to the un-
folding and perfecting of man's moral nature; that this
guidance may be traced in the career of individuals
and of the world; that there is a Providential as well
as a Natural Course of Things.
Yet this view is beset by no small difficulties. The
full development of man's moral faculties;—the per-
fection of his nature up to the measure of his own
ideas; the adaptation of his moral being to an ultimate
destination, by its transit through a world full of moral
evil, in which evil each person has his share;—are
effects for which the economy of the world appears to
contain no adequate provision. Man, though aware of
his moral nature, and ready to believe in an ultimate
destination of purity and blessedness, is too feeble to
resist the temptation of evil, and too helpless to restore
his purity when once lost. He cannot but look for
300
PHILOSOPHY OF PALÆTIOLOGY.
some confirmation of that providential order which he
has begun to believe; some provision for those defici-
encies in his moral condition which he has begun to feel.
He looks at the history of the world, and he finds
that at a certain period it offers to him the promise of
what he seeks. When the natural powers of man had
been developed to their full extent, and were beginning
to exhibit symptoms of decay;-when the intellectual
progress of the world appeared to have reached its
limit, without supplying man's moral needs;—we find
the great Epoch in the Providential History of the
world. We find the announcement of a Dispensation
by which man's deficiencies shall be supplied and his
aspirations fulfilled: we find a provision for the purifi-
cation, the support, and the ultimate beatification of
those who use the provided means. And thus the
providential course of the world becomes consistent
and intelligible.
4. The Sacred Narrative.—But with the new Dis-
pensation, we receive, not only an account of its own
scheme and history, but also a written narrative of
the providential course of the world from the earliest
times, and even from its first creation. This narrative
is recognized and authorized by the new dispensation,
and accredited by some of the same evidences as the
dispensation itself. That the existence of such a sacred
narrative should be a part of the providential order
of things, cannot but appear natural; but, naturally
also, the study of it leads to some difficulties.
The Sacred Narrative in some of its earliest portions
speaks of natural objects and occurrences respecting
them. In the very beginning of the course of the
world, we may readily believe (indeed, as we have seen
in the last chapter, our scientific researches lead us to
believe) that such occurrences were very different from
anything which now takes place;-different to an
extent and in a manner which we cannot estimate.
Now the narrative must speak of objects and occur-
rences in the words and phrases which have derived
their meaning from their application to the existing
natural state of things. When applied to an initial

RELATION OF TRADITION TO PALETIOLOGY. 301
supernatural state therefore, these words and phrases
cannot help being to us obscure and mysterious, perhaps
ambiguous and seemingly contradictory.
5. Difficulties in interpreting the Sacred Narrative.—
The moral and providential relations of man's condition
are so much more important to him than mere natural
relations, that at first we may well suppose he will
accept the Sacred Narrative, as not only unquestion-
able in its true import, but also as a guide in his views
even of mere natural things. He will try to modify
the conceptions which he entertains of objects and
their properties, so that the Sacred Narrative of the
supernatural condition shall retain the first meaning
which he had put upon it in virtue of his own habits
in the usage of language.
But man is so constituted that he cannot persist in
this procedure. The powers and tendencies of his in-
tellect are such that he cannot help trying to attain true
conceptions of objects and their properties by the study
of things themselves. For instance, when he at first
read of a firmament dividing the waters above from the
waters below, he perhaps conceived a transparent floor
in the skies, on which the superior waters rested, which
descend in rain; but as his observations and his reason-
ings satisfied him that such a floor could not exist, he
became willing to allow (as St. Augustine allowed) that
the waters above the firmament are in a state of vapour.
And in like manner in other subjects, men, as their
views of nature became more distinct and precise,
modified, so far as it was necessary for consistency's
sake, their first rude interpretations of the Sacred
Narrative; so that, without in any degree losing its
import as a view of the providential course of the
world, it should be so conceived as not to contradict
what they knew of the natural order of things.
But this accommodation was not always made with-
out painful struggles and angry controversies. When
men had conceived the occurrences of the Sacred Nar-
rative in a particular manner, they could not readily
and willingly adopt a new mode of conception; and all
attempts to recommend to them such novelties, they
302
PHILOSOPHY OF PALETIOLOGY.
resisted as attacks upon the sacredness of the Nar-
rative. They had clothed their belief of the workings
of Providence in certain images; and they clung to
those images with the persuasion that, without them,
their belief could not subsist. Thus they imagined to
themselves that the earth was a flat floor, solidly and
broadly laid for the convenience of man; and they felt
as if the kindness of Providence was disparaged, when
it was maintained that the earth was a globe held to-
gether only by the mutual attraction of its parts.
The most memorable instance of a struggle of this
kind is to be found in the circumstances which attended
the introduction of the Heliocentric Theory of Coper-
nicus to general acceptance. On this controversy I
have already made some remarks in the History of
Science, and have attempted to draw from it some
lessons which may be useful to us when any similar
conflict of opinions may occur. I will here add a few
reflections with a similar view.
6. Such difficulties inevitable.—In the first place, I
remark that such modifications of the current inter-
pretation of the words of Scripture appear to be an
inevitable consequence of the progressive character of
Natural Science. Science is constantly teaching us to
describe known facts in new language; but the lan-
guage of Scripture is always the same. And not only
so, but the language of Scripture is necessarily adapted
to the common state of man's intellectual development,
in which he is supposed not to be possessed of science.
Hence the phrases used by Scripture are precisely those
which science soon teaches man to consider as inaccu-
rate. Yet they are not, on that account, the less
fitted for their proper purpose: for if any terms had
been used, adapted to a more advanced state of know-
ledge, they must have been unintelligible among those
to whom the Scripture was first addressed. If the
Jews had been told that water existed in the clouds in
small drops, they would have marvelled that it did
2 B. v. c. iii. sect. 4.
RELATION OF TRADITION TO PALETIOLOGY. 303
not constantly descend; and to have explained the
reason of this, would have been to teach Atmology in
the sacred writings. If they had read in their Scrip-
ture that the earth was a sphere, when it appeared
to be a plain, they would only have been disturbed
in their thoughts or driven to some wild and base-
less imaginations, by a declaration to them so strange.
If the Divine Speaker, instead of saying that he would
set his bow in the clouds, had been made to declare
that he would give to water the property of refract-
ing different colours at different angles, how utterly
unmeaning to the hearers would the words have been !
And in these cases, the expressions, being unintelli-
gible, startling, and bewildering, would have been such
as tended to unfit the Sacred Narrative for its place in
the providential dispensation of the world.
Accordingly, in the great controversy which took
place in Galileo's time between the defenders of the
then customary interpretations of Scripture, and the
assertors of the Copernican system of the universe,
when the innovators were upbraided with maintain-
ing opinions contrary to Scripture, they replied that
Scripture was not intended to teach men astronomy,
and that it expressed the acts of divine power in
images which were suited to the ideas of unscientific
men. To speak of the rising and setting and travelling
of the sun, of the fixity and of the foundations of the
earth, was to use the only language which would have
made the Sacred Narrative intelligible. To extract
from these and the like expressions doctrines of sci-
ence, was, they declared, in the highest degree unjusti-
fiable; and such a course could lead, they held, to no
result but a weakening of the authority of Scripture
in proportion as its credit was identified with that of
these modes of applying it. And this judgment has
since been generally assented to by those who most
reverence and value the study of the designs of Provi-
dence as well as that of the works of nature.
7. Science tells us nothing concerning Creation.-
Other apparent difficulties arise from the accounts
given in the Scripture of the first origin of the world
304
PHILOSOPHY OF PALÆTIOLOGY.
in which we live: for example, Light is represented as
created before the Sun. With regard to difficulties of
this kind, it appears that we may derive some instruc-
tion from the result to which we were led in the last
chapter;—namely, that in the sciences which trace the
progress of natural occurrences, we can in no case go
back to an origin, but in every instance appear to find
ourselves separated from it by a state of things, and an
order of events, of a kind altogether different from
those which come under our experience. The thread
of induction respecting the natural course of the
world snaps in our fingers, when we try to ascertain
where its beginning is. Since, then, science can teach
us nothing positive respecting the beginning of things,
she can neither contradict nor confirm what is taught
by Scripture on that subject; and thus, as it is un-
worthy timidity in the lover of Scripture to fear con-
tradiction, so is it ungrounded presumption to look for
confirmation, in such cases. The providential history
of the world has its own beginning, and its own
evidence; and we can only render the system inse-
cure, by making it lean on our material sciences. If
any one were to suggest that the nebular hypothesis
countenances the Scripture history of the formation of
this system, by showing how the luminous matter of
the sun might exist previous to the sun itself, we
should act wisely in rejecting such an attempt to
weave together these two heterogeneous threads ;—the
one a part of a providential scheme, the other a frag-
ment of a physical speculation.
We shall best learn those lessons of the true philo-
sophy of science which it is our object to collect, by
attending to portions of science which have gone through
such crises as we are now considering; nor is it requi-
site, for this purpose, to bring forwards any subjects
which are still under discussion. It may, however, be
mentioned that such maxims as we are now endea-
vouring to establish, and the one before us in parti-
cular, bear with a peculiar force upon those Palætio-
logical Sciences of which we have been treating in the
present Book.
RELATION OF TRADITION TO PALETIOLOGY. 305
8. Scientific views, when familiar, do not disturb
the authority of Scripture.-There is another reflection
which may serve to console and encourage us in the
painful struggles which thus take place, between those
who maintain interpretations of Scripture already pre-
valent and those who contend for such new ones as the
new discoveries of science require. It is this;-that
though the new opinion is resisted by one party as
something destructive of the credit of Scripture and
the reverence which is its due, yet, in fact, when the
new interpretation has been generally established and
incorporated with men's current thoughts, it ceases to
disturb their views of the authority of the Scripture or
of the truth of its teaching. When the language of
Scripture, invested with its new meaning, has become
familiar to men, it is found that the ideas which it
calls up are quite as reconcileable as the former ones
were, with the most entire acceptance of the provi-
dential dispensation. And when this has been found
to be the case, all cultivated persons look back with
surprise at the mistake of those who thought that the
essence of the revelation was involved in their own
arbitrary version of some collateral circumstance in the
revealed narrative. At the present day, we can hardly
conceive how reasonable men could ever have imagined
that religious reflections on the stability of the earth,
and the beauty and use of the luminaries which revolve
round it, would be interfered with by an acknowledg-
ment that this rest and motion are apparent only³.
And thus the authority of revelation is not shaken by
any changes introduced by the progress of science in the
mode of interpreting expressions which describe phy-
sical objects and occurrences; provided the new in-
terpretation is admitted at a proper season, and in a
proper spirit; so as to soften, as much as possible, both
the public controversies and the private scruples which
almost inevitably accompany such an alteration.
9.
When should old Interpretations be given up?
But the question then occurs, What is the proper
3 I have here borrowed a sentence or two from my own History.
VOL. II.
X
306
PHILOSOPHY OF PALÆTIOLOGY.
season for a religious and enlightened commentator to
make such a change in the current interpretation of
sacred Scripture? At what period ought the esta-
blished exposition of a passage to be given up, and a
new mode of understanding the passage, such as is,
or seems to be, required by new discoveries respecting
the laws of nature, accepted in its place? It is plain,
that to introduce such an alteration lightly and hastily
would be a procedure fraught with inconvenience; for
if the change were made in such a manner, it might be
afterwards discovered that it had been adopted with-
out sufficient reason, and that it was necessary to
reinstate the old exposition. And the minds of the
readers of Scripture, always to a certain extent and
for a time disturbed by the subversion of their long-
established notions, would be distressed without any
need, and might be seriously unsettled. While, on
the other hand, a too protracted and obstinate resist-
ance to the innovation, on the part of the scriptural
expositors, would tend to identify, at least in the
minds of many, the authority of the Scripture with the
truth of the exposition; and therefore would bring dis-
credit upon the revealed word, when the established
interpretation was finally proved to be untenable.
A rule on this subject, propounded by some of the
most enlightened dignitaries of the Roman Catholic
church, on the occasion of the great Copernican con-
troversy begun by Galilco, seems well worthy of our
attention. The following was the opinion given by
Cardinal Bellarmine at the time:-'When a demon-
stration shall be found to establish the earth's motion,
it will be proper to interpret the sacred Scriptures
otherwise than they have hitherto been interpreted in
those passages where mention is made of the stability
of the earth and movement of the heavens.' This
appears to be a judicious and reasonable maxim for
such cases in general. So long as the supposed scien-
tific discovery is doubtful, the exposition of the mean-
ing of Scripture given by commentators of established
credit is not wantonly to be disturbed: but when a
scientific theory, irreconcileable with this ancient in-
RELATION OF TRADITION TO PALETIOLOGY. 307
terpretation, is clearly proved, we must give up the
interpretation, and seek some new mode of under-
standing the passage in question, by means of which it
may be consistent with what we know; for if it be not,
our conception of the things so described is no longer
consistent with itself.
It may be said that this rule is indefinite, for who
shall decide when a new theory is completely demon-
strated, and the old interpretation become untenable ?
But to this we may reply, that if the rule be assented
to, its application will not be very difficult. For when
men have admitted as a general rule, that the cur-
rent interpretations of scriptural expressions respecting
natural objects and events may possibly require, and
in some cases certainly will require, to be abandoned,
and new ones admitted, they will hardly allow them-
selves to contend for such interpretations as if they
were essential parts of revelation; and will look upon
the change of exposition, whether it come sooner or
later, without alarm or anger. And when men lend
themselves to the progress of truth in this spirit, it is
not of any material importance at what period a new
and satisfactory interpretation of the scriptural diffi-
culty is found; since a scientific exactness in our
apprehension of the meaning of such passages as are
now referred to is very far from being essential to our
full acceptance of revelation.
10. In what Spirit should the Change be accepted?
-Still these revolutions in scriptural interpretation
must always have in them something which distresses
and disturbs religious communities. And such uneasy
feelings will take a different shape, according as the
community acknowledges or rejects a paramount inter-
pretative authority in its religious leaders. In the
case in which the interpretation of the Church is
binding upon all its members, the more placid minds
rest in peace upon the ancient exposition, till the
spiritual authorities announce that the time for the
adoption of a new view has arrived; but in these cir-
cumstances, the more stirring and inquisitive minds,
which cannot refrain from the pursuit of new truths
X 2
308
PHILOSOPHY OF PALETIOLOGY.
2.
and exact conceptions, are led to opinions which, being
contrary to those of the Church, are held to be sinful.
On the other hand, if the religious constitution of the
community allow and encourage each man to study
and interpret for himself the Sacred Writings, we are
met by evils of another kind. In this case, although,
by the unforced influence of admired commentators,
there may prevail a general agreement in the usual
interpretation of difficult passages, yet as each reader
of the Scripture looks upon the sense which he has
adopted as being his own interpretation, he maintains
it, not with the tranquil acquiescence of one who has
deposited his judgment in the hands of his Church,
but with the keenness and strenuousness of self-love.
In such a state of things, though no judicial severities
can be employed against the innovators, there may
arise more angry controversies than in the other case.
It is impossible to overlook the lesson which here
offers itself, that it is in the highest degree unwise in
the friends of religion, whether individuals or commu-
nities, unnecessarily to embark their credit in exposi-
tions of Scripture on matters which appertain to natu-
ral Science. By delivering physical doctrines as the
teaching of revelation, religion may lose much, but
cannot gain anything. This maxim of practical wis-
dom has often been urged by Christian writers. Thus
St. Augustine says*: 'In obscure matters and things
far removed from our senses, if we read anything, even
in the divine Scripture, which may produce diverse
opinions without damaging the faith which we cherish,
let us not rush headlong by positive assertion to either
the one opinion or the other; lest, when a more
thorough discussion has shown the opinion which we
had adopted to be false, our faith may fall with it:
and we should be found contending, not for the doc-
trine of the sacred Scriptures, but for our own; endea-
vouring to make our doctrine to be that of the Scrip-
tures, instead of taking the doctrine of the Scriptures
to be ours.' And in nearly the same spirit, at the
4 Lib. i. de Genesi, cap. xviii.
RELATION OF TRADITION TO PALETIOLOGY. 309
time of the Copernican controversy, it was thought
proper to append to the work of Copernicus a postil,
to say that the work was written to account for the
phenomena, and that people must not run on blindly
and condemn either of the opposite opinions. Even
when the Inquisition, in 1616, thought itself compelled
to pronounce a decision upon this subject, the verdict
was delivered in very moderate language;—that ‘the
doctrine of the earth's motion appeared to be contrary
to Scripture:' and yet, moderate as this expression is,
it has been blamed by judicious members of the Roman
church as deciding a point such as religious authorities
ought not to pretend to decide; and has brought upon
that church no ordinary weight of general condemna-
tion. Kepler pointed out, in his lively manner, the
imprudence of employing the force of religious autho-
rities on such subjects: Acies dolabræ in ferrum illisa,
postea nec in lignum valet amplius. Capiat hoc cujus
interest. 'If you will try to chop iron, the axe be-
comes unable to cut even wood. I warn those whom
it concerns.'
II. In what Spirit should the Change be urged?—
But while we thus endeavour to show in what manner
the interpreters of Scripture may most safely and most
properly accept the discoveries of science, we must not
forget that there may be errours committed on the
other side also; and that men of science, in bringing
forward views which may for a time disturb the minds
of lovers of Scripture, should consider themselves as
bound by strict rules of candour, moderation, and
prudence. Intentionally to make their supposed dis-
coveries a means of discrediting, contradicting, or
slighting the sacred Scriptures, or the authority of
religion, is in them unpardonable. As men who make
the science of Truth the business of their lives, and are
persuaded of her genuine superiority, and certain of
her ultimate triumph, they are peculiarly bound to urge
her claims in a calm and temperate spirit; not forget-
ting that there are other kinds of truth besides that
which they peculiarly study. They may properly reject
authority in matters of science; but they are to leave
310
PHILOSOPHY OF PALETIOLOGY.
it its proper office in matters of religion. I may
here again quote Kepler's expressions: 'In Theology
we balance authorities, in Philosophy we weigh rea-
sons.
'Some
A holy man was Lactantius who denied that
the earth was round; a holy man was Augustine, who
granted the rotundity, but denied the antipodes; a
holy thing to me is the Inquisition, which allows the
smallness of the earth, but denies its motion; but more
holy to me is Truth; and hence I prove, from philoso-
phy, that the earth is round, and inhabited on every
side, of small size, and in motion among the stars,-
and this I do with no disrespect to the Doctors.' I the
more willingly quote such a passage from Kepler, be-
cause the entire ingenuousness and sincere piety of his
character does not allow us to suspect him in anything
of hypocrisy or latent irony. That similar professions
of respect may be made ironically, we have a noted
example in the celebrated Introduction to Galileo's
Dialogue on the Copernican System; probably the part
which was most offensive to the authorities.
years ago,' he begins, 'a wholesome edict was promul-
gated at Rome, which, in order to check the perilous
scandals of the present age, imposed silence upon the
Pythagorean opinion of the mobility of the earth.
There were not wanting,' he proceeds, 'persons who
rashly asserted that this decree was the result, not of
a judicious inquiry, but of passion ill-informed; and
complaints were heard that councillors, utterly unac-
quainted with astronomical observation, ought not to
be allowed, with their sudden prohibitions, to clip
the wings of speculative intellects. At the hearing of
rash lamentations like these, my zeal could not keep
silence.' And he then goes on to say, that he wishes,
in his Dialogue, to show that the subject had been
fully examined at Rome. Here the irony is quite trans-
parent, and the sarcasm glaringly obvious. I think we
may venture to say that this is not the temper in
which scientific questions should be treated; although
by some, perhaps, the prohibition of public discussion
may be considered as justifying any evasion which is
likely to pass unpunished.
RELATION OF TRADITION TO PALETIOLOGY. 31I
12.
Duty of Mutual Forbearance. We may add,
as a further reason for mutual forbearance in such
cases, that the true interests of both parties are the
same. The man of science is concerned, no less than
any other person, in the truth and import of the
divine dispensation; the religious man, no less than
the man of science, is, by the nature of his intellect,
incapable of believing two contradictory declarations.
Hence they have both alike a need for understanding
the Scripture in some way in which it shall be con-
sistent with their understanding of nature. It is for
their common advantage to conciliate, as Kepler says,
the finger and the tongue of God, his works and his
word. And they may find abundant reason to bear
with each other, even if they should adopt for this
purpose different interpretations, each finding one
satisfactory to himself; or if any one should decline
I
employing his thoughts on such subjects at·all.
have elsewhere" quoted a passage from Kepler which
appears to me written in a most suitable spirit: 'I be-
seech my reader that, not unmindful of the divine
goodness bestowed upon man, he do with me praise
and celebrate the wisdom of the Creator, which I open
to him from a more inward explication of the form
of the world, from a searching of causes, from a de-
tection of the errours of vision; and that thus not
only in the firmness and stability of the earth may we
perceive with gratitude the preservation of all living
things in nature as the gift of God: but also that in
its motion, so recondite, so admirable, we may acknow-
ledge the wisdom of the Creator. But whoever is too
dull to receive this science, or too weak to believe the
Copernican system without harm to his piety, him,
I
6
say, I advise that, leaving the school of astronomy,
and condemning, if so he please, any doctrines of the
philosophers, he follow his own path, and desist from
this wandering through the universe; and that, lift-
ing up his natural eyes, with which alone he can see,
5 Bridgewater Tr. p. 314.
• Com. Stell. Mart. Introd.
312
PHILOSOPHY OF PALETIOLOGY.
he pour himself out from his own heart in worship
of God the Creator, being certain that he gives no
less worship to God than the astronomer, to whom
God has given to see more clearly with his inward
eyes, and who, from what he has himself discovered,
both can and will glorify God.'
13. Case of Galileo.—I may perhaps venture here
to make a remark or two upon this subject with re-
ference to a charge brought against a certain portion
of the History of the Inductive Sciences. Complaint
has been made' that the character of the Roman
church, as shown in its behaviour towards Galileo, is
misrepresented in the account given of it in the His-
tory of Astronomy. It is asserted that Galileo pro-
voked the condemnation he incurred; first, by perti-
naciously demanding the assent of the ecclesiastical
authorities to his opinion of the consistency of the
Copernican doctrine with Scripture; and afterwards by
contumaciously, and, as we have seen, contumeliously
violating the silence which the Church had enjoined
upon him. It is further declared that the statement
which represents it as the habit of the Roman church
to dogmatize on points of natural science is unfounded;
as well as the opinion that in consequence of this
habit, new scientific truths were promulgated less
boldly in Italy than in other countries. I shall reply
very briefly on these subjects; for the decision of them
is by no means requisite in order to establish the doc-
trines to which I have been led in the present chapter,
nor, I hope, to satisfy my reader that my views have
been collected from an impartial consideration of scien-
tific history.
With regard to Galileo, I do not think it can be
denied that he obtruded his opinions upon the eccle-
siastical authorities in an unnecessary and imprudent
manner. He was of an ardent character, strongly
convinced himself, and urged on still more by the con-
viction which he produced among his disciples, and
* Dublin Review, No. ix. July, 1838, p. 72.
RELATION OF TRADITION TO PALETIOLOGY. 313
thus he became impatient for the triumph of truth.
This judgment of him has recently been delivered by
various independent authorities, and has undoubtedly
considerable foundation. As to the question whether
authority in matters of natural science were habitually
claimed by the authorities of the Church of Rome, I
have to allow that I cannot produce instances which
establish such a habit. We, who have been accustomed
to have daily before our eyes the Monition which the
Romish editors of Newton thought it necessary to
prefix-Cæterum latis a summo Pontifice contra tellu-
ris motum Decretis, nos obsequi profitemur—were not
likely to conjecture that this was a solitary instance of
the interposition of the Papal authority on such sub-
jects. But although it would be easy to find declara-
tions of heresy delivered by Romish Universities, and
writers of great authority, against tenets belonging to
the natural sciences, I am not aware that any other
case can be adduced in which the Church or the Pope
can be shown to have pronounced such a sentence.
I am well contented to acknowledge this; for I should
be far more gratified by finding myself compelled to
hold up the seventeenth century as a model for the
nineteenth in this respect, than by having to sow
enmity between the admirers of the past and the
present through any disparaging contrast.
8 Besides the Dublin Review, I may
quote the Edinburgh Review, which
I suppose will not be thought likely
to have a bias in favour of the ex-
ercise of ecclesiastical authority in
matters of science; though certainly
there is a puerility in the critic's
phraseology which does not add to
the weight of his judgment. 'Galileo
contrived to surround the truth with
every variety of obstruction. The
tide of knowledge, which had hither-
to advanced in peace, he crested with
angry breakers, and he involved in
its surf both his friends and his foes.'
-Ed. Rev. No. cxxiii. p. 126.
9 I may add that the most candid
of the adherents of the Church of
Rome condemn the assumption of
authority in matters of science, made,
in this one instance at least, by the
ecclesiastical tribunals. The author
of the Ages of Faith (book viii. p.
248), says, 'A Congregation, it is to be
lamented, declared the new system to
be opposed to Scripture, and there-
fore heretical.'
314
PHILOSOPHY OF PALETIOLOGY.
With respect to the attempt made in my History to
characterize the intellectual habits of Italy as produced
by her religious condition,-certainly it would ill be-
come any student of the history of science to speak
slightingly of that country, always the mother of sci-
ences, always ready to catch the dawn and hail the
rising of any new light of knowledge. But I think
our admiration of this activity and acuteness of mind
is by no means inconsistent with the opinion, that new
truths were promulgated more boldly beyond the Alps,
and that the subtilty of the Italian intellect loved to
insinuate what the rough German bluntly asserted.
Of the decent duplicity with which forbidden opinions
were handled, the reviewer himself gives us instances,
when he boasts of the liberality with which Copernican
professors were placed in important stations by the
ecclesiastical authorities, soon after the doctrine of the
motion of the earth had been declared by the same au-
thorities to be contrary to Scripture. And in the same
spirit is the process of demanding from Galileo a pub-
lic and official recantation of opinions which he had
repeatedly been told by his ecclesiastical superiors he
might hold as much as he pleased. I think it is easy
to believe that among persons so little careful to recon-
cile public profession with private conviction, official
decorum was all that was demanded. When Galileo
had made his renunciation of the earth's motion on his
knees, he rose and said, as we are told, E pur si muove
and yet it does move.' This is sometimes repre-
sented as the heroic soliloquy of a mind cherishing its
conviction of the truth, in spite of persecution; I
think we may more naturally conceive it uttered as a
playful epigram in the ear of a cardinal's secretary,
with a full knowledge that it would be immediately
repeated to his master 10
•
Besides the Ideas involved in the material sciences,
10 I have somewhat further dis-
cussed the case of Galileo in the
later editions of the History, book v
chap. iii. sect. 4.
RELATION OF TRADITION TO PALETIOLOGY. 315
of which we have already examined the principal ones,
there is one Idea or Conception which our Sciences do
not indeed include, but to which they not obscurely
point; and the importance of this Idea will make it
proper to speak of it, though this must be done very
briefly.
1
CHAPTER V.
OF THE CONCEPTION OF A FIRST CAUse.
I.
T the end of the last chapter but one, we were
led to this result, that we cannot, in any
of the Palætiological Sciences, ascend to a beginning
which is of the same nature as the existing cause of
events, and which depends upon causes that are still in
operation. Philosophers never have demonstrated, and
probably never will be able to demonstrate, what
was the original condition of the solar system, of the
earth, of the vegetable and animal worlds, of languages,
of arts. On all these subjects the course of investiga-
tion, followed backwards as far as our materials allow
us to pursue it, ends at last in an impenetrable gloom.
We strain our eyes in vain when we try, by our natural
faculties, to discern an origin.
2. Yet speculative men have been constantly em-
ployed in attempts to arrive at that which thus seems
to be placed out of their reach. The Origin of
Languages, the Origin of the present Distribution of
Plants and Animals, the Origin of the Earth, have
been common subjects of diligent and persevering
inquiry. Indeed inquiries respecting such subjects
have been, at least till lately, the usual form which
Palætiological researches have assumed. Cosmogony,
the Origin of the World, of which, in such speculations,
the earth was considered as a principal part, has been
a favourite study both of ancient and of modern
times: and most of the attempts at Geology previous
to the present period have been Cosmogonies or Geo-
gonies, rather than that more genuine science which
we have endeavoured to delineate. Again: Glossology,
though now an extensive body of solid knowledge, was
CONCEPTION OF A FIRST CAUSE.
317
mainly brought into being by inquiries concerning the
Original Language spoken by men; and the nature of
the first separation and diffusion of languages, the first
peopling of the earth by man and by animals, were
long sought after with ardent curiosity, although of
course with reference to the authority of the Scriptures,
as well as the evidence of natural phenomena. Indeed
the interest of such inquiries even yet is far from being
extinguished. The disposition to explore the past in
the hope of finding, by the light of natural reasoning
as well as by the aid of revelation, the origin of the
present course of things, appears to be unconquerable.
'What was the beginning?' is a question which the
human race cannot desist from perpetually asking.
And no failure in obtaining a satisfactory answer can
prevent inquisitive spirits from again and again repeat-
ing the inquiry, although the blank abyss into which
it is uttered does not even return an echo.
3. What, then, is the reason of an attempt so per-
tinacious yet so fruitless? By what motive are we im-
pelled thus constantly to seek what we can never find?
Why are the errour of our conjectures, the futility of
our reasonings, the precariousness of our interpreta-
tions, over and over again proved to us in vain? Why
is it impossible for us to acquiesce in our ignorance
and to relinquish the inquiry? Why cannot we con-
tent ourselves with examining those links of the chain
of causes which are nearest to us,-those in which the
connexion is intelligible and clear; instead of fixing
our attention upon those remote portions where we
can no longer estimate its coherence? In short, why
did not men from the first take for the subject of their
speculations the Course of Nature rather than the
Origin of Things?
To this we reply, that in doing what they have thus
done, in seeking what they have sought, men are im-
pelled by an intellectual necessity. They cannot con-
ceive a Series of connected occurrences without a Com-
mencement; they cannot help supposing a cause for
the Whole, as well as a cause for each part; they can-
not be satisfied with a succession of causes without
318
PHILOSOPHY OF PALÆTIOLOGY.
assuming a First Cause. Such an assumption is neces-
sarily impressed upon our minds by our contemplation
of a series of causes and effects; that there must be a
First Cause, is accepted by all intelligent reasoners as
an Axiom: and like other Axioms, its truth is neces-
sarily implied in the Idea which it involves.
4. The evidence of this axiom may be illustrated in
several ways. In the first place, the axiom is assumed
in the argument usually offered to prove the existence
of the Deity. Since, it is said, the world now exists,
and since nothing cannot produce something, some-
thing must have existed from eternity. This Some-
thing is the First Cause: it is God.
Now what I have to remark here is this:-the con-
clusiveness of this argument, as a proof of the existence
of one independent, immutable Deity, depends entirely
upon the assumption of the axiom above stated. The
World, a serious of causes and effects, exists: therefore
there must be, not only this series of causes and effects,
but also a First Cause. It will be easily seen, that
without the axiom, that in every series of causes and
effects there must be a First Cause, the reasoning is
altogether inconclusive.
5. Or to put the matter otherwise: The argument
for the existence of the Deity was stated thus: Some-
thing exists, therefore something must have existed
from eternity. 'Granted,' the opponent might say;
but this something which has existed from eternity,
why may it not be this very series of causes and effects
which is now going on, and which appears to contain
in itself no indication of beginning or end?'
thus, without the assumption of the necessity of a
First Cause, the force of the argument may be re-
sisted.
And
6. But, it may be asked, how do those who have
written to prove the existence of the Deity reply to
such an objection as the one just stated? It is natural
to suppose that, on a subject so interesting and so long
discussed, all the obvious arguments with their replies,
have been fully brought into view. What is the re-
sult in this case?
CONCEPTION OF A FIRST CAUSE.
319
The principal modes of replying to the above objec·
tion, that the series of causes and effects which now
exists, may have existed from eternity, appear to be
these.
In the first place, our minds cannot be satisfied with
a series of successive, dependent, causes and effects,
without something first and independent. We pass
from effect to cause, and from that to a higher cause,
in search of something on which the mind can rest;
but if we can do nothing but repeat this process, there
is no use in it. We move our limbs, but make no
advance. Our question is not answered, but evaded.
The mind cannot acquiesce in the destiny thus pre-
sented to it, of being referred from event to event,
from object to object, along an interminable vista of
causation and time. Now this mode of stating the
reply,—to say that the mind cannot thus be satisfied,
appears to be equivalent to saying that the mind is
conscious of a Principle, in virtue of which such a view
as this must be rejected;—the mind takes refuge in
the assumption of a First Cause, from an employment
inconsistent with its own nature.
4
7. Or again, we may avoid the objection, by put-
ting the argument for the existence of a Deity in this
form: The series of causes and effects which we call
the world, or the course of nature, may be considered as
a whole, and this whole must have a cause of its exist-
ence. The whole collection of objects and events may
be comprehended as a single effect, and of this effect
there must be a cause. This Cause of the Universe
must be superior to, and independent of the special
events, which, happening in time, make up the uni-
verse of which He is the cause. He must exist and
exercise causation, before these events can begin: He
must be the First Cause.
Although the argument is here somewhat modified
in form, the substance is the same as before. For the
assumption that we may consider the whole series of
causes and effects as a single effect, is equivalent to the
assumption that besides partial causes we must have a
First Cause. And thus the Idea of a First Cause, and
320
PHILOSOPHY OF PALÆTIOLOGY.
the axiom which asserts its necessity, are recognized in
the usual argumentation on this subject.
8. This Idea of a First Cause, and the principle
involved in the Idea, have been the subject of dis-
cussion in another manner. As we have already said,
we assume as an axiom that a First Cause must exist;
and we assert that God, the First Cause, exists eter-
nal and immutable, by the necessity which the axiom
implies. Hence God is said to exist necessarily ;-to
be a necessarily existing being. And when this neces-
sary existence of God had been spoken of, it soon began
to be contemplated as a sufficient reason, and as an ab-
solute demonstration of His existence; without any
need of referring to the world as an effect, in order to
arrive at God as the cause. And thus men conceived
that they had obtained a proof of the existence of the
Deity, à priori, from Ideas, as well as à posteriori,
from Effects.
9. Thus, Thomas Aquinas employs this reason-
ing to prove the eternity of God': 'Oportet ponere
aliquod primum necessarium quod est per se ipsum
necessarium; et hoc est Deus, cum sit prima causa
ut dictum est: igitur Deus æternus est, cum omne
necessarium per se sit æternum.' It is true that the
schoolmen never professed to be able to prove the
existence of the Deity à priori: but they made use
of this conception of necessary existence in a manner
which approached very near to such an attempt. Thus
Suarez' discusses the question, 'Utrum aliquo modo
possit à priori demonstrari Deum esse.' And resolves
the question in this manner: Ad hunc ergo modum
dicendum est: Demonstrato à posteriori Deum esse
ens necessarium et a se, ex hoc attributo posse à
priori demonstrari præter illud non posse esse aliud
ens necessarium et a se, et consequenter demonstrari
Deum esse.'
But in modern times attempts were made by Des-
cartes and Samuel Clarke, to prove the Divine exist-
1 Aquin. Cont. Gentil. lib. i. c. xiv. p. 21.
2 Metaphys. tom. ii. disp. xxix. sect. 3, p. 28.
CONCEPTION OF A FIRST CAUSE. 321
ence at once à priori, from the conception of necessary
existence; which, it was argued, could not subsist
without actual existence. This argumentation was
acutely and severely criticised by Dr. Waterland.
10. Without dwelling upon a subject, the discussion
of which does not enter into the design of the present
work, I may remark that the question whether an à
priori proof of the existence of a First Cause be possi-
ble, is a question concerning the nature of our Ideas,
and the evidence of the axioms which they involve,
of the same kind as many questions which we have
already had to discuss. Is our Conception or Idea
of a First Cause gathered from the effects we see
around us? It is plain that we must answer, here
as in other cases, that the Idea is not extracted from
the phenomena, but assumed in order that the pheno-
mena may become intelligible to the mind;-that the
Idea is a necessary one, inasmuch as it does not depend
upon observation for its evidence; but that it depends
upon observation for its development, since without
some observation, we cannot conceive the mind to be
cognizant of the relation of causation at all. In this
respect, however, the Idea of a First Cause is no less
necessary than the ideas of Space, or Time, or Cause in
general. And whether we call the reasoning derived
from such a necessity an argument à priori or à poste-
riori, in either case it possesses the genuine character
of demonstration, being founded upon axioms which
command universal assent.
II. I have, however, spoken of our Conception ra-
ther than of our Idea of a First Cause; for the notion
of a First Cause appears to be rather a modification of
the Fundamental Idea of Cause, which was formerly
discussed, than a separate and peculiar Idea. And the
Axiom, that there must be a First Cause, is recognised
by most persons as an application of the general Axiom
of Causation, that every effect must have a Cause; this
latter Axiom being applied to the World, considered in
its totality, as a single Effect. This distinction, how-
ever, between an Idea and a Conception, is of no
material consequence to our argument; provided we
VOL. II.
Y
322
PHILOSOPHY OF PALETIOLOGY.
allow the maxim, that there must be a First Cause, to
be necessarily and evidently true; whether it be thought
better to speak of it as an independent Axiom, or to
consider it as derived from the general Axiom of
Causation.
12. Thus we necessarily infer a First Cause, although
the Palætiological Sciences only point towards it, and
do not lead us to it. But I must observe further;
that in each of the series of events which form the sub-
ject of Palætiological research, the First Cause is the
same. Without here resting upon reasoning founded
upon our Conception of a First Cause, I may remark
that this identity is proved by the close connexion of all
the branches of natural science, and the way in which
the causes and the events of each are interwoven with
those which belong to the others. We must needs be-
lieve that the First Cause which produced the earth
and its atmosphere is also the Cause of the plants
which clothe its surface; that the First Cause of the
vegetable and of the animal world are the same; that
the First Cause which produced light produced also.
eyes; that the First Cause which produced air and
organs of articulation produced also language and the
faculties by which language is rendered possible: and
if those faculties, then also all man's other faculties;-
the powers by which, as we have said, he discerns
right and wrong, and recognises a providential as
well as a natural course of things. Nor can we think
otherwise than that the Being who gave these facul-
ties, bestowed them for some purpose;-bestowed
them for that purpose which alone is compatible with
their nature:-the purpose, namely, of guiding and
elevating man in his present career, and of preparing
him for another state of being to which they irresisti-
bly direct his hopes. And thus, although, as we have
said, no one of the Palætiological Sciences can be
traced continuously to an Origin, yet they not only
each point to an Origin, but all to the same Origin.
Their lines are broken indeed, as they run backwards
into the early periods of the world, but yet they all
appear to converge to the same invisible point. And
1
CONCEPTION OF A FIRST CAUSE.
323
this point, thus indicated by the natural course of
things, can be no other than that which is disclosed
to us as the starting-point of the providential course
of the world; for we are persuaded by such reasons
as have just been hinted, that the Creator of the
natural world can be no other than the Author
and Governor and Judge of the moral and spiritual
world.
43. Thus we are led, by our material Sciences, and
especially by the Palætiological class of them, to the
borders of a higher region, and to a point of view from
which we have a prospect of other provinces of know-
ledge; to contemplations in which other faculties of
man are concerned besides his intellectual, other in-
terests involved besides those of speculation. On these
it does not belong to our present plan to dwell: but
even such a brief glance as we have taken of the con-
nexion of material with moral speculations may not
be useless, since it may serve to show that the prin-
ciples of truth which we are now laboriously collect-
ing among the results of the physical sciences, may
possibly find some application in those parts of know-
ledge towards which men most naturally look with
deeper interest and more serious reverence.
We have been employed hitherto in examining the
materials of knowledge, Facts and Ideas;-Facts in
our former History, and Ideas in the present History.
We have dwelt at length on this latter element; inas-
much as the consideration of it is, on various accounts,
and especially at the present time, by far the most im-
portant, having hitherto been least distinctly attended
to as a special element of scientific knowledge.
There still remains an important task, with a view
to which we have undertaken this survey of the past
course of human thought and discovery:-namely, the
task of determining the processes by which these mate-
rials may actually be made to constitute knowledge.
324
PHILOSOPHY OF PALETIOLOGY.
We have surveyed the stones which lie before us, partly
built and partly ready for building: we have found
them exactly squared, and often curiously covered with
significant imagery and important inscriptions. We
have now to discover how they may best be fitted into
their places, and cemented together, so that rising stage
above stage, they may grow at last into that fair and
lofty temple of Truth, for which we cannot doubt that
they were intended by the Great Architect.
This task, the description of the processes by which
Scientific Truth is discovered and established, we shall,
as has already been said, entitle, in reference to pre-
vious attempts of the same kind, Novum Organum
Renovatum.
END OF VOL. II.
Cambridge: Printed at the University Press.
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