aV - \ / ,♦ ^' ^"'^^^^.c ,v r% ^.mw.- <^ ^. ^t"^ ■:> is ^ <.^ .10 '^ ^ O i> X ^ $^% ^ H ^^ V I ft 'i- *}■ Ci> •>,. 9 I V o c ^\ .^ s> ,0o. \ * r ^' ^^ fciv^%-" \ ^ Cv / . . s '^ <0 ^ ^ '\ O. ^/ -0- 'VL %<' .- ^ '> N ^/ \ \.'.^' ^^ A v< « V -^ /\ C^"^ ^>? .0 o - A^ ^ -^i *<> ^^ V d^ V' L^^ ^^. ,,#' -"^"^ .0^ ,\ V V <. •f Digitized by the Internet Archive in 2011 with funding from The Library of Congress http://www.archive.org/details/elementsoflogick03hedg b- "y-y-A^S^ ^l^'T^tt^'^ ^ ELEMENTS OF logick; OR A SUMMARY OF THE GENERAL PRINCIPLES AND DIFFERENT MODES OP REASONING. BY LEVI HEDGE, a. m. PROFESSOR OF LOGICK AND METAPHYSICK5, IN HARVARD COLLEGE. r TUIRB EDITION. BOSTON : PUBLISHED BY CUMMINGS AND HILLIAKD, Univ, Fress..,..Hilliard & Metcalf. 1821 DISTRICT OF MASSACHtrSETTS TO WIT s /district Cleric's Office, BE IT REMEMBERED, that on the twenty Dinth day of May, A. D. 1816, and in the fortieth year of the Independence of the United States of America, Levi Hed^e, Esq. of the said district has deposited in this office the title of a book, the ri^ht whereof he ciaims as author, in the words foi lowing-, vizu ** Elements of Logick ; or a summary of the general principles and different modes of reasoning. By Levi Hedge, A. M Professor of Logick and Metaphys- icks, in Harvard College." In conformity to the Act of the Congress of the United States, entitled, " An act lor the < ncouragement of learning, by securing th^' copies of maps, charts, and books, to theviuthors and proprietors of such copies, during the times there- in mentioned ;" and also to an act, entitled, " An act supplementary to an act, entitled. An act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies during the times therein mentioned ; and extending the oenefits thereof to the arts of designing, engraving and etching historical and other prints." * W. S. SHAW, Ckrk of the District of Massachusetts, , by symplifying its principles, and divesting it of its ancient trappings of modes and figures. Condillac has proved the importance of the method of induction, by pointing out the manner, in which nature teaches us to analyse the objects, which IV* PREFACE*:^ she presents to our observation. In ^' An Essay on the *' elements, principles, and different modes of reasoning,'* by Richard Kirwan, LL. D. all the subjects, which properly fall within the precincts of Logick, are amply discussed. But this work is too minute and prolix to he used as a text book in seminaries of education. Every person, who is much conversant with this department of knowledge, must have perceived the want of a treatise of Logick, more elementaiy., and better accommodated to the present improved state of thephilosophy of the mind, than any of those, which are now in use. The professed object of Logick is to furnish rules for the direction of the understanding in its various inqui- ries after knowledge. It should therefore teach the prin- ciples of every species of reasoning, which we have oc- casion to make use of, both in the pursuits of science, and in the ordinary transactions of life. Demonstrative reasoning can be employed only about general truths^ and such relations, as are in their nature immutable. It is of little use in regulating our judgments and con- clusions concerning events, which are irregular in their occurrence, and which depend on contingent circum- stances. To reason on subjects of this kind, it is ne- cessary to understand the nature of moral evidence, and the grounds of probability. It is by moral evidence alone, that we reason on historical facts, and the casual occurrences of life. It is also this evidence, which influ- ences our conclusions on the important and interesting subjects of government, morals, and religion. Under these impressions, the writer of this compend has pursued the following plan. After passing through the customary distinctions of terms and propositions, he has given a brief account of moral evidence, and pointed out the circumstances, which distinguish it from demonstrative. A concise view is then given of the dif- ferent forms of reasoning, with the principles, on which they respectively proceed. The books, which have been principally consulted in forming this summary, and in which the greatest part of the following principles may be found, are Watts' Logick, Lockers Essay on the Understanding, Reid's Essays on the Intellectual Powers, Stewart's Elements of the Philosophy of the Mind, Beattie's Essay on Truth, Tatham's Chart and Scale of Truth, Collard's Essentials of Logick, Kirwan's Logick, Campbell's Philosophy of Rhetorick, Gambier*s Introduction to Moral Evidence, Belsham's Compendium of Logick, and Scott's Elements of Intellectual Philosophy. Where passages have been borrowed entire, credit is given in the usual way. At the close of the several chapters may be found the names of those authors, from whom particular assistance has been derived. 1^ PREFACE TO THE THIRD EDITION. The present edition of the Elements of Logick is printed in a smaller type^ than either of the preceding^ in order that the copies may be afforded at a reduced price. The author has carefully revised the work^ and has enlarged it by the addition of a few pages, containing some general principles and rules, respecting controversy, and also a system of rules for the interpretation of written docu- ments. These have been collected with care from authors of high reputation, and, it is hop- ed, will not be thought an unsuitable appendage to a system of logick. In a few places, slight alterations have been made in the language and in the arrangement ; and some notes have been inserted at the end of the book, which were not in the preceding editions. Harvard College, JVov* 1821. CONTENTS. PART FIRST. A DESCRIPTION OF THE LEADING FACULTIES AND OPE« RATIONS OF THE MIND. Introduction. - . - - - CHAP. I. Perception and Consciousness. CHAP. II. Attention. - - - - - - CHAP. IIL Comparing. - - - - - CHAP. IV. Abstraction. - - CHAP. V. Association. - - . - - CHAP. VI. Analysis, - - - - - - PART SECOND. OF TERMS AND PROPOSHTONS. CHAP. 1. Logical distinctions of lerms. Page. 13 15 19 21 - 2S . £5 £8 SI X CONTENTS. CHAP. IL Definition and Division. - - - - 59 CHAP. III. General description of Propositions. *• - 44 CHAP, IV. Simple, Complex, and Modal Propositions. - 47 CHAP. V. Quality and Quantity of Propositions. - - 50 CHAP. VI, Opposition and Conversion of Propositions. - 55 CHAP. VII. Compound Propositions. - - - - 59 PART THIRD. OF JUDGMENT AND REASONING. CHAP. I. Intuitive Evidence. - - - - - 65 CHAP. [T. Difference between Moral and Demonstrative Rea- soning, ----.---fO CHAP. HI. Induction. - • - - • - . 75 CHAP. IV. Analogy ... - . . . 83 CHAP. V. Reasoning on Facts. - - ... 88 CHAP. VI. Calculation of Chances. - . - - 101 CONTENTS, XI CHAP. VIT. I General description of Demonstrative Reasoning, 108 CHAP. VKL Distinctions of Reasoning. . . - • us CHAR IX. General description of Syllogistick Reasoning. 116 CHAP. X. Of Regular {Syllogisms. - . » - ^ 120 CHAP. XL Enthymemes. ------ 130 CHAP. xn. Conditional and Disjuntive Syllogisms. - - 134 CHAP. xni. Compound Syllogisms. ----- 1S;7 CHAP. XIV. Sophisms. - - - - « - - 144 CHAP. XV. Disposition or Method. - - - ^ - 149 Rules of Controversy. - - - - 157 Rules of Interpretation. - • . . 162 Concluding Remarks. - • - ^ - 167 Notes and Illustrations. - - - - in ii^ ELEMENTS OF LOGICK, PART FIRST. A DESCRIPTION OF THE LEADING FACULTIES AND OPE llATIONS OF THE MIND, INTRODUCTION. 1. The purpose of Logick is to direct the intellectual powers in the investigation of triithp and in the communication of it to others. Its foundation is laid in the philosophy of the hu- man mind^ inasmuch as it explains many of its powers and operations^ and traces the pro- gress of knowledge from the first and most sim- ple perceptions of outward objects^ to those remoter truths and discoveries^ which result from the operations of reasoning, 2. Logick instructs us in the right use of termsj and distinguishes their various kinds. It teaches the nature and varieties of propo- sitions ; explains their properties^ modifica- 2 14 INTRODUCTION. tions^ and essential parts. It analyzes the structure of arguments^ and shows how their truth may be discovered^ or their fallacy de- tected. Lastly it describes those methods of classification and arrangement^ which will best enable us to retain and apply the knowledge^ which we have acquired. 3. Though the understanding would be inca- pable of any high degree of improvement^ with- out the aid of rules and principles^ yet these are insufficient without practice and experi- ence. The powers of the mind^ like those of the body^ must be strengthened by use. The art of reasoning skilfully can be acquired only by a long and careful exercise of the reasoning faculty^ on different subjects and in various ways. The rules of logick afford assistance to this faculty^ not less important than that^ which our animal strength derives from the aid of mechanical powers and en- gines. They guide its operations^ and supply it with suitable instruments for overcoming the difficulties^ by which it would be impeded in its search after truth. 4. In the following compend^ the subjects of logick are distributed into three parts. The PERCEPTION AND CONSCIOUSNESS. 15 first contains a brief description of the lead- ing faculties and operations of the mind. The second;, of the several kinds of terms and prop- ositions. The third comprises an explana- tion of moral and demonstrative evidence ; of the diiferent modes of reasoning ; of soph- isms ; and of method^ or disposition. CHAPTER FIRST. PEllCEPTION AND CONSCIOUSNESS. 5. Perception is the first faculty^ which ap- pears in the human mind. By this we gain all our knowledge of the powers and qualities of the material objects about us. The instruments of perception are the five corporeal senses^ see- ing^ feelings hearings tasting^, and smelling. All the intercourse;, which the mind has with the material world^ is carried on by these organs. Of the manner^ in which this inter- course proceeds^ we have no knowledge. From experience we learn^ that a sensible alteration takes place in the mind^ w^henever any outward object is so situated^ as to affect either of the senses. The change^ produced in the mind by the impression of the object on the organ of sense^ is denominated sensation. The word 16 PEBCEPTION AND CONSCIOUSNESS. perception refers to the knowledge^ that we gain by sensation^ of some quality in the ob- ject ;^ which knowledge may be retained by the mind after the object is removed^ and it is then usually called an idea or notion. The external object^ or quality perceived^ is de- nominated the object of perception^ or the archetype of the idea. 6. If either of the senses be wholly wanting^ the mind must be forever destitute of all that class of ideas;, which it is the office of that sense to furnish. If either be possessed but imper- fectly^, the ideas., received from it^ are liable to be faint and indistinct. But the usual ef- fects of dull organs may be in a great measure obviated;, by an increased effort of attention^ while the objects are present ; as is manifest in the case of persons^ who have had their hearing in some degree impaired. It is from habitual inattention to our sensa- tions^ more than from dulness in the organs * " The sensations, which are excited in the mind by ex- '* tenisil objects, and the perceptions of material qualities, which ^' follow those sensations, are to be distinguished from each " other only by long habits of patient reflection.'^ Stexvart^ Elem, vol. i. ch. v part Sd^ sect. 1st, PERCEPTION AND CONSCIOUSNESS. 17 of sense^ that so few of the objects^ which strike our senses, leave anv durable traces in the mind ; and that those notions^ which do re- main^ are so often obscure and indistinct. As the preceptions of sense are the elements of all our knowledge^ we should cultivate the habit of carefully noticing the things^ which we see^ feel^ and the like ; in order that the notions^ which we form of them^ may be clear and distinct. 7. Consciousness^ or reflection^ is that notice^ which the mind takes of its own operations^ and modes of existence."^ By this we are made acquainted with the successive chan- ges, which take place in the state of our minds. Consciousness is similar to percep- tion, though the qualities of body, which are the objects of the latter, bear no resem- blance to the thoughts and operations of the mind, which are the objects of the for- mer. The mind, at least whilst we are awake^ is constantly employed in some mode of think- ing, or in some exertion of its powers ; and all the operations, passions, and affections of the mind, are necessarily subject to its own * See note A, at the end of the book. 18 PERCEPTION AND CONSCIOUSNESS. observation. Thus^ by consciousness we learn what is expressed by the words compare^ rea- son^ doubt^ assent;, joy^ in the same manner^ as by perception we gain a knowledge of sweety green^, soft^ cold. 8. Both perception and consciousness^ consid- ered apart from any acts of attention^ accompa- nying them^ are involuntary states of mind. We are often active in bringing external objects within our view^ and in varying their position^ for the purpose of careful observation ; so^ by a voluntary effort, we excite operations^ and cause changes in the mind ; but the knowl- edge^ that we gain in each case^ of the subjects thus presented^ is without any act of the will. We cannot avoid hearing many sounds^ and seeing the objects^ which are placed before our eyes. We are constrained to smell odours^ taste our food;, and feel bodies^ when in contact with our own. It is the same with respect to the operations and states of the mind. We are unable to compare^, reason^ abstract ; to feel pain^ pleasure^ disgust^ or the likC; without being conscious of those states. V* ATTENTION. 19 CHAPTER SECOND. ATTENTION. 9. Attentio?t expi^esses the immediate direc- tion of the mind to a subject. The distinctness of our notions^, the correctness of our judg- ments^ and the improvement of all our intel- lectual powers^ depend^ in a great degree^ on the habitual exercise of this p^ct. Its surpris- ing influence^ in improving the perceptive pow- ers^ is manifest in persons^ who have been led^ by their peculiar callings^ or by necessity, to place uncommon reliance on a particular sense. Thus sailors^ v^ho are accustomed to look at distant objects^ acquire the power of seeing and distinguishing things^ which^ by reason of their distance^ are invisible to common eyes. Musicians become capable of discerning the minutest difference in sounds. Cooks and epi- cures acquire an uncommon sensibility in tast- ing and smelling ; and blind persons improve the sense of feeling to such a degree^ as to make it^ in some measure^ supply the want of sight. These effects are produced solely by an increased and habitual attention^ which 20 ATTENTION, enables those persons to notice impressions^, which are so slight and languid^ as wholly to escape the observation of others. 10. Attention is considered"^ a voluntary act of the vfiind. but it is not at all times equally subject to our command^ and in young children is wholly involuntary. Extraordinary occur- rences^ which awaken curiosity^ and things^ which interest us in a high degree^ by exciting some violent passion or emotion^ often draw the attention so strongly, that we are unable for a time to transfer it to any other subject. So intensely are we sometimes engaged, that we lose our account of time, and take no notice of the objects, which strike the senses. 11. Attention is so essential to memory, that without some degree of it no thought could ever be recalled ; and the reason why we com- mit things to memory more easily at one time, than another, is, that we command our atten- tion more perfectly. It is equally necessary in every operation of comparing, judging, and reasoning. Dr. Reid has remarked, *• that, if '' there be any thing that can be called genius • Stewart, Elements of the philosophy of the mind, vol. i. ch. % Reid, Essays on the active powers. Essay II. ch. 3. COMPAKING, 21 ^^in matters of mere judgment and reasonings it seems to consist chiefly in being able to give that attention to the subject^ which keeps it steady in the mind^ till we can survey it accurately on all sides. There is a talent of imagination^ which bounds from earth to heaven^ and from heaven to earthy in a mo- ment. This may be favourable to wit and imagery; but the powers of judging and rea- soning depend chiefly on keeping the mind to a clear and steady view of the subject.^^^ CHAPTER THIUD. COMPARING. 12. When the mind contemplates two things in reference to each other^ it performs the op- eration of comparing. Thus^ when we say iron is harder than lead^ and lead is heavier than iron^ we compare these two substances with respect to the degrees^ in which they possess the qualities of weight and hardness. From this operation we derive all our notions of relation ; as father^ cousin^ largeness^ small- ness, superiority^ subjection^ and the like. * Essays on the active powers, Essay 11. cb. 3. 22 COMPAHING. We make comparisons with the greatest ease^ and frequently without being conscious of them. It is only by this operation^ that v/e are enabled to recognise the objects^ which we have be- fore known^ or to give ^o any quality or object an appropriate name ; for the application of the name requires not only the sensation^ pro- duced by a present object^ but the comparison of that sensation with one formerly felt.* 13. This operation is performed by children in their earliest efforts at speech. It is by successively comparing the sounds^ they utter^ with those^ made by others^ that they learn to pronounce the words of their native tongue. That propensity to imitation^, v/hich is always conspicuous in the sports of children^ is hap- pily calculated to improve this effort of the mind. The same may be asserted of many of those studies^ which usually occupy the years of childhood^ and particularly of the study of foreign languages. Translations from one language to another require a constant and careful comparison of the corresponding words of different languages ; an exercise doubly • Stewart, Elements, vol. i. ch. 3. ABSTRACTION. 23 important to children^ as it serves to improve their discerning faculties^ and at the same time leads them to ascertain the exact import of words. The correctness of every process of judgment and reasoning depends^ immediately or ultimately;, on the accuracy of our compar- isons. CHAPTER FOURTH. ABSTRACTION. 14. Abstraction literally implies the separa- ting of one thing from another ; but^ as a men- tal operation;, it denotes only a partial consid- eration of any thing. It is the act of coiisid- ering one or more of the properties or circum- stances of an object J apart from the rest. Thus we may consider the length of a bridge^ with- out regarding its breadth or construction. We may speak of fluidity in water^ hardness in marblc; or sweetness in sugar^ without noticing the other properties of those substances. As the quality^ thus mentally separated from those existing with it^ may be found in numer- ous subjects^ the name applied to it becomes a general term. So whiteness stands for the 24 ABSTRACTION. color of snow^ milk^ chalky paper^ and many other things. 15. This power^ which the mind has^ of separating the qualities combined in the ob- jects^ which fall under our observation^ and of tracing the same quality in a multitude of ob- jects, is the foundation of all classification ; and gives rise to the general words of language. But, notwithstanding the necessity of abstrac- tion in every act of classification, it may be performed on individuals, without referring them to any class. This has occasioned some^ to suppose, that the formation of classes requir- ed a distinct operation, which they called gen- eralisation. Dr. Reid says, ^^we cannot gen- " eralise without some degree of abstraction, but I apprehend we may abstract, without generalising. For what hinders me from at- tending to the whiteness of the paper before me, without applying that color to any other object? The whiteness of this individual object is an abstract conception ; but not a general one, while applied to one individual only. These two operations, however, are * Reld, Intellectual Powers, Essay V. ch. 3. Collard, Log- kk, part I. ch. 2. ASSOCIATIOK. 25 '^ subservient to each other ; for the more at- " tributes we observe and distinguish in any '' one individual^ the more agreements we shall ^•discover between it and other individuals/' CHAPTER FIFTH. ASSOCIATION. 16. By the association of ideas is understood that connexion among the thoughts^ affections^ and operations of the mind^ by which one has a tendency to introduce another. That one idea is often suggested to the mind by another^ and that sensible objects revive past trains of thought^ are facts familiar to all. Words re- call the objects^ to which they have been ap« plied ; and the objects as readily suggest their names. A long train of associated thoughts is sometimes introduced by a single circum- stance. The view of the spot^ where we pas- sed the first years of life^ after a long absence^ will recall many interesting events of child- hood. The first notes of a familiar tune^ being sounded^ will cause the remaining notes to pass through the mind in regular order. 17. No principle of our nature is produc- tive of more important effects, than this^ which 3 26 ASSOCIATION. establishes a connexion between our ideas;, feel- ings^ and mental operations. It is the source of numerous errors and prejudices. It is the foundation of all our local attachments ; and of most of our prepossessions in behalf of the government and other institutions of our coun- try. It is to the principle of association^ that we are to attribute our predilections for the modes of dress^ pronunciation^ and behav- iour of those;, whom we esteem and respect. The principles of association have been dif- ferently stated ; but the following are those^ in which there is the most general agreement. 18. Firsts resemblance or analogy is an ex- tensive principle of association. We are often reminded of one person^ by the countenance^ voice^ or gestures of another. One natural scene suggests another; and one event or one anecdote frequently brings another to our re- membrance^ by the similarity we observe be- tween them. 19. Secondly^ opposition or contrast is anoth- er principle of association^ but of less exten- sive influence^ than the preceding. The pains of hunger and thirst suggest the pleasures of eating and drinking. Cold reminds us of ASSOCIATION. 27 heat ; darkness^ of light ; and parsimony^ of prodigality. So^ among contending parties^ extravagance on one side usually drives the other to the opposite extreme. 20. Thirdly^ another^ and with the bulk of mankind the most extensive;, ground of asso- ciation^ is contiguity^ or nearness of time and place. The recollection of an event^ in which we were interested^ brings to our thoughts many circumstances connected with it^ as the place we were in^, when it happened^ or when we were informed of it ; the persons^ who were with us ; and the peculiar state of our feelings at the time. The objects we meet on a road, that wx have formerly travelled^ successively remind us of the subjects^ about which we were employed^ when we passed them before. 21. A fourth principle of association re- sults from the relations of cause and effect^ pre* raises and consequences. The sight of a sur- gical instrument^ or an engine of torture^ ex- cites a strong sense of the pain^ it is calculat- ed to occasion ; and the sight of a wound re- minds us of the instrument^ by which it was made. When we see a fellow being in distress, we are solicitous to find out the cause ; and 28 ANALYSIS^ when we have afflictive tidings to communicate^ we anticipate the grief, which will be excited. 22. As one idea may be associated with sev- eral others^ each leading to a different series, it is obvious, that the same circumstance may suggest different trains of thought to different persons ; and to the same person at different times. The association of ideas is concerned in every act of memory and recollection. No thought, after it has once passed from the mind, could ever be recalled, were it not for the tendency of one idea to introduce another.^ CHAPTER SIXTH. ANALYSIS 23. Analysis deserves a place among the operations, by which the elements of knowledge are acquired. Without this, our perceptive powers would give us only confused and im* perfect notions of the objects around us. To analyze is nothing more^ than to distinguish suc- cessively the several parts of any compound subject. Nature dictates this process. We * Hume, Essays, vol. ii. sect. 3. Stewart, Elem. vol. i. ch. 5. Beattie, dissertations, mor. and crit. vol. i, ch, 2, sect, ii Scott, Elem. Intel. Phil. ch. v« sect. L ANALYSIS. 29 commence it at the earliest period of improve- ment; and practise it in all our efforts to obtain information. The objects^ which nature pre- sents to usj, consist of assemblages of different qualities^ some more and others less easily dis- tinguished. Children early become acquaint- ed with the distinguishing properties of the things^ daily offered to their senses ; and in a few years find out the characteristick marks of numerous classes of things^ and learn the use of language. 24. Things^ which have no immediate refer- ence to material objects^ such as thoughts^ af- fections; and mental operations^ are analyzed in the same manner^ as objects of sense. The words abstract and reason denote processes of thought; each of which may be readily distin- guished into separate partS; and these parts in- to others more remote. The same may be said of moral qualities^ as justice^ prudence^ benevolence^ and the like. In these^ as in sensible objects^ there are certain parts^ which are instantly noticed^ and others^ which are discovered by attentive observation. The analysis begins in both cases with the leading 3"^ 30 ANALYSIS, qualities^ and becomes more perfect^ as new qualities are discovered. 25. We employ analysis in interpreting symbolical language^ and ambiguous proposi- tions. Analysis enables us to investigate caus- es by their effects ; and to find out the means necessary to attain an end proposed^ by having the end first in view. It is by this instrument^ that the chemist and botanist retrace the pro- cesses of nature^ and ascertain the qualities of mineral and vegetable substances. Analysis will be further considered undet*^ the head of inductive reasoning.* ♦ CondiUac, Logick, part 1. Watts, Logick, part iv. ch, I. Stewart, Elem. vol. ii. cb. 4. PAET SECOND. OF TERMS AND PROPOSITIONS* CHAPTER FIRST, LOGICAL DISTINCTIONS OF TERMS. 26. Words possess no natural aptness to de- note the particular things^ to which they are applied^ rather than others ; but acquire this aptness wholly by convention. Had the con- nexion between the name and the thing been established by nature^ there would have been but one language in the world. But we find different words employed in different countries^ and with equal advantage^ to signify the same thing. Thus white^ albus^ and blanc^ denote the same color. The principal distinctions of terms in logick are the following. 27. First, terms are either simple or com- plex. A simple term is a single word ; as man, horse, tree. A complex term consists of two or more words^ representing some object or as- sociation^ formed to be the subject or predicate of a proposition ;* as human fortitude, a swift * See ch. 3. 33 DISTINCTIONS OF TERMS. horse^ an amiable deportment. A wordy which denotes several individuals of the same sort^ is called a collective term ; as army^ forest^ drove* 28. Secondly^ terms are distinguished into absolute and relative. Ari absolute term is one^ which represents an object or quality ^ without intimating its relation to any other thing ; as man; river^ mountain^ roundness^ strength. A relative term denotes an object so far only^ as it is connected with some other object. Thus^ father implies a man primarily^ as he is con- sidered the cause of existence to another indi- vidual; denominated; in reference to him^ son. These two terms^ intimating each other^ by a reciprocal reference^ are called correla- tive. So patron and client^ husband and wife^ guardian and ward; are correlative terms. There are other relative terms; as who; which; it; that; and the likc; which barely re- call certain other words; before mentioned; hence the words they refer to are denominat- ed antecedents. 29. Thirdly; terms are distinguished into univocaly equivocal^ and synonymous. Univocal terms are suchy as have invariably the same signification annexed to them. Thus individ- TERMS, 33 uality, geniis^ electricity^ are univocal terms ; for they always signify the same things. Equivocal words are suchy as are employed in different senses. Of this sort is the word head, which may signify a part of a nail, of an an- imal, or of a discourse. So the words post and shore are equivocal, for they are used in various senses. That some words should be used in different senses is unavoidable, on account of the scanti- ness of language, which does not afford a dis- tinct name for every idea. Notwithstanding this, we sometimes find two or more words ap- plied to the same thing ; as wave and billow ; dwelling and habitation. These are called synonymous terms. 30. A fourth distinction of terms is into abstract and concrete. An abstract term is one^ which signijies some quality or attribute ^ with- out referring to any subject j in which it may be found ; as roundness, hardness, equality, firm- ness. Concrete terms denote both the attributes and the subjects^ to which they belong. Some- times they express the subjects directly j and the attributes indirectly ; and sometimes the reverse. Thus philosopher, statesman, me- 34 TERMS. ehanick^ are concrete terms^ which directly denote persons^ and indirectly^ the attributes^ for which they are distinguished. But wise^ valiant^ swift^ hard^ are concretes^ immediately signifying certain attributes^ and indirectly intimating the persons or things^ to which they belong. 31. Fifthly^ terms are either singular or uni- versal. A singular term is the proper name of some individual person^ place^ or thing ; as Alexander^ London^ Danube^ Etna. Proper names are given only to those things^ which we have frequent occasion to mention^ as individuals. The design of proper names is to represent these^ apart from the classes^ to which they belong. Any term^ that does this office^, is a proper name ; and loses not its character as such by being applied^ as it fre- quently is;, to several individuals of the same kind;, as Peter^ John^, William. 32. Universal terms^ otherwise denominated common or appellative^ are names^ indiscrimi- nately applicable to many individual beings^ whether natural or artificial^ by reason of certain properties^ which they possess in com- TERMS. 35 in on. Thus man, city, river, mountain, are universal terms, because they agree to all men^ cities, rivers, and mountains. 33. Universal terms make the greatest part of the words of every language. Their sig- nification is designedly imperfect ; comprising only the most common and obvious properties of things. They are abridgments of lan- guage, happily contrived to facilitate and expe- dite the intercourse of society. Every produc- tion of nature and art, and every property of mind and body, is an individual. Each has some properties peculiar to itself ; and others, which it possesses in common with many other beings. By discarding the peculiar properties, and retaining under distinct names those^ which are common, we reduce to a limited number of classes the innumerable objects, which fall under our observation. This dis- tribution of things into classes forms what lo- gicians call the genera and species of things. 34. Species denotes a sort or class^ including only individuals ; and genus^ a class^ including under it two or more species. A species is formed by applying a name to that property, or collection of properties, in which many in- 36 TERMS. dividuals are found to agree. Thus man is a species ; for the name is applicable to an in- definite number of individual beings, on ac- count of their agreeing in the essential prop- erties of an erect figure, and the faculties of speech and reason. So horse, deer, eagle^ tree, are species. Genus implies the property or properties, which diff*erent species possess in common. Thus the property of walking on four feet is the foundation of the genus quad- ruped ; which applies to horse, lion, dog, ele- phant, and many other species. So bird is a genus, of which eagle, lark, swan, and sparrow, are species. 35. In the distribution of things into genera and species, regard is had to the comprehension and extension of general terms. By the com- prehension of a term^ is meant the aggregate of all the known properties of that things or class of things^ to which it is applied. Thus gold j includes in its comprehension a material sub- stance, a yellow color, superior weight, duc- tility, fusibility, and every other known pro- perty of that body. The extension of a term regards the number of individual subjects^ to which it may be applied. So the term gold in- 1 Vis if TERMS. 37 eludes ill its extension every separate parcel of that metal. Man includes in its extension ev-^ ery individual of the human race. 36. Classes are multiplied^ as the conven- ience of language is found to require ; nature having affixed no limits to the number^ that may be formed. As the number of classes in- creases^ the names^ which express them^ be- come more complicate in their signification^ and less extensive in their application to in- dividuals. Hence it is received as a maxim in logick^ that^ as the comprehension of a general term is enlarged^ its extension must be dimin- ished ; and the contrary. The comprehension of any species is obviously greater^ than that of the genus^ to which it is subordinate ; for the species includes all the attributes of the genus^ and others in addition. Thus^ in the following subordinate terms^ swallow^ bird, animal^ all the attributes of bird are found in swallow, and all those of animal; in bird ; but;, in each remove^ a part of the first collection of attributes is discarded. The case is different with respect to their extension ; that of animal is much greater than that of bird^ and that of bird greater than that of swallow. 4 0*^ 38 TERMS* 37* The ranks^ which lie above any class^ or which embrace a wider extension^ are cal- led^ in reference to it^ superior; and that^ which terminates the series, is called most gen- eraly or the highest genus. Descending from this^ each rank is called inferior ; and the low- est class^ which includes only individuals^ is called the lowest species. All the intermediate ranks^ between the highest genus and the lowest species^ are termed subaltern ; each being indifferently either a genus or a spe- cies^ according as it is considered in the as- cending or descending series. Thus bird is a genus^ when referred to eagle^ raven^ spar- row \ but a species^ when referred to the more general term animal. 38. The genus next above any species is cal- led the proximate genus^ and any genus above that^ a remote genus of that species. Thus quadruped is the proximate^ and animal a re- mote genus of horse. The property or collec- tion of properties^, by which any species is dis- tinguished from every other species of the same genus^ is the specifick difference. So juice is the proximate genus of wine ; but the cir- cumstance of being pressed from grapes is the f -■4 DEFINITIOJ^. 39 specifick diiference^ which distinguishes wine from cider and perry^ which are also juices.* CHAPTER SECOND. DEFINITION A^^D DIVISION. 39. Definitions are usually distinguished in- to two kinds ; one nominal^ or of the name ; the other realy or of the thing. A definition of the name is merely a specification of the ob- ject^ to which a name is applied. A definition of the thing is properly an analysis of a things or an enumeration of its principal attributes. 40. Words^ which stand for indivisible ob- jects^ admit only of nominal definitions. These are sometimes sufficiently explained by intelli- gible synonymous words ; thus being denotes existence ; identity implies sameness. Those, which stand for simple qualities of body, may be defined by referring to the subjects, in which those qualities reside ; and those, that denote mental states, by describing the occasions, on which they are produced. Thus yellow is the * Locke, Essay on the imderstanding", B. Ill, ch. 3. Tleidj, Essays, vol. ii. Essay 5, cb. 1. Belsbam, Logick, part i. sect, 4 and 5. Kirwan, Logick, part u cli. 2, sect. 2. 40 DEFINITION, color of gold or saffron. Suprise is the pas- sion^ or state of mind^ produced by the percep- tion of some new or uncommon object. 41. A real definition leads us to a knowledge of the nature of a things by enumerating its most essential modes and properties. Thus a circle is a figure^ whose circumference is^ in every part^ equally distant from the centre. Injustice is an intentional violation of anoth- er's rights. Real definition includes the nom- inal ; for an explanation of the nature of any thing necessarily fixes the signification of the name^ by which it is called. Natural substan- ces, and all compound beings, whether real or imaginary, are susceptible of real definitions. 42. Logicians divide a definition into two parts, Vvhich are called genus and difference. If the thing to be defined be in any degree general, that is, expressed by a generick term, the definition will be made up of the proxi- mate genus and the specifick difference. Thus bird is an animal, which has wings, feathers, and a hard, glossy bill. Animal is the prox- imate genus, denoting what bird has in com- mon with horse, deer, elephant ; the other terms denote the specifick difference ; for they | DEFINITION. 41 point out the properties^ which distinguish bird from every other species of animals. So square is a figure, which has four equal sides, and four right angles. Figure is the proxi- mate genus ; the other terms make the specif- ick difference. 43. If the thing to be difined be an individ- ual, having a proper name, the definition will consist of the species and an enumeration of so many properties, as will distinguish that indi- vidual from all others of that species. Thus Mercury is the planet nearest the sun. Plan- et is the lowest species ; nearest the sun is the circumstance, which sufficiently marks a difference between Mercuy and the other plan- ets. 44. There are many woi^ds in every language, which cannot be defined, because they have no uniform signification affixed to them. The, this, that, which, such, every, good, bad, de- sirable, and the like, are nearly insignificant sounds, till they are applied to particular things, from which they borrow a sort of local or tem- porary meaning ; and they often signify dif- ferent things, when applied to different sub- jects. Good, applied to a soldier, means cour» 4^ 43 DEFINITION* age ; to a Christian^ piety ; to a physician^ skill ; to a horse^ stength ; to a knife^ sharp- ness. 45. Words of this description^ which have no uniform signification afiixed to them^ are wholly employed in the definition of other terms. The definitive particles have no other iise^ than to restrain the latitude of general terms. For example^ the man^ this horse., that tree;, such an object. Here the names man^ horsc;, tree^ and object^ which represent whole classes of things^ are restrained by the words the^ this^ that^ and such^ to certain individu- als;, with which we are supposed to be already acquainted. Again^ a wide river^ a severe winter^ a de- lightfid prospect. The terms river^ winter^ and prospect^ are general ; wide^ severe^ and delightful^ denote specifick differences. Where- ever the latitude of a general word is restrain- ed by a definitive^ or a quality is attributed to a subject^ we may recognise the two essential parts of a definition^ namely^ genus and differ- ence. 46. Division is the explication of any whole by the enumeration of its component parts. DEFINITION. 43 Thus a tree is divided into trunks roots^ and branches ; animal^ into beast;, bird^ fish^ and insect. The term^ division^ is applicable to the resolution of a treatise or discourse into its several heads or branches ; also^ to the con- sideration of an equivocal word in reference to its different significations. The members of a division should exhaust the subject divided ; and they should be so oppos- ed^ that one will not be contained in another* The parts^ into which any thing is first divid- ed;, should be the largest and most general. The resolution of one of these parts into oth- ers^ more minute^ is called subdivision. So a year is first divided into months. Month is then subdivided into weeks ; week^ into days^ and so on. Needless subdivisions should be avoided^ as they burden the memory^ and in- troduce confusion .* CHAPTER THIRD. GENERAL DESCRIPTION OF PROPOSITIONS. 47. A proposition is a verbal representation of some perception^ acty or affection of the mincL * Locke, Essay, B. III. Watts, Logick, part I. Kirvvan^ Lo^ick, part I. 44 PROPOSITIONS. The constituent parts of a proposition are the subject^ the predicate^ and the copula. The two first are called terms^ because they are the extremes of the proposition ; and they may consist of a single word each^ or of a collection of words^ representing some person^ things or attribute. 48. The subject of a proposition is that^ con- cerning which something is either asserted^ dc" nied^ commanded^ or inquired. The predicate is that J which is asserted^ denied ^ or the like^ concerning the subject. The copula is thaty by xvhich the other txvo parts are connected. Body is divisible. Man is not omniscient. Be ye filled. Is C^sar dead ? Body^ man, ye^ and Csesar^ are the subjects of these four propositions ; divisible^, omniscient^ filled;, and dead, are the predicates ; is, is not, and be, the copulas. In the first example, the agreement between the subject and predicate is asserted ; in the second, it is denied ; in the third, it is ordered ; in the fourth, it is in- quired for. ■| PROPOSITIONS, 45 49. One part of a proposition is often con- tained in another. In the following examples^ the copula is contained in the predicate. I think. The sun rises. These imply^ I am thinking. The sun is rising. So the copula sometimes includes the whole^ or a part of the predicate ; as Troy was ; that is^ Troy was existent. The copula is always some inflection of the verb to be^ either ex- pressed or understood. A single word may contain a complete prop- osition. Thus scribo implies ego sum sari- bens^ I am writing. So rejoice^ attend^ imply be thou rejoicing ; be thou attentive. 50. The subject of the proposition usually stands first^ and the predicate last ; but this oi^der is sometimes inverted^ as in the following example. In China are many ingenious artists* That is^ Many ingenious artists are [existent] in China, 46 PROPOSITIONS. The words^ which constitute the two terms^ are sometimes so blended together^ that the whole^ or a part;, of one is placed between parts of the other. In the following example^ the whole subject intervenes between parts of the predicate. " But too often different is rational conjecture from melancholy fact." Burke. In imperative and interrogative propositions^ the copula is usually placed first. As^ Be thou faithful. Is the controversy settled ? 51* An identical proposition is oncj whose subject and predicate are composed of the same word or words^ and express precisely the same idea. Sometimes the terms are the same^ and the ideas different. Thus^ home is home. This proposition is not identical^ for home^ as sub- ject^ means only a place of residence ; but as predicate^ it denotes that it is an agreeable res- idence. Sometimes the terms are different^, but express the same idea. Thus^ three times three are nine ; twelve is the fifth part of sixty. Here the terms are reciprocal^, and may be substituted for each other ; but the propositions are not strictly identical. PROPOSITIONS, 47 CHAPTER FOURTH. SIMPLE, COMPLEX, AND MODAL PROPOSTIONS. 52. A simple proposition is one^ whose sub- ject and predicate are composed of simple terms. See No. 27. As, Time is precious. Virtue will be rewarded. A complex proposition has one or both of its terms complex. They are formed in different ways. A proposition is sometimes rendered complex, by having for its subject or predicate some other proposition, or words equivalent ; thus, That one man should be punished for the crimes of another is unjust. The words, which precede is^ and which form the subject of this example, obviously contain an entire proposition. 53. Frequently the subject of a proposition is first represented by the pronoun zY, and af- terwards distinctly expressed ; as in the fol- lowing expression ; " It is impossible to guess at the term, to which our forbearance would have extended,"* • Burke, Regicide Peace. 48 PROPOSITIONS. The words^ constituting the real subject^ are here represented by the word zV^ which be- ing discarded; and the subject stated first^ the proposition will read thus^ To guess at the term, to which our forbearance would have extended, is impossible. 54. Another manner of rendering a propo- sition complex is by introducing the pronoun who; which; or that; for the purpose of ex- plaining the subject or predicate, ThuS; Cyrus, who founded the Persian empire, was the son of Cambyses. The words; introduced by the relative; form a complete proposition; which is called the in- cident ; and the whole proposition; including this; is called, in reference to it; primary ^ or principal. As the design of the incident prop- osition is purely to explain the subject or predicate of the primary; it can be considered only as a part of the term; in v/hich it is plac- ed. 55. Lastly; any proposition is complex; whose subject or predicate is defined; by an- nexing to it a word of limitation; or restriction. AS; PflOPOSITIONS^ 49 Upright men are respected. The mind is a simple substance. The subject of the first example is defined b;^ -the word upright ; and the predicate of the second^ by the word simple. These words res- train the latitude of the general terms^ men and substance^ to which they are joined. They are equivalent to incidental propositions^, and may be readily resolved into them. Thus;, Men, who are upright, are respected. The mind is a substance, that is simple. 56. A modal proposition is ofie^ whose copula is qualijied by some word orwords^ representing the manner of the agreement or discrepancy be- txveen the subject and predicate. The modali- ty of propositions is frequently expressed by the auxiliary verbs^ may^ can^ must^ oughty and the like^ which imply possibility^ necessity^ ov contingency. Thus^ • Men of influence can do much good- Subordination must be maintained. The thing asserted^ in each of these proposi- tions^ is not the simple and absolute agreement of the subject with the predicate^, but barelf' 5 OO PROPOSITIONS. the nature of that agreement ; namely^ that it is possible or necessary.^ CHAPTER FIFTH. qUALITY AND qUANTITY OF PllOPOSITIONS. 57. Propositions are further distinguished into affirmative and negative ; which has been called a distinction with respect to quality. In affirmative propositions y the predicate and sub- ject are asserted to agree ; as^ Clovis was tlie founder of the French monarchy. In negative propositions^ the predicate is de- clared to be incompatible with the subject* This is commonly done by placing the nega- tive particle not immediately after the copula. Thus^ The world is not eternal. 58. Sometimes the negative particle is plac- ed so far from the copula^ that it appears to have no immediate connexion with it ; but rath- er to belong to some other part of the prop- osition. JVot all the troops united were able to defend the for- ti^ss, *Watts, Logick, part II. ch. 2» Kirwan, Logick, part I, ch. 2. PROPOSITIONS. 51 Here the negative word is placed before the subject ; but still its influence falls wholly on the copula^ and makes the proposition signify the opposite of what it would without it. This will be evident by stating the proposition thus^ All the troops united wei;e not able to defend the for- tress. 59. By the quantity of a proposition is meant its consideration in respect to the extent of its subject ; and according as the subject is used in the whole or a part of its extension^ propo- sitions are denominated universal ^v "particular. A universal proposition is one^ whose subject is a general term^ used in the whole of its exten- sion. The signs of universality are all^ each, every ^ noy neither^ and the like. Thus^ Ml free agents are accountable. Every sin is a violation of the Divine law. These are universal propositions ; because each subject includes an extensive class^ to each individual of which the predicate is de- clared applicable. 60. When the sign of universality is omit- ted; or the indefinite article is placed before 5^ PROPOSITIONS. the general subject^ the proposition is ealled indefinite. Thiis^ Planets are continually changing their places. A just sovereign regards the welfare of his subjects. These subjects are taken in their greatest ex- tent; for if there were any planet^ that did not change its place^ or any just sovereign^ who neglected the welfare of his subjects^ the propositions would not be true. 61. A particulav proposition is one^ whose subject is a general tervfij but is taken only in a part of its extension. The signs of particu- larity are sovfie^ many^ most^ several^ fi'^^ aud the like. vSome animals are amphibious. Many buildings were destroyed. The words^ some and many^ restrain the sub- jects^ animals and buildings^ and intimate^ that a part only of the individual beings^ which they include^ will admit the predicates^ amphibious and destroyed. 62. A proposition^ whose subject is the prop- er name of some individual person or things is denominated singular. As^ PROPOSITIONS. 53 Alfred founded the University of Oxford. Stagira was the birthplace of Aristotle, A definitive pronoun^ placed before the sub- ject of a proposition^, renders it singular. As^ That general was defeated. The subject of a singular proposition^ as it represents only an individual^ is necessarily taken in its whole extension ; for v^hich reason singular propositions are classed with univer- sals. Every proposition therefore is either universal or particular. 63. Besides this quantity in the subject^ there is another quantity in the predicate o^ a proposition ; for this;, as well as the subject^ is taken either in the whole^ or only in a part of its extension. The quantity of the subject and that of the proposition are the same ; for in every universal proposition^ the subject is universal ; and in every particular proposition^ the subject is particular. But the quantity of the predicate depends on the quality of the proposition. [See No. 57,] I?i all affirmative propositions the predicate is particular ; and in all negative propositions it is universal. 5^ 54 PROPOSITIONS. 64. The predicate of an affirmative propo- sitioii; separately considered^ is commonly a rnqre general term^ than the subject. It is usually a genus^ of which the subject is a spe- cies. But^ when united to the subject^ no greater extension is attributed to it^ than is just sufficient to enable it to embrace the sub- ject. It is taken in the whole of its compre- hension^ but^ in a part only of its extension. [See No. 35.] For example^ Every dog is an animal. Here it is barely asserted^ that the predicate^ animal^ does extend so far^ as to include every individual of the subject^ dog ; but it is neither asserted nor denied;, that it is susceptible of a greater extension. Now though the term^ animal^ separately considered^ is applicable to millions of beings besides dogs^ still in this place it has no more extension^ than is express- ly given it by the words of the proposition. The predicate of every affirmative proposition being in this way restrained by its subject^ universality can never be attributed to it. 65. But in negative propositions the pre- dicate is taken in the whole of its extension '; OPPOSITION AND CONVERSION. 55 and excludes from itself every individual with- in the range of the subject* Thus^ No animal is a tree. This proposition implies^ that the things^ in- cluded under tree^ are so dissimilar to those^ included under animal^ that no individual can be found^ to which the two terms will apply. CHAPTER SIXTH. OPPOSITION AND CONVERSION OF PROPOSITIONS. 66. Opposition in propositions implies a disa- greement in respect of quality. Two proposi- tions^ which have the same subject and the same predicate^ are said to be opposite^ when one absolutely denies^ in whole or in part^ what the other affirms. There are three ways^ in which propositions of this sort may be op- posed. First; a universal affirmative may be opposed to a particular negative. These are called contradictory. As^ Every defensive war is just. Some defensive wars are not just. Secondly^ a universal affirmative proposition may oppose a universal negative. These are iCalled contrary. As^ 56 OPPOSITION AND CONVERSION. Every disease is contagious. No disease is contagions. Thirdly^ a particular affirmative may be op- posed to a particular negative. These are call- ed sub contrary. As^ Some amusements are innocent. Some amusements are not innocent. Two contradictory propositions can never be either both true^, or both false^ at the same time. Contraries may be both false^ but they cannot be both true ; and subcontraries may be both true^ but they cannot be both false^ at the same time. 67. The conversion of a ^proposition is the transposition of its terms^ so that the subject shall take the place of the predicate^ and the predicate the place of the subject^ with the preservation of truth. When the subject and predicate simply change places^ without causing any alteration in the quantity of the propositions^ it is called a simple co?2version. But ifj in the new arrange- ment^ a term of particularity is introduced^ to restrain the subject of the derivative propo- sition within the same extension^ which it had^ as predicate of the original^ this is called a particular conversion : by the schoolmen it was OPPOSITION AND CONVERSION. 5j denominated conversio per accidens. Univet'^ sal affirmative propositions are usually conver- tible only in the latter mode ; but universal negatives and particular affirmatives are con- vertible in the former. 68. The converse of a universal affirmative proposition must^ generally speaking^^ be a particular affirmative. It is necessary that both the terms be taken in exactly the same extension^ in both arrangements ; and since by the rule^ stated in No. 63^ the predicate of the original proposition must be particular^ this same term must be particular in the converse^ where it is made the subject; which will there-^ fore render the j)roposition particular. Thus^ Orig, Prop. All swallows are birds. Converse. Some birds are sw^allows. 69. The converse of a universal negative proposition is a universal negative. The sub- ject and predicate being of equal extent^ mu- tually exclude each other; and as these terms * This is always the case, except in those propositions, whose predicate is a complete definition of the subject. In such propositions the subject and predicate are reciprocal ternvs. As four times five are twenty: and twenty are four times fiv^. Wine is the juice of the grape ; and the juice of the grape is wine. 58 OPPOSITION AND CONVEUSION. are both universal in the first arrangement^ [See No. 65.] they must be so in the second. Thus^ Orig. Prop, No deer is an elephant. Converse. No elephant is a deer. 70. Particular affirmative propositions are convertible only into the same. In these the terms are both particular ; [See No. 61^ 63.] and they can never become otherwise by a new arrangement. Thus^ Orig. Prop, Some birds lie dormant during the winter. Converse, Some beings, that lie dormant during the winter, are birds. 71. A particular negative proposition is in- convertible in any mode. Its subject is par- ticular^ and by conversion this subject would be made the predicate of a negative proposi- tion^ and must therefore be universal^ accord- ing to No. 65 ; a whole deduced from a part^ which is impossible. For example ; from this proposition^ Some birds are not swallows. We cannot affirm this^ No swallows are birds. This would be to deduce a whole from a part; COMPOUND PROPOSITIONS. 59 since swallow is denied of a part only of the extension of bird^ in the first proposition ; and of the whole of it^ in the last.^ 72. There is a third species of conversion^ in which a negative particle is inserted both in the subject and predicate of the derivative proposition^ unless previously included in the original. This is denominated conversion by contraposition. Thus^ Ovig. Prop, Every bird is an animal. Converse. That, which is not an animal, is not a bird. These negatives destroy each other^ and the proposition is considered as aJBirmative.f CHAPTER SEVENTH. COMPOUND PROPOSITIONS. 73. A compound proposition is one^ which has two or 7nore subjects^ or predicates^ or both; and may be resolvedinto two or rnore propositions* * In a universal affirmative proposition, the subject only is universal, and the predicate particular ; in a universal negative, the subject and predicate are both universal ; in a particular affirmative, the subject jiud predicate are botli particular ; and in a particular negative, the subject only is particular, and the predicate universal. t Watts, Logick^part II. ch. 2- Kirwan, Logick, part I. ch.6. 60 eOMPOtJND PROPOSITIONS. As, Spring, summer, autumn, and winter, are seasons of the year. Alfred was prudent, valiant, just, and benevolent. As the four subjects of the first example are separately applicable to the predicate^ seasons of the yeaVy and the four predicates of the last^ separately applicable to the subject^ Alfredy each may be resolved into four propositions^• Thus^ Spring is a season of the year. Summer is a season of the year, &c. 74. Every compound proposition may be reduced to as many single ones^ as it contains subjects, to which the whole predicate will ap- ply, and predicates, to which the whole subject will apply ; or as there are parts in each^ which are separately applicable to each other. Beasts, birds* and insects, have life, sense, and motion. This example contains three subjects and three predicates, and may be reduced to nine dis- tinct propositions. 75. Two or more words are sonietimes so coupled together in the subject or predicate, as to give the proposition the appearance of COMPOUND PROPOSITIONS. 61 being compound^ when it is single. Thus^ Joy and sorrow are opposite qualities. Ye cannot serve God and mammon. These are complex propositions^ but they are not compound ; for neither of them can be re- solved into two propositions. The two parts^ which make up respectively the subject of the one and the predicate of the other^ must be taken conjointly. 76. Compound propositions may be distin- guished from those^ that are barely complex^ by the following circumstances. First^ in a compound proposition^, the parts^ which con- stitute the subject or predicate^ are independ- ent of each other^ and may be taken separate- ly^ as well as conjointly ; which is not the case in complex propositions. In the latter^ either certain words are joined together^ which rep- resent integral parts of some whole^, that is to be the subject or predicate^ as three and seven are equal to ten ; or one part of the proposi- tion is repeated^ directly or implicitly^ by some relative word^ as ity that^ who^ which ; or last- ly the real subject or predicate is defined by an explanfitory word. In either of these cases^ 6 62 COMPOUND PROPOSITIONS. the words^ which render the proposition com- plex^ must be regarded^ as real parts of the term; in which they occur. 77. Secondly^ wherever a complex proposi- tion involves a simple one^ there will be the distinction of primary and incidental ; and the incidental proposition may be false^ while the primary is true. But^ in compound proposi- tions; there exists no distinction of primary and incidental; each part being independent of the rest ; and the compound proposition must be false; when either of the propositions^ it in- volves; is false; though the others be true. 78. Compound propositions are in most books of logick distributed into various sortS; denominated copulative^ disjunctive^ conditional^ causal^ relative^ and discretive ; which denom- inations are taken from the particle; employed in the composition of their subject or predicate. The examples; already giveii; belong to the first class. A disjuntive proposition asserts^ that a sub- ject agi^ees tvit/i one of two or more named pre d'- icatesj or a predicate with one of ttvo or more subjects enumerated*^ but does not specify which* COMPOUND PROPOSITIONS, 63 Thiis^ Either the sun or the moon will be eclipsed, on Christ- mas da J. The weather will, at that time, be either clear or cloudy, 79. A discretive proposition consists of txvo parts^ xvhich are contrasted by reason of some apparent opposition or inconsistency ^ intimated by the particles biitj though^ notwithstanding. and the like. As^ Hannibal, though unfortunate, was a great general. A man may deceive his neighbour, but not his God. 80. The other distinctions of this class are incorrect. What are usually termed condi- tional^ causal^ and relative propositions^ are nothing more; than different modes of connect- ing two entire propositions together. It is es- sential to the individuality of a proposition^ that it have but one copula. However com- pounded or complicated the subject or predi- cate may be^ they must be connected by a sin- gle affirmation or negation. This rule is vio- lated in every instance of what are called coii- ditional; causal^ and relative propositions. The following have been given^ as examples of these kinds, 64 COMPOUND PROPOSITIONS. If the sun be fixed, the earth must move. Rehoboam was unhappy, because he followed evil counsel. As is the Father, so is the Son. The first is given as an example of a condition- al^ the second^ of a causal^ and the third^ of a relative proposition. But neither of them can^ with any propriety, be considered as a com- pound proposition. Each example consists of two entire propositions, possessing distinct sub- jects, copulas, and predicates ; and so put to- gether, as to constitute a complete act of ra- tiocination.^ * Collard, Logick, part III. cb. 2. Kirwan, Logick, part L ch. 4. Watts, Logick, part II. ch. 2. PART THIRD. OF JUDGMENT AND REASONING. CHAPTER FIRST. INTUITIVE EVIDENCE. 81. Judgment is an act of the mindy uniti?tg or separating two objects of thought according as they are perceived to agree or disagree,. The relation between these objects is sometimes discovered by barely contemplating them^ with- out reference to any thing else ; and sometimes^ by comparing them wdth other objects^ to which they have a known relation. The former is simple comparison ; the latter is an act of rea- soning. The determination of the mind in both cases is denominated judgment. Every act of judgment is grounded on some sort of evi- dence. That^ which determines the mind in simple comparison^ is called intuitive evidence ; and that; which is employed in reasoning; de* ductive. 6^ 66 INTUITIVE EVIDENCE* The principal kinds of intuitive evidence^ or sources of intuitive belief, are the evidence of sense^ of consciousness^ of memory^ and of ax- iomsy or general pririciples. 82. The first source of intuitive belief is the testimony of the external senses^ hearings seeing^ touching^ smelling^ and tasting. These organs come to their usual degree of maturity in in- fancy, and are employed with equal confidence by all descriptions of people. Men have in every country, and in every period of the world, been governed by their testimony, even in their most important concerns. We can no more question the existence of the bodies, which we see and handle, than we can our own existence, or the truth of the most obvious maxim, that can be proposed to our thoughts. On the evidence of the senses is grounded all our knowledge of the nature, powers, and qual- ities of the material objects around us. All truths relative to physical science or to the events of history, and all those rules of pru- dence, which relate to the preservation and health of our bodies, must ultimately be resol- ved into this principle, that things are, as our senses represent them. INTUITIVE EVIDENCE. 67 83. Consciousness is another source of intui- tive evidence. Its office is to inform us of the present existence of our various passions, af- fections, and mental operations. The whole science of the human mind is built on this evi- dence ; and no branch of knowledge stands on a surer foundation ; for no evidence is superi- or to this, where it is completely ascertained. But it is sometimes difficult to define precisely the subjects of our consciousness. Those, who have not been accustomed to attend to their in- tellectual operations, are liable to err in ap- plying this evidence. I think, compare, reason, doubt ; I feel pain, or pleasure ; I remember past events. These are facts, of which I am conscious ; and of which I am unable to ques- tion the reality. The power of consciousness is exercised but imperfectly, till the mind ad- vances towards maturity. Some^ have sup- posed it to be wholly dormant during the years of^childhood. It is however exercised, in a greater or less degree, by people of all clas- ses ; and the subjects, about which it is em- ployed, can be no other, than the mental states of a being, which each one calls himself. * Scott, Intellectual Philosophy. 68 INTUITIVE EVIDENCE* 84. As the evidence of sense furnishes us with the knowledge of things present in the material world^ and the evidence of conscious- ness informs us of whatever is passing in our own minds ; so the evidence of memory gives us immediate knowledge of things past^ wheth- er of a material or intellectual kind. This evidence has ever commanded the belief of mankind as effectually, as that of sense. Past facts and occurrences^ of which we have a clear remembrance^ are regarded as certain. This is implied by men in all their efforts to gather knowledge and improvement from their past experience. It is on this principle^ that caus- es^ w^hich involve the lives and fortunes of men^ are decided by the testimony of witnesses^ in courts of justice. Propositions^ formerly prov- ed^ may be relied on as present knowledge^ though the reasons^ which first gained our as- sent to them, be now forgotten^ provided we remember^ that we once carefully investigated them^ and were then certain of their truth. Such propositions must often be introduced or referred to^ in demonstrations ; and should doubts be entertained respecting their truth^ INTUITIVE EVIDENCE. 69 they must weaken our confidence in the con- clusions^ to which they are subservient. Un- less therefore the evidence of memory be ad- mitted as a ground of certain knowledge^ the foundation of demonstrative reasoning w^ould be destroyed. 85. Another species of intuitive evidence is that; which accompanies mathematical axioms and all those abstract truths^ which carry their own evidence with them^ and are readily as- sented tO; as soon as they are contemplated. ThuS; the whole is greater than a part. Things c equal to the same are equal to one another. Every effect must have a cause. These prop- ositions force our assent by irresistible evi- dence^ as soon as we understand the terms^ by which they are expressed. They cannot be proved; because no principles more evident can be assumed^ from which their truth could be deduced. In all demonstrative reasonings constant use is made of these abstract and self- evident propositions.* * Beattie, Essay on truth, part I. ch. 2. Stewart, Elem. vol. ii. cb. 1. Campbell, Phil. Rhet. vol. i. ch. 5. Scott, Elera. In- tel. Phil, ch 8, sect. 3. 70 DEDUCTIVE EVIDENCE. CHAPTER SECOND. DIFFERENCE BETWEEN MORAL AND DEMONSTRATIVE REASONING. 86. Reasoning is a process^ by which un- known truths are inferred from those ^ xvhich are already known or admitted. The evidence^ employed in reasoning^, is deductive^ and is dis- tinguished into two kinds^ which are^ moral and demonstrative* Moral evidence is that species of proof which is employed on subjects^ directly or indirectly connected with moral con- duct. It is not however confined to such sub- jects ; but is extended to all those facts and events^ concerning which we do not obtain the evidence of sense^ intuition^ or demonstration ; and to all the general truths^ which are deduc- ed from observation and experience.* De- monstrative evidence is that^ which is derived froin the invariable properties and relations^ expressed by general terms. On this distinc- tion of deductive evidence is founded the most general division of reasoning-, which is into V2oral or probable^ and demonstrative. The * Gambler, Moral Evidence, ch. 1. DEDUCTIVE EVIDENCE. 71 principal diiferences in these modes of reason- ing are the following. 87. First, they differ in regard to their sub- jects. Demonstration is employed about ab- stract and independent truths, or those rela- tions, which are considered as necessary, and whose subjects may be exactly measured and defined. The properties of number and quan- tity are of this sort. They have no respect to time or place ; depend on no cause ; and are subject to no change. But the subjects of mo- ral reasoning are matters of fact, which are in their nature contingent, and the variable con- nexions, which subsist among things in actual existence. Thus, that mercury may be con- gealed by cold, that lead is fusible, that Han- nibal led an army over the Alps, that Lisbon was once destroyed by an earthquake, and the like, are truths within the province of moral reason- ing. 88. Secondly. In a demonstration, it is not necessary to examine more than one side of the question ; for if any proposition be demonstrat- ed to be true, whatever can be offered, as proofs on the opposite side, must be mere falla- 73 DEDUCTIVE EVIDENCE. cy. But in cases of moral reasonings there are frequently arguments of weight on both sides ; and therefore^ in order to judge cor- rectly^ we must consider each side of the ques- tion; and give our assent to that; on which there appears the greatest weight of evidence. Thus; having demonstrated the equality of the three angles of a triangle to two right ones; there is no need of inquiring what may be urg- ed against the demonstration. But the case is different in questions of a moral kind; as whether falsehood may be practised towards an assassin ; or whether an oath; extorted by violence; be obligatory. In such questions; the mind is often perplexed; and the judgment held in suspence by the conflict of opposite rea- sons< 89. Thirdly. Propositions; contrary to those established by moral evidence; are merely false / but those; which are contrary to demon- strated propositions; are not only falsC; but likewise absurd. ThuS; the assertion; that Carthage was never taken by the Romans; though falsC; is not absurd ; for there was a timc; when it was true. But the assertion. DEDUCTIVE EVIDENCE. 73 that the opposite angles^ formed by two straight lines crossing each other^ are not equal; is not only false, but also absurd. 90. Fourthly. In demonstration there are no degrees ; the conclusion resulting necessarily from the definitions and principles, which have been assumed, as the basis of the reasoning. But in moral reasoning there is often contrariety of evidence, and the degree of assurance, w^e feel in the conclusion, must depend on the de- gree, in which the evidence on one side exceeds that on the other. 91. Fifthly. In every process of demonstra- tive reasoning, the proofs are framed into one coherent series, each part of w^hich must have an intuitive agreement with that, which goes before, and with that, which follows it. The longest geometrical demonstration is but one uniform chain, the links of which, taken sepa- rately, are not regarded, as so many argu- ments ; and consequently, w^hen thus taken, they prove nothing. But taken together, and in their proper order, they form one argument, which is perfectly conclusive. In a process of moral reasoning, on the contrary, tliere is usu- ally a combination of many separate arguments, 74 BEDUCTIVE EVIDENCE, in no degree dependent on each other. Each possesses some weighty and bestows on the con- clusion a certain degree of probability ; of all which, accumulated^ the credibility of the fact is compounded. Thus^ the proof^ that the Ro« mans once possessed Great Britain^ is made up of a variety of independent arguments ; as im- memorial tradition ; the testimony of histori- ans 5 the ruins of Roman buildings^ camps^ and walls ; Roman coins^ inscriptions^ and the like. These are independent arguments 5 but they all conspire to establish the fact. 92. Sixthly. It may be further noticed^ that the obstacles^ which occur in the practice of these two modes of reasonings are of different kinds. Those^ which impede our progress in demonstration^ arise from the large number of intermediate steps, and the difficulty of finding suitable media of proof. In moral reasonings the processes are usually shorty and the chief obstacles^ by which we are retarded^ arise from the want of exact definitions to our words ; the difficulty of keeping steadily in view the vari- ous circumstances^ on which our judgment should be formed ; and from the prejudices arising from early impressions and associations. DEDUCTIVE EVIDENCE. 75 93. It should be remarked here^ that the epithet^ probable ^ as applied by logicians to the evidence of moral reasonings has a techni- cal meanings altogether different from its usual signification. In common discourse^ it is ap- plied to evidences which does not command a full assent ; but in logical discussions^ it has a more comprehensive meanings not only includ- ing every subordinate degree of moral evidence^ but also the highest. In this latter sense^ it is not to be considered as implying any deficiency of proofs but as contradistinguishing one spe- cies of proof from another ; — not as opposed to what is certaius but to what may be demonstrat- ed after the manner of mathematicians ; — not as denoting the degree of evidences but its jia- tiire. It is the more important to keep in mind this distinction between the popular and tech- nical meaning of the terms probable^ as the neg- lect or misapprehension of it has given origin to a distrust of moral reasonings as inferior in evidence to mathematical demonstration ; and induced many authors to seek for a mode of proof altogether unattainable in moral inc^ui- 76 INDUCTION. ries 5 and which^ if it could be attained^ would not be less liable to the cavils of scepticks.^ CHAPTER THIRD. INDUCTION. 94. The first kind of moral reasoning is that^ by which we infer general truths from partic- ular facts^ that have fallen under our observa- tion. This has been called the method of in- duction. It is founded on the belief^ that the course of nature is governed by uniform laws^ and that things will happen in future^ as we have observed them to happen in time past. We can have no proof of a permanent connexion between any events^ or between any two qual- ities either of body or mind. The only reason for supposing such a connexion in any instance is^ that we have invariably found certain things to have been conjoined in fact ; and this expe- rience^ in many cases^ produces a conviction equal to that of demonstration. 95. When a property has been found in * Ried, Intellectual powers, Essay VII. ch, 3» Campbell, Phil. Rhet. B. I. cb. 5. sect. 2 Gambler, Mor. Evid. ch. 1. Stew- art, Elem. Phil, of Mind, voL i, latrod. part II, sect. 2, voL ii. ch, 2. sect. 4? INDUCTION. 77 many subjects of a similar kind^ and no con- tradictory instance has been discovered;, though diligently sought^ we have an irresistible per- suasiou;, that the same property belongs to all the individuals of that class. Thus^, having applied a magnet to several masses of iron^ and found uniformly a strong attraction to take place^ we feel no doubt^ that it belongs to the nature of iron to be thus affected by that body ; and^ though our experience reaches only to a small part of the masses of iron in existence^ we assert with confidence^ that all iron is sus- ceptible of magnetical attraction. So^ having often noticed^ that by the application of heat to a certain degree^ water is made to boil^ and that^ in the absence of heat to a certain degree^ it becomes congealed ; and having ascertained these changes to be uniform^ so far as they have been observed by ourselves and others^ we readily ascribe them to the nature of water^ and conclude^ that in every country water will boil or freeze; on being exposed to those op- posite degrees of temperature. 96. In this way^ by observations and experi- ments on individuals of a similar kind^ noticing with exactness their agreement^ or the circum- 7^ 78 INDUCTION. stances^ in which they difFer^ we obtain gener- al truths relating to the properties and laws of material objects. By the same inductive pro- cess we investigate the laws^ which govern the phenomena of mind. Thus^ from experience it has been ascertained^ that^ when two ideas have been often presented to the mind in im- mediate succession^ they acquire a tendency mutually to suggest each other ; so that, when either of them occurs to our thoughts, the oth- er readily follows it. We learn also from ex- perience, that the durability of past impressions on the mind depends greatly on the attention, witli which they were at first received. From the uniformity of these facts we are taught, that contiguity in time or place is a principle of association ; and that attention is necessary to memory. 97. As we deduce the common properties of a single class of beings from observations on individuals of that class, so, by comparing in- dividuals of different classes, we discover im- portant resemblances between one species and another, and are enabled to obtain more exten- sive conclusions. Thus, having seen the milk of several animals of different species, and INDUCTION. 79 found it uniformly to be white^ we conclude^* that the milk of all animals is so. In like man- ner^ having witnessed the effect of fire on sev- eral pieces of gold^ iron^ lead^ and so forth, we affirm, that all metals are fusible. In this way, beginning with individuals, we ascend to species ; and thence proceed from less general to more general conclusions, till we arrive at those abstract propositions, which are called axioms or general truths. 98. This method of induction is recommend- ed by Lord Bacon, as the first and most im- portant instrument of reason, in its search af- ter truth. We employ it not only in the inves- tigation of general truths, relating to things in actual existence ; but in gaining those practical rules and maxims, by which the common busi- ness of life is carried on. 99. The use of induction, in learning the signification of words, is thus happily explained by Mr. Stewart. '^ A familiar illustration of '^ this process presents itself in the expedient, '' which a reader naturally employs for deci- ^^phering the meaning of an unknown word, in " a foreign language, when he happens not to " have a dictionary at hand. The first sen- 80 INDUCTIOISr* ^' tence^ where the word occurs^ aifords^ it is " probable^ sufficient foundation for a vague ^^ conjecture concerning the notion^ annexed " to it by the author ; some idea or other being " necessarily substituted in its place, in order " to make the passage at all intelligible. The " next sentence^ where it is involved^ renders ^' this conjecture a little more definite ; a third " sentence contracts the field of doubt within '' still narrower limits ; till at length a more ^^ extensive induction fixes completely the sig- " nification we are in quest of. There cannot " be a doubt^ I apprehend^ that it is in some " such way as this^ that children slowly and im- ^' perceptibly enter into the abstract and com- '' plex notions^ annexed to numberless words in " their mother tongue^ of which we should find " it difficulty or impossible^ to convey the sense " by formal definitions/^^ 100. In another place^ Mr. Stewart has de- scribed the manner of using induction^ in tracing an event to its physical cause. " As ^' we can^ in no instance^ perceive the link^ by '' which two successive events are connected;, so * Philosophical Essays, E^say V. ch, 1. INDUCTION. 81 as to deduce^ by reasoning a priori^ the one from the other^ as a consequence or effect^ it follows that^ when we see an event take place, which has been preceded by a com- bination of different circumstances, it is im- possible for human sagacity to ascertain^ whether the effect is connected with all the circumstances, or only with a part of them ; and, on the latter supposition, which of the circumstances is essential to the result, and which are merely accidental accessories or concomitants. The only way, in such a case^ of coming at the truth, is to repeat over the experiment again and again, leaving out all the different circumstances successively, and observing with what particular combinations of them the effect is conjoined.^^ " When, by thus comparing a number of ca- ses, agreeing in some circumstances, but dif- fering in others, and all attended with the same result, a philosopher connects, as a gen- eral law of nature, the event with its physical cause^ he is said to proceed according to th^ ^* method of induction.^^^ * Elements of the Pliilosophy of the Mind, vol. ii. ch.|4sec. 1. 83 iNDUCTio?>r. 101. Inductive conclusions will amount to moral certainty^ whenever our experience has been uniform, and the number of cases exam- ined, sufficiently numerous. But this reason- ing is liable to be fallacious through impatience in the investigation, by which judgments are hastily formed, without a sufficient accumula- tion of facts. The number of instances, re- quired to justify a general conclusion, must be increased in proportion, as the facts, from which we reason, are more irregular in their appearance. In judging concerning the prop- erties of inanimate matter, a general inference may sometimes be drawn from a small number of particular cases. If, for example, aqua for- tis has been known to dissolve silver in one in- stance, the presumption is very strong, that it will do so in all. But the success, which may happen to attend a medicine in a single instance, furnishes but a slight presumption with regard to its general operation on the human body. 102. When our experience has not been uniform, the conclusions we make will fall short of moral certainty. An equal number of fa- vourable and unfavourable instances leaves the mind in a state of suspeuse, without exciting ANALOGY. 83 the smallest expectation on either side. As the ratio^ which the instances on the two sides bear to each other, may vary indefinitely, so must the judgments, founded on them, vary in a like degree from the neighbourhood of cer- tainty, down to that of entire improbability.* CHAPTER FOURTH. ANALOGY. 103. Analogy is the foundation of another species of moral reasoning, similar in most re- spects to analytical induction. They both pro- ceed on the same general principle, that nature is consistent and uniform in her operations ; so that from similar circumstances similar ef- fects may be expected ; and in proportion as the resemblance between two cases diminishes, the less confidence must be placed in the con- clusions, made from the one to the other. The word, analogy, is used with much vague- ness. Sometimes it denotes only a slight and * Bacon, Novum Organiim. lib. i. Campbell, Phil. Rbet. vol. i. ch. 5, sect. 2. Beattie, Essay on Truth, part I. eh. 2. sect. 6. Tatham, Chart and Scale of Trutli, vol. i. ch. 4. sect 1. Stewart Elem. vol. ii. ch. 4. Gambler, Mor. Evidence, ch. 2. Scott, liiteL Phil. Appendix, ch. 2. 84 ANALOGY. distant resemblance; as that^ which is found between diiferent species of the same genus. Sometimes it implies a correspondence of dif- ferent relations ; as that^ which exists between the fins of a fish and the wings of a bird ; the latter bearing the same relation to the air^ that the former does to the water. 104. Inductive and analogical reasoning mk.^ so similar in their nature^ that it is not easy to point out their specifick difference. The fol- lowing circumstances appear to mark a distinc- tion^ sufficient to justify their being treated^ as separate articles. Firsts induction is a process from several individuals of a class to the whole. Its conclusions therefore are always general. But^ by analogy, we argue from one individu- al being to another of the same class ; and from one species to another. Secondly^ the evi- dence^ employed in analogy^ is wholly indirect and collateral ; — the coexistence of two quali- ties in one subject affording no direct evidence of their coexistence in any other. But in the inductive process we have direct evidence^ that the property^ which we apply to a whole class^ exists in many individuals of that class. It is true^ that in all induction analogy must be ANALOGY. 85 used ; for we can never separately examine every individual of a whole class^, however cautiously we may proceed. So far^ as we ex- tend our observations or experiments, the evi- dence is direct ; but with regard to the re- maining subjects of the classj, the conclusions must rest wholly on analogy. 105. Analogy is an unsafe ground of rea- soning; audits eonckisions should seldom be received^ without some degree of distrust. When things resemble each other in several important circumstances^ we are apt to sup- pose the similitude more extensive^ than it really is. The ancient anatomists^ being hin- dered by their superstition from dissecting the bodies of men^ endeavoured to obtain the in- formation^ which might thus have been deriv- ed^ from those quadrupeds^ whose internal structure was thought to approach nearest to that of the human body. In this v/ay they were led into numerous mistakes^ which have been detected by the anatomists of modern times. 106. The following is stated by Dr. Reid^ as an example of analogical reasoning. " We " observe a great similitude between this earth;> 86 ANALOGY. ^^ which we inhabit^ and the other planets^ Sa- ^^turn^ Jupiter^, and so forth. They all re- '* volve round the sun^ as the earth does ; ^' though at different distances and in different ^' periods. They borrow all their light from the " sun^ as the earth does. Several of them are " known to revolve round their axes^ like the ^^ earthy and by that means must have a like '' succession of day and night. Some of them ^* have moons^ that serve to give them light^ " in the absence of the sun^ as our moon does ^' to us. They are all in their motions subject " to the same law of gravitation^ as the earth ^' is. From all this similitude it is not unrea- '' sonable to think^ that those planets may^ like ^^ our earthy be the habitation of various or- ■'' ders of living creatures. ^^^ In the same manner we may conclude from analogy^ that the comets are inhabited. But this conclusion is less probable^ than the other^ in the same proportion^ as the comets have less resemblance to this earthy than the plan- ets have. 107. There are many subjects^ both specu- lative and practical^ about Vv^hich analogy is * Essays on Intellectual Powei^s^ Essay I. ch. 4. ANALOGY. 87 the only evidence we can employ. When a lawyer is perplexed with a case^ that falls not fairly within the provisions of any existing statute^ and for which his file affords no exact precedent^ he is placed under the necessity of tracing remote analogies and correspondences between this case and others within his knov/l- edge ; and of forming his method of procedure by the equivocal evidence^ furnished by such an investigation. To reason correctly on sub- jects of this nature often requires more caution and discrimination^ than are usually required in reasoning on the evidence of testimony or experience. ^^It is by the urging of different " analogies^ that the contention of the bar is '' carried on ; and it is in the comparison^ ad- ^^ justment^ and reconciliation of them with one " another, that the sagacity and wisdom of the " court are seen and exercised.^^* 108. Analogy^ on account of the uncertainty which attends its conclusions^ is rarely employ- ed in scientifick investigations. It serves to guide our judgments^, where direct evidence cannot be obtained ; and it affords a degree of probability^ which is sufficient for the prac- ^ Paley, Polit. PhU. ch. 8. 88 REASONING ON FACTS, tical business of life. The proper use of this instrument is to defend and illustrate truths^ already admitted on other evidence. It as- sists to explain ambiguities of language^ and to exhibit obscure truths in a clear and familiar light.^ CHAPTER FIFTH, REASONING ON FACTS. 109. A different mode of reasoning from eith« er of the preceding is used^ in the investigation of those important and interesting truths^ which are comprised under the general name oi facts. These are for the most part so unconnected and independent^ so transient in their exis- tence^ and so dissimilar in the causes^ which produce^ and the circumstances^ which attend them, that they cannot be deduced from any general principles of reasoning. The proofs, by which alone they can be established, must be derived from impressions, made on the senses * Locke, Essay on the Understanding, B IV. cli. 16. Camp- bell, Phil. Rliet. vol. i. B. I. ch. 5 sect. 2. Beattie, Essay on Truth, part I. ch. 2, sect, 7, Tatham, Chart and Scale of truth, vol. i. ch. 1, sect. 3. Stewart, Elem. Phil. Mind, vol. it qh. 4* sect 4. Gambler, Mor, Evid. ch» 2. REASONING ON FACT^, 89 of some persons^ to whose immediate observa- tion the facts themselves^ or some appearances, connected with them^ must have been present- ed. The truths^ belonging to this class form the largest and most valuable part of our knowledge. They enter into the business of human life ; and deeply involve the happiness both of individuals and communities, 110. Facts may be distinguished into three classes^ in reference to the evidence^ by which they are judged. Some are admitted on tes- timony alone ; some on circumstantial evidence alone ; and some on these two united. Firsts human testimony is the evidence^, on which we place most reliance for our knowledge of such facts^ as have not fallen under our im- mediate observation. We readily admit the reality of a fact on the sober declaration of a person, whose veracity we have no positive reason for distrusting. Truth is naturally agreeable to the human mind^ for people usu- ally speak, as they think. No effort of inven- tion is required to relate things as they are ; but arts of deception require study ; and are seldom practised, but for criminal purposes. The moral sense is rarely, if ever, depraved 90 REASONING ON PACTS» to such a degree^ as to lose all preference of truth to falsehood. 111. A propensity to believe what others assert has also its foundation in the constitution of the mind^ in the same manner as the tenden- cy to veracity. Children at first believe ev- ery thing, that is told them ; which is a wise provision^, as testimony is to them the princi- pal means of obtaining knowledge. This dis- position to unlimited credulity continues^ till experience begets distrust^ and at length teach- es the necessity of restraining our confidence in testimony within certain limits. 112. Testimony is either oral or written. Oral testimony is distinguished into original^ and transmitted or traditionaL It is original when it is derived from onej who had sensible evidence of the fact asserted. This is the on- ly testimony of this kind, in which we can have full confidence ; and^ when accompanied by cir- cumstances of the most favourable nature^ pro- duces a firm belief; even though it be the de- claration of a single witness. 113. When several independent original witnesses^ with equal advantages for knowing the fact;, which they assert^ and without any REASONING ON FACTS. 91 previous concert^ agree in their report^ they mutually strengthen each other^s testimony. This concurrence of several independent testi- monies is itself a probability^ distinct from that^ which may be termed the sum of the prob- abilities^ resulting from the separate testimo- nies of the witnesses ; a probability^ which would remain^ even though the witnesses were of such a character;, as to merit no confidence. That such a concurrence should be accidental is in the highest degree improbable. If there- fore concert be excluded^ there remains no other cause for the concurrence^ than the ex- istence of the fact. 114. That evidence^ which is professedljr given on a certain subject^ is called direct tes- timony. But a declaration^ uttered in famil- iar conversation^ or casually made in the course of a speech or discourse^ may be appli- ed as evidence on a subject in no way connect- ed with that^ on which it was originally intro- duced. This is termed incidental testimony^ and it is usually of greater validity than that^ which is direct ; because^ from the manner in which it was introduced; there is less reason 92 REASONING ON FACTS* to apprehend any deliberate intention to de- ceive, 115. When a witness asserts a fact^ which he did not personally observe^ but which he received from the mouth of some other person^ his testimony is called transmitted^ or tradition- al. The general principle with regard to this sort of testimony is^ that the further it travels from its original source^ that is^ from the im- mediate witness of the fact^ the weaker it be- comes. The existence of a fact^ reported by several persons in succession^ becomes a prob- ability, resulting from a series of probabilities^, successively founded on each other. Each per- son can affirm no more^ than what he received from his immediate informant^ and the channel^ through which the report was said to have pas- sed from the original witness to him. 116. The circumstances^ constituting what is called l\\€ credibility of a witness^ are the follow- ing. First^ sufficient discernment^ opportunity^ and attention^ to obtain a clear knowledge of the fact attested. Secondly^ disinterestedness^ which^ in its full extent^ implies the absence of all expectation of advantage or detriment, aris- ing from the testimony^ either to the witness IREASONING ON FACTS% 93 himself^ or to his friends^ sect^ or party. Thirdly^ integrity. This affords the strongest assurance of a true testimony, inasmuch as it is absohitely inconsistent with any intention to deceive or prevaricate;, as well as with a con- scious ignorance of the fact attested. To these may be added the sanction of an oath^ with a knowledge of its nature and of the high penalties^ annexed to perjury. But testimony under oath is principally confined to juridical proceedings. It is rarely employed in settling historical facts^ or the ordinary events of hu- man life. So far as a witness is deficient in either of the above qualifications^ so far will this deficiency invalidate his testimony. 117. Written testimony is usually esteemed stronger^ and more deserving of confidence^ than oral ; for the record^ being made for the most part without a knowledge of the uses^ to which it is afterwards applied^ may be presum- ed to have been made without any undue bias ; and the witness has more time to comtemplate the fact^ and weigh the circumstances^ so as to render his account accurate. Further^ as the record of facts is usually made soon after they occurred^ this testimony is secure against any 94 REASO:NnNG ON FACTS. suspicions^ arising from the imperfection of memory^ which often weakens the force of oral testimony^ especially on subjects of a distant date^ where circumstances are liable to be for- gotten^ and conjectures substituted in their stead. 118. Written testimony is also less liable to have its credibility impaired by transmission^ than oral. For^ as the original record is com- monly preserved for many years^ it may be compared with the successive copies^ and the slightest disagreement may easily be detected. Whereas oral testimony being fugitive in its nature^ the existence of the original witness can be proved only by the credibility of the second^ and the existence of this^ only by a j third^ and so on. Besides^ the care^ which copying requires^ gives a copy a preference to transmitted oral testimony. Mistake^ unless intentional^ is less likely to be committed. 119. If several independent copies be taken of an original record^ and these agree in all material circumstances^ their credibility^ with respect to the object testified^ is nearly equal to that of the original record. For it is highly probable^ that the different copies would sub- REASONING ON FACTS. 95 stantially agree; and scarcely possible^ that the same error should be committed in all. The same remark is applicable to all the successive copies^ and the more numerous they are^ the more they strengthen each other. 120. In all plural testimony^ whether oral or written^ the several witnesses are required to agree in every important circumstance. ' But in things of minor consequence^ a certain degree of discrepancy tends rather to increase^ than to diminish^ the credibility of the testi- mony ; for such a discrepancy is what must naturally be expected from different persons^ describing the same things. 121. General notoriety is a ground of be- lief^ extending both to specifick facts and gen- eral truths. It is a species of testimony differ- ent from either of the preceding in this^ that the information is not derived immediately or remotely from any one^ who pretends to have personally witnessed the fact^ or investigated the truth in question. No person can examine every subject for himself^ so as to have full knowledge of the truth of every proposition^ which he finds it necessary to believe. Many things must be received on trust. Most meu 96 REASONING ON FACTS. can give no better reason for their belief of the greatest part of the facts and general truths^ which they receive^ than that they find them universally believed by others. 122. The weight of this evidence depends partly on the presumption^ that unless the as- sertions were true^ their falsehood would have been detected ; and partly on experience ; for^ though we are in the constant practice of ad- mitting them^ as unquestionable truths^ we rarely find ourselves deceived. 123. This species of evidence should not be applied without discrimination. Mathematical subjects admit of being certainly known^ and mistakes respecting them may be easily correct- ed. In these therefore^ propositions^ univer- sally believed^ may be relied on with safety. The same may be observed of all assertions concerning the existence and qualities of ma- terial things ; and also concerning those facts and events^ which are subject to ihe observa- tion of many persons. But the case is differ- ent with respect to those propositions^ ♦ which^ if false^ could not be easily disproved ; such for example^ as relate to events^ which could have been observed only by a few persons ; or EEASONING ON t'ACTS. 97 to things^ supposed to have happened in re- mote antiquity, or in fabulous ages. Goieral notoriety or universal beliefs with regard to such propositions, is not a sufficient ground of as- sent. 124. Secondly^ there are many events and occurrences, which, as they happen not within the notice of any one, can be judged of only by a train of circumstances ; and this evidence often produces a higher degree of assurance;, than the testimony of living witnesses. Cir- cumstances can neither falsify, nor withhold the truth ; and an event is considered as well established, when a number of these are of such a nature, that they cannot be satisfacto- rily accounted for in any way, but by admit- ting the event in question. 125. Belief, grounded on circumstantial evi- dence, is usually A^nomiw^it^ presumption ; and presumptions are either slight or violent^ ac- cording as the circumstances noticed are more or less necessary to the fact supposed, or do more or less usually and exclusively attend it. Thus, the presumption, that a person is the author of an essay, barely because the hand writing resembles his, is only slight i for one 9 98 REASONING ON FACTS. person may imitate the hand of another^ and two persons may resemble each other^ in their usual manner of writing. But^ to render the presumption violent^ the circumstances must be such not only;, as w^ould necessarily have at- tended the fact^ had it existed ; but such as could not be supposed to have existed^ unless the fact in contemplation had existed likewise. Thus^ a cottage^ discovered on a desolate is- land^ affords a violent presumption^ that some human being had been there before. A shel- ter of some kind would be a natural, if not a ne- cessary consequence of a person's having resid- ed there ; and there is no other way^ by which the existence of the cottage can be accounted for. The fact^ on which a presumption is ground- ed^ must be clearly proved ; for a presumption cannot be raised on a mere conjecture. 126. Thirdly^ the credibility of attested facts may be heightened by the analogy of those facts to our general experience in similar cases^ or to w4iat reason would lead us to expect. This analogy is denominated internal evidence. Facts, which are rendered probable by inter- nal evidence, may have their probability in- KEASONING ON FACTS. 99 creased by testimony^ though in different de- grees. If an asserted fact agree with our con- stant and invariable experience^ its probability can be but little augmented by the most unex- ceptionable testimony. Thus^ the freezing of water is so common in our climate^ that^ should any person affirm^ that Charles river was froz- en over in February^ fifty years ago^ we could have no hesitancy in believing it. Nor would our assurance of the fact be increased^ by the united testimony of five hundred witnesses^ of the most undoubted veracity. 127. Where the internal probability is less^ more testimony is required to produce belief; as if it were asserted^ that there was thunder in May^ or frost in October in any particular year. These events^ happening not uniformly^ though much oftener than they fail^ receive but a slight confirmation from past experience. 128. Those facts^ which are called indiffer- ent or equicasualy by reason of the irregularity of their appearance^ belong exclusively to the pro- vince of testimony ; as, whether a ship sailed on Tuesday or on Friday ; whether a man made his willj or died intestate. The probability^ that any asserted fact of this sort happened at 100 REASONING ON FACTS. any specified time or place^ will be just equal to the credibility of the witnesses^ attesting it. 129. If the asserted fact be of an extraordi- nary nature^ and oiie^ that militates with our general experience in similar cases^ it will be assented to with difficulty ; as^ if it were as- serted^ that there was snow in August^ or that the same number drew the highest prize in five successive lotteries. The internal improbabili- « ty of such facts must be overcome by an in- creased weight of testimony. 130. Those facts or events^ which are ad- mit^ted with the greatest difficulty of all^ are sucb^BS are supernatural^ ov miraculous. These^ contradicting our invariable experience^ and opposing the well known laws of corporeal nsL- .tur% are in themselves in the highest degree improbable ; and require for their belief a tes- timony so ample^ and attended by such circum- stances^ as would render its falsehood no less miraculous^ than the fact attested.* * Gilbert, Law of Evidence. Kirwan, Logick, Part III. ch. 6. Locke, Essay on Understanding*, B, IV. ch. 16. Gambier, Mor- al Evidence, ch. 2, CALCULATION OF CHANCES. 101 CHAPTER SIXTH. CALCULATION OF CHANCES. 131. By chance is not meant the negation of a cause^ but our ignorance of it. Every change in the universe must proceed from some adequate cause. When we speak of events^ as happen- ing yor/^^if(9z/^/z/^ or by chanccy we mean no more^ than that the causes^ which produce them^ are wholly unknown to us. The bare possibility of an event is often denominated a chance ; and where there are several known causes equally capable of producing different events^ it is man- ifestj that there are so many chances of those events ; and that no one of them is more prob- able than the rest. 132. The doctrine of chances is that^ which teaches the degree oj* probability or improbahih ity of any one of a given number of events ^ con- sidered as equally possible. Thus^ on throwing a dicj it is certain that some one of its six fa- ces will be turned up ; bot^ as only one of these six faces can present an ace^ the chance of throw- ing an ace is only one out of six chances, or ^% and the chances against it are five out of six, or J- of a certainty. Hence the general rule 9^ 102 CALCULATION ^t CHANCES^ is^ that the probability or improbability of any event is^ as the number of the favourable chances^ divided by the sum of all the chances^ both fb- vourable and unfavourable. 133. The degree of probability^ that any event will or will not happen^, is conveniently expressed by a fraction;, whose numerator rep- resents the number of chances^ which favour the existence^, or the nonexistence of the event ; and whose denominator is the sum of all the chanceS;, both favourable and adverse to the event. Thus^ if an event have five chances to happen and three to fail^ the fraction |- will ex- press the probability of its happening, and the fraction |-, that of its failure. These two frac- tions, which represent all the chances both of happening and failing, being added together, their sum will always be equal to unity ; since the sum of their numerators wall be just equal to their common denominator. And as in every case it is certain, that an event will either hap- pen or fail, it follows, that certainty is justly represented by unity. 134. The expectation of obtaining a benefit, which depends on the happening of an uncer- tain ev^nt, has a determinate value before the CALCULATION Or CKANCES. 103 event takes place. The value of this expecta- tion is in all cases estimated by multiplying the value of the benefit expected^, by the fraction^ which represents the probability of obtaining it. Thus^ if 60 crowns be promised a person on condition of his throwing a particular face on a die^ his expectation before trial is worth 10 crowns, since he has one chance in six^ or |* of a certainty of gaining the whole sum. 135. Events are either independent or de- pendent. Two events are independtnt^ when they have no connexion xvith each other ^ and the happening of one neither promotes nor hinders the happening of the other. Thus^ throwing an ace on one die affects not the possibility of throwing it again on the same^ or on another die. But the possibility of ^ joint event on two dice^ though each is independent of the other^ singly considered;^ is affected by all the possi- bilities of failure in each of the conjoined events. Now there are thirty six possible events on two dice considered conjointly ; for each has six faceSj and each face of the one may be com- bined with each face of the other. Therefore the possible appearances are 6x6=1=36. But of these combinations there is but onC; pro^ 104 cittJutATION OF CHAXCE^. diictive of the appearance of two aces^ or any other two faces. So that the chance of throw- ing two aces either together on two dice, or successively on one die^ is only ~. 136. Hence the probability of two or more independent but joint events is equal to the product of the chances of each. Thus^ the prob- ability of throwing three aces successively on one die is -J x ^ X ■§- = ttt* ^^ ^^ ^^^ probabil- ity^ that one man^ A^ will live a year^ be -^^ and the probability of the life of another man^ B^ for one year^ be ~^ the probability^ that both will live another year^ is but -rs- X ~ == ■^^. Hence the concurrence of two events is less probable^ than the occurrence of either ; and is even improbable^ though each is probable and completely independent of the other. 137. From the foregoing rule it is manifest^ that the joint occurrence of two or more equi- teasual; independent events^ is improbable ; and tiie more so^ the more numerous they are. For ^the probability of each is -^ ; therefore the joint chance of two such events is ^-^ t- t5 ^^^^ ^^ three such events is 4- " -^ ^ - ~. So the con- currence of two independent^ improbable facts is still more improbable. For supposing the qALCULATION OF CHANCES. 105^ improbability of one of them to be -|^^ and that of the other -j^ their joint improbability would be -^. B)^ the same riile^ the improbability of the death of A within a year being -^-^^ and that of the death of B within a year —, the im- probability^ that both will die within a year^ ^s "ts-XiV-tI^- ^^d the probability that one of the events will happen and the other fail is^ as the probability of the happening of the one, multiplied by the probability of the failure of the other. So in the above case, the prob- ability, that A will live and that B will die, is ~ X -rs- = tVo • -^^d the probability, that B will live and that A will die, is ~ x tV = 3 a I o o* 138. A dependent event is one^ whose exist- ence is rendered more or less probable by the chances J attending the existence of another event. When several events are connected in such a manner, that the second depends on the first, the third on the second, and so on, the prob- ability of the first or independent event must be first ascertained ; that of the second, which depends on the first, is then found, by mul- tiplying its separate probability into that of the first 5 and the product will give the real 106 CALCULATION OF CHANCES. probability of the second event. In the same manner we proceed to find the probability of a third or fourth dependent event. 139. Thus^ suppose six white and six black balls to be placed in a box^ and^ through a hole in the box^ two balls to be successively drawn out ; and let it be required to determine the probability^ that both these will be white. As there are twelve balls in the box^ and six of them are white^ it is evident, that the proba- bility of drawing a white ball at the first trial will be ~. But the chance of doing this on the second trial will be difi'erent ; for^ as one of the balls has been taken out^ there are but eleven remaining ; and since^ in order to the second trials it is necessary to suppose^ that the ball removed was a white one^ the remaining number of these is reduced to five. The sep- arate probability therefore of drawing a white ball at the second trial will be only -^- ; and the chance of drawing it the first and second time will be ~z=i^x~'=--h:* "The separate probability of drawing out a white ball at a third trial^ since two white balls have been re- moved^ will be yV 5 ^^d the chance of drawing three white ones at three successive trials will be — >^ -^ X' -^ — a o 1 CALCULATION OF CHANCES. 107 140. Again^ W sailed for Africa in a fleet of twelve ships^ three of which were lost in a storm^ on the first part of the voyage. Of the crews of the nine ships^ that escaped the storm^ one third part perished from the hardships^ they met on the voyage ; we wish to ascertain the probability^ that W has escaped both ca- lamities. Now as the chance of his having sur- vived the hardships of the voyage depends on the event of his having escaped the storm, the probability of the last named event must be first ascertained. If this be found improbable^ the second event must fail ; but if it be found probable^ the second event may exist, and the probability of its existence may be found by the rule already given. [No. 138.] 141. As nine ships out of the twelve surviv- ed the storm, the probability that W escaped in one of them is yt=4- This being suppos- ed, the probability of his having escaped the second danger, since only one third of those^ who survived the storm, perished, is y. Hence the probability of his having lived through both dangers is ^ x y == yt = t- Therefore it is merely doubtful whether he survived both calamities. If only \ of the crew survived the 108 BEMONSTRATITE REASONING. second danger^ then his escape would be improb- able; for^x.^ = YV- I^ ^^^y ^^^^ out of the twelve ships were lost^ and consequentlj^ ten had escaped the first danger^ and ~ of the crew had escaped the second danger^ as above^ then the probability of his entire survival would be TT X T^ yl- - i ; a slight probability.^ CHAPTER SEVENTH. GENERAL DESCRIPTION OF DEMONSTRATIVE REASONING. 142. The general nature of demonstrative 7^easo?iing has already been explained^ in point- ing out the circumstances^ which distinguish it from moral^ or probable reasoning. See No. 87 to 93. It has generally been admitted^ that demonstration can be employed only about such truths^, as have been termed necessary^ the subjects of which are not supposed to have any real existence^ but to be abstractly conceived by the mind. All created beings depend on the will of their Creator. Their existence^ their properties^ and of course the relations^ subsisting among those properties^ are contin- * Demoivre, Doctrine of Chance.?, Iiitrodiictiom KIrv/aB, Logick, part III. cli. T. DEMONSTRATIVE HEASONING. 109 geiit^ and perpetually varying. Our reason- ing on these must be grounded on the observa- tion of our senses ; and the conclusions^ which we make, are liable to be uncertain. But de- iipionstrative reasoning, being grounded on exact and adequate definitions, and proceed- ing by the successive application of general propositions, which have an intuitive agree- ment with each other, affords satisfaction in every step ; and the mind advances to the conclusion with the fullest assurance of certain- 143. Demonstration is best adapted to the exact sciences of number and quantity. Arith- metick and geometry possess many important advantages with respect to this method of rea- soning. Their terms are free from all ambi- guity. Their first principles are simple and ob- vious. The subjects, about which they are conversant, are wholly independent of things in actual existence ; and capable of being per- fectly defined. The properties, belonging to these subjects, and their various relations, are necessary and immutable. These circumstan- ces impart to mathematical demonstrations a clearness and force, which cannot be obtained 10 110 DEMGNSTRATIVE REASONING. in other sciences. For these reasons many have maintained^ that demonstrative reason- ing can be used only within the precincts of mathematicks. Many others have controvert- ed this position ; and have contended^ that this method may^ at least occasionally^ be employ- ed in other sciences. 144. Mr. Locke advanced the opinion^ that moral subjects are as susceptible of demonstra- tion^ as mathematical. His reason for this opinion is thus stated in his Essay on the Un- derstanding.^ " The precise^ real essence " of the things^ moral words stand for^ may be " perfectly known ; and so the congruity or ^' incongruity of the things themselves be cer- '^ tainly discovered ; in which consists perfect " knowledge.'^ He adds^ " definition is the on- " ly way whereby the precise meaning of mor- ^' al words can be known ; and yet a way^ '' whereby their meaning may be known cer- " tainly^ and without leaving any room for con- " test.'^ In another placef he says^ ^^ the re- ^Hation of other modes may certainly be per- " ceived^ as well as those of number and ex- * Book III. ch. 11, sect. 16. t Book ly. ch. 3, sect. 18, DEMONSTRATIVE REASONING 111 ^^ tension ; and I cannot see why they should " not also be capable of demonstration^ if due '' methods were thought on to examine or pur- ^^ sue their agreement or disagreement.'^ 145. Dr. Reid distinguishes demonstrative reasoning into two kinds^ which are metaphy- sical and mathematical. ^^In metaphysical *^ reasoning^'' he observes^ '^ the process is al- ^' ways short. The conclusion is but a step or '^ two^ seldom more^ from the first principle or ^*' axiom^ on which it is grounded ; and the dif- ^^ ferent conclusions depend not one upon an- ^' other. It is otherwise in mathematical rea- ^' soning. Here the field has no limits. One ^' proposition leads to another ; that, to a third;, ^^ and so on without end. If it should be ask- ^^ ed^ why demonstrative reasoning has so wide ^^ a field in mathematicks^ while^ in other ab- ^^ stract subjects^ it is confined within very nar- ^^row limits ; I conceive this chiefly owing to" ^^ the nature of quantity ;, the object of mathe- '' maticks.^'^ 146. Demonstration^ in the customary sense of the term^ appears not to be absolutely cir- cumscribed by the narrow limits of a single * Essays on the Intellectual Powers, Essay VIL ch. 1. 112 DEMONSTRATIVE R:^AS0NING, science. Wherever the subjects of our reason- ing are independent on the existence of things^ and are of a nature to afford exact definitions and general propositions of undoubted certain- ty^ there this method of reasoning may be em- ployed. And it appears unnecessary to con- (iede, that these elements of demonstration are no where to be found^ except in the science of mathematicks. 147. Professor Scott^ speaking of Dr. Reid^s division of demonstrative reasonings says ; ''It " evidently cannot be meant by Dr. Reid^ that " metaphysicks is a science demonstrable in all ^^its partS;, like mathematicks. He was too '' well acquainted with the general uncertainty " of metaphysical speculations to have advano- '' ed such an opinion. If then he asserts only^ " that several metaphysical truths admit of '' demonstration^ the same ought doubtless to '' be said of physicks^ many of the reasonings " of which have at least as much of demonstra- " tive certainty, as any of the speculations of ^^metaphysicks. The truth appears to be, '' that every branch of science may occasionally " assume the demonstrative form. The exist- " ence of a Deity, the immateriality of the hu- DEMONSTRATIVE REASONING, 113 '' man soul^ and other moral or metaphysical " truths have perhaps been as fairly demon- " strated^ as the Pythagorean proposition^ or ^^the parabolick motion of projectiles. But ^^some sciences are much more susceptible of " this kind of proofj than others ; physicks ad- " mitting much more of demonstration^ than '^ metaphysicks^ or morals. Of all the sciences^ " mathematicks is that;, which admits the most " largely of demonstration. Its first principles " are so certain^ so definite^ and clear ; and its ^^ manner of proof so accurate and legitimate^ " that it may fairly be called a completely de- ^' moDstrative science^ and the only one^ which " is justly entitled to that name.^^'^ CHAPTER EIGHTH. DISTINCTIONS OF REASONING. 148. Reasoning is further distinguished in- to that^ which is a priori^ and that^ which is a posteriori. Reasoning a priori is that^ which deduces consequences from definitions formed^ or principles assumed ; or which infers effects from causes previously known. The books of * Elem. of Intell. FhiL ch. 8. sect. 4. 114 DISTINCTIONS OF REASONING* mathematicks afford numerous instances of con- clusions legitimately drawn from definitions and assumed principles. We also reason a priori whenever we judge of effects from a knowledge of the causes^ which produce them. Thus we infer^ that an eclipse of the sun and an eclipse of the moon can never happen with- in twelve days of each other^ from our knowl- edge of the causes^ which occasion those phe- nomena. 149. Reasoning a posteriori is the reverse of the former process. By this we deduce causes from effects. Thus we infer^ that the earth is spherical from its shadow on the moon in a lu- nar eclipse ; and we infer the being of a God from our own existence and that of the objects around us. All reasoning concerning the prop- erties and laws^ both of mind and body^ pro- ceeds on this principle. It is only by a care- ful observation of facts^ that the laws^ which regulate them^ can be discovered. 150. Another distinction of reasoning is^ in- to direct and indirect. The reasoning is direct^ when the proofs are so applied^ as to show im- mediately the agreement or repugnancy between the subject and predicate of the proposition in DISTINCTIONS OF REASOisTlNG. 115 question* In indirect reasonings the argU" ments^ which we employ^ are not intended primarily to show the relation between the terms of the proposi Lionel whose truth we would es- tablish ; but to prove the falsehood or absurd- ity of the proposition^ to which it is opposed. This method may be adopted, whenever it is manifest^ that the proposition;, which we allege^ or its contrary^ must be true. We may then prove the impossibility of the contrary propo- sition ; or we may show^ that a manifest ab- surdity must follow from admitting it ; and in either case we establish the truth of our orig- inal proposition. The former course is usually called a proof per impossibile ; and the latter^ a reduetio ad absurdum. 151. Mathematicians make frequent use of indirect reasoning. Thus^ Euclid proves by an indirect course^ that^ " if two circles touch " one another internally^ they cannot have the " same centre. ^^ He first supposes the contra- ry to be true^ namely^ that the two circles have the same centre ; and no third supposition can be made^ for they must either both have the same centre or not. He then demonstrates the impossibility of the case assumed 5 and thence 116 SYLLOGISTIC REASONING, infers the truth of the proposition^ which he first asserted. So moralists prove the existence of an all-wise and powerful Creator^, by tracing the absurdities^ which the contrary supposition involves, 152. Another form of indirect reasonings in frequent use^, is denominated reasoning a forti- ori. This consists in deducing a proposition^ as true^ from less obvious propositions^ embrac- ed by the same general principles. Thus^ if the felon^ who robs on the highway^ deserves the punishment of deaths this retribution is due a fortiori to the wretch^ who has committed parricide. CHAPTER NINTH. GENERAL DESCRIPTION OF SYLLOGISTICK REA- SONING. 153. All reasoning proceeds by comparison; and two comparisons are necessary to enable us to make a conclusion. The subject and pre- dicate of the proposition to be proved must be separately compared with some third term^ or common measure ; and from these comparisons we infer their agreement or repugnancy. This process, when expressed in words; consists of SYLLOGISTIC REASONING, 117 three propositions^ and has been termed syllo- 154. Syllogism was regarded for many centu- ries, as the only sure instrument of reasoning ; and skill in the use of it^ as the highest ac- complishment^ which the mind can possess. It derived its celebrity from the talents and indus- try of Aristotle^, who traced and analysed its principles^ subjected it to lawS;, and exhibited it in all the variety of modes and figures^ into which it could be moulded. Since the time of this philosopher^ the name^ syllogism^ has usu- ally been employed to denote an argumenti, framed according to certain technical rules of art. But it is sometimes used in a larger sense to imply any process of reasoning from more general to less general^ in opposition to the principle of analytical induction. In this sense^ it will apply to mathematical reasoning ; for all demonstrations in this science proceed on this fundamental principle of the syllogism^ that whatever may be ajffir^med of any genuSp may be affirmed of all the species^ included iin* der it. tiocinoi% computo. 118 SYLLOGISTICK REASONlK^G. 155. Syllogism and induction proceed in op- posite directions. Induction^, as has already been observed^ begins with individual objects^ as they exist in nature^ and ascends by succes- sive steps to the most general truths. Syllo- gism begins where induction terminates. It commences with some universal proposition^, and follows back the footsteps of the former process^ transferring at each stage the predi- cate of the more general^ to the less general rank of beings ; or^ in other words^ predicat- ing the genus of the species^ and the species of 4 156. The difference of these methods may be shown by the following example. We ob- serve that the individual people of our acquaint- ance are constantly dying around us ; that mei rarely live to the age of an hundred years^ and] that the former generations are wholly swept' from the earth. From these facts we infer^ that death is the common lot of our species. Observing also^, that the same fatality attends the various species of beasts^ birds^ and insects^ we deduce the more general conclusion^ that all animals are mortal. This inductive process^ reversed in syllogistick language^ would run thus ; SYLLOGISTICK REASONING. 119 All animals are mortal ; All men are animals ; Therefore all men are mortal. All men are mortal ; W. X. Y. are men ; Therefore W. X. Y. are mortal. 157. Syllogism is employed with advantage in communicating to others^ in an exact and perspicuous manner^ the general principles of science. It is also of service in exposing the weakness of arguments^ stated in loose or fig- urative language. But it is of no use in help- ing us to the discovery of new truths. We must know a thing firsts Mr. Locke observes^^ and then we can prove it syllogistically. 158. As syllogism operates wholly on gener- al propositions^ and definitions previously es- tablished^ the justness of its conclusions must depend ultimately on the accuracy^ with which the inductive processes have been conducted. " The syllogism/^ says Lord Bacon^ " is form- " ed of propositions ; propositions^ of w ords ; " and words are the marks of ideas. If there- " fore ideas themselves^ w^hich make the ground- "^^work of our reasoninQ:s9 are confused, and ' ESf:av,B. IV. ch. 17. 120 REGULAR SYLLOGISMS, ^^ formed from a hasty observation of things^ ^' the conclusions^ which we make from them^ ^' will be without solidity. The whole there- '' fore depends on the accuracy of our induc- ^' tions.'^^ CHAPTER TENTH. OF REGULAR SYLLOGISMS. 159. The most general division of syllogisms is into single and compound. Of single syllo- gisms some are regular and some are irregular. A regular syllogism is an argument^ consisting of three propositions^ the last of which is deduc- ed from the two preceding ^ and is substantially contained in them. Example. Every human virtue should be habitually practised ; Industry and temperance are human virtues ; Therefore industry and temperance should be habitually practised. 160. This is a concise and luminous method of evincing the agreement or repugnancy be- tween the subject and predicate of a proposi- * *^ Syllogismiis ex propositionibus constat ; propositiones, ex *' verbis; verba notionum tesseree sunt. Itaque si notiones ipsae, " id quod basis rei est, confusae sint, et temere a rebus abstractae^ ^' nihil in iis, quae superstruuntur, est iirmitudinis. Itaque spes est una in inductione vera," Novum Organum, Lib. 1 Apb. 14. e REGULAR SYLLOGISMS. 121 tioii. A third term^ having a common relation to them both^ is invented;, and applied to them successively^ in two distinct propositions. These are called "premisesj because from them the proposed question is inferred^ as a conclu- sion ; and its subject and predicate are either joined or separated^ according as they wer found in the premises to agree^ or not^ wi the term introduced. It is obvious^ that^ if any two things agree with a third^ they must agree xvith each other ; and that txvo things^ of which one agrees^ and the other disagrees^ with a thirdj must disagree with each other. The former of these rules is the foundation of all affirmative conclusions^ and the latter^ of all negative. 161. The names of the three propositions are the major^ the minor ^ and the conclusion. These are composed of three terms^ denominat- ed the major^ the minor ^ and the middle terms. The predicate of the conclusion is called the ma- jor termJ^ because it is the most general ; and the subject cf the conclusion^ the minor term^ because it is the least general. These two are also denominated the extremes ,- and the third * See note B, at the end of the book. 11 123 KEGULAR SYLLOGISMS. tenuj introduced as a common measure be- tween tliem^ is called the mean or middle term^ because its extension is less than that of the major, and greater than that of the minor term. [See No. 35.] This circumstance proves the natural situation of the middle term to be that of subject in the major premise^ and of predi- cate in the minor ; since the predicate of a proposition is never less^ but usually more gen- eral^ than the subject. 162. In forming the syllogism^ each term is taken twice^ and no more. The middle and major terms constitute the major premise ; the minor and middle terras^ the minor premise ; and the two extremes^ connected by a copula^ make tip the conclusion. The major proposition must always be universal^ but may be either affirmative or negative ; and the minor prop- osition must always be affirmative^ but may be either universal or particular.^ The conclu- sion may be either universal affirmative^ uni- versal negative^, particular affirmative^ or par- ticular negative. 163. In every regular syllogism^ the major proposition is placed first ; the minor, next ; * See note C^ at the end of tlie bcolc. REGULAR SYLLOGISMS. 123 and the conclusion^ last ; as in the following example. Every vegetable is combustible ; Ever J tree is a vegetable ; Therefore every tree is combustible. Combustible is the major term ; every tree^ the minor term ; and these extremes are joined in the conclusion. Vegetable is the middle term ; it is subjected in the major premise^ and pre- dicated in the minor. The major premise must always be sufficiently general to involve the conclusion ; and must be assumed^ as a truth already known. It cannot be proved by syllo- gism. This instrument teaches only how to make a legitimate inference of one proposition from another. 164. The truths proved by the preceding example^ is^ that trees are combustible. The major premise^ namely, every vegetable is com- bustible, is first assumed on the ground of ex- perience and observation. The minor premise barely asserts the fact, that trees belong to the class of vegetables. Now if it be certain, that combustion belongs universally to vegetables, and that trees are included in that class of things, it must of necessity follow, that every 124 ItlEGULAR SYLLOGISMS. tree is combustible ; for it is a primary law of syllogistick reasonings that vjhatever 7nay be affirmed of any general term^ may he affirmed of every species and individual^ included within its extension. 165. In the regular syllogism^ each step of the reasoning process is distinctly expressed ; but in familiar language^ one part is frequent- ly omitted^ which rnay be readily found by ex- amining the grounds;^ on which the judgment is formed. Thus^ No language is perfect ; Because it is a human invention. Perfection is here denied of language^ for no other assigned reason^ than because it is a hu- man invention. But there is a latent propo- sition^ which is the real ground of the judg- ment^ and must therefore have been distinctly contemplated by the mind^ namely^ no human invention is perfect. Let this proposition be subjoined to the other two^ and the argument will read thus ; No language is perfect ; Because it is a human invention ; And no human invention is perfect. This is the regular syllogism reversed j which, rectified^ will read thus ; REGULAR SYLLOGISMS* 125 No human invention is perfect ; Every language is a liuman invention ; Therefore no language is perfect. 166. Every assertion^ accompanied by a reason why it is made^ contains the elements of a syllogism^ namely^ the major^ minor^ and middle terms. Every such assertion^ made in the familiar form of language^ may be trans- ferred to a regular syllogism^ by observing the following rule. First^ distinguish the reason^ on which the attribute of the given proposition is affirmed^ or denied of its subject^ and this will be the middle term of the syllogism. Let this be taken;, in its most enlarged sense^ for the subject of a proposition^ to which^ for a predicate, unite the attribute of the asserted proposition^ and the major premise will be formed. Next, to form the minor premise^ we have only to predicate the middle term^ already found, of the subject of the asserted proposition. The original pjroposition^ without the reason^ before annexed to it; will constitute the conclu- sion of the svlloQ;ism. 167. For example. Dr. Johnson says of en- vy. '* It is; above all other vices, inconsistent ^Svith the character of a social being, because 11^ 126 REGULAR SYLLOGISMS. " it sacrifices truth and kindness to very weak ^' temptations/^ Sacrifices truth and kindness to very weak temptations is the reason^ why envy is pronounced^ above all other vices^ inconsis- tent with the character of a social being. This then must form the middle term of the syllo- gism. But as this collection of words repre- sents an attribute^ and not a person or thing really existing^ it cannot be enlarged^ so as to become the subject of a general proposition^ by simply placing before it one of the common signs of universality^ all^ every ^ or each; it must be preceded by some universal sign of a different sort^ as xvhatever^ that ivhichy or the like. Thus ; That, which sacrifices truth and kindness to very weak temptations, is, above all other vices, inconsistent with the character of a social being ; Envij sacrifices truth and kindness to very weak temp- tations ; Therefore envy is, above all other vices, inconsistent with the character of a social being. In this maimer may the simple elements of reasonings however obscured^ in any instance^ by rhetorical language^ or complicated forms of speech, be easily collected, and exhibited in a regular syllogism. REGULAR SYLLOGISMS. 127 168. As the major proposition of a syllogism must always be universal^ the middle term^ as the subject of this pro ^osition^ must be taken in a universal sense. Every middle term must represent either some class of persons or things^ or else some attribute common to a whole class of beings. If the middle term denote persons or things,, something must be asserted hypo- thetically^ in the major proposition^ to agree with^ or to be repugnant to that whole class of beings ; and in this class the minor term must be included ; which it is the sole business of the minor proposition to affirm. In the conclu- sion^ we apply to the minor term^ separately^ the same predicate^ which was applied to it in the major proposition^ in connexion with the whole class of things^ to which it belongs. 169. If the middle term express an attri- bute^ it must be asserted in the major propo- sition^ that^ to whatever person or thing the attribute^ forming the middle term^ can be as- cribed^ the major term may be ascribed also* In the minor proposition^ the attribute^ which forms the middle term^ is declared applicable to the minor term. In the conclusion^ the a- greement or repugnancy^ which was before ad- 128 REGULAR SYLLOGISMS. mitted between the middle and major terms^ must be also admitted between the major and minor terms. 170. Any regular syllogism may be reduced to the familiar form of reasonings by the follow- ing rule. First; state the conclusion^ omitting the illative^ therefore ; then^ subjoin the middle term together with the minor^ or some pronoun as its substitute^ preceded by some causal particle; as since^ for^ or because. For exam- ple; Every animal, possessing wings and feathers, is a bird ; An ostrich is an animal, possessing wings and feathers ; Therefore an ostrich is a bird. This syllogism may be thus expressed in the familiar form of reasoning ; An ostrich is a bird ; Because it has wings and feathers. 171. Each of the preceding syllogisms con- cludes with a universal proposition. The con- clusions of the four following examples are of different kinds. I. Whoever disregards the rights of his fellow beings, deserves the detestation of mankind ; Tyrants disregard the rights of their fellow beings ; Therefore tyrants deserve the detestation of mankind. REGULAR SYLLOGISMS. 129 II. They, who subvert the foundations of morality and religion, ought not to be respected 5 Atheists subvert the foundations of morality and religion ; Therefore atheists ought not to be respected. III. Every creature, which can live in more elements than one, is amphibious ; Some animals can live in more elements than one; Therefore some animals are amphibious. IV. No person of dissolute habits can be a safe companion ; Some persons of improved minds are dissolute in their habits ; Therefore some persons of improved minds are not safe companions. The conclusion of the first syllogism is a universal affirmative proposition ; that of the second^ a universal negative 5 that of a third^ a particular affirmative ; and that of the fourth, a particular negative. These are all the kinds, into which propositions are distinguished, in reference to quantity and quality.^ ^ Common systems of logick. Collard, Logick, part IV. ch. 4, 5, 130 IRREGULAR SYLLOGISMS. CHAPTER ELEVENTH. ENTHYMEMES, 172. Besides the regular^ categorical syllo- gism^ described in the preceding chapter^ tliere are some other kinds of single syllogisms^ which have different degrees of irregularity in their construction. Among these may be placed the enthymeme^ which is an abridged;, or defective syllogism^ consisting of the conclusion and on- ly one of the premises ; the other being sup- pressedj as too obvious to need insertion. It is of very general use^ both in writing and con- versation. 173. Which of the premises is omitted in any instance may be known^ by the following rule. If the subject of the conclusion be ex- pressed in the given premise^ or proposition^ con- taining the reason^ the major premise is omit- ted ; if the predicate of the conclusion be ex- pressed^ the minor premise is wanting. Thus^ Whatever tends to subvert the civil government, should be deprecated ; Therefore civil dissensions should be deprecated. Christianity teaches the way to future happiness ; Therefore It should be diligently sought. IRREGULAR SYLLOGISMS. 131 The minor premise is omitted in the first ex- ample^ and the major in the second. Let these be supplied^ and the syllogisms will be complete. Whatever tends to subvert the civil government should be deprecated ; Civil dissensions tend to subvert the civil government ; Therefore civil dissensions should be deprecated. That knowledge, which teaches the way to future happi- ness, should be diligently sought ; Christianity teaches the way to future happiness ; Therefore Christianity should be diligently sought. 174. Enthymemes may be expressed in va- rious ways^ and have sometimes been distin- guished into several kinds. Those are the most regular^ which conform to the syllogistick order. In these the conclusion is placed after the proposition, which contains the proof, and^ by supplying the omitted proposition, the syl- logism is rendered perfect, without any other alteration. But, in familiar conversation, it is more common to express the conclusion first, and then to subjoin the reason, on which it is grounded, preceded by a causal particle. As^ Enthusiasm should be avoided ; Because it leads us astrav from reason. 132 IRREGULAR SYLLOexISMS. They, who deny a future state of retribution, are in error ; For tliey deny the doctrine of the bible. 175. Although the conclusion be placed af- ter the reasoning proposition^ still the enthy- meme will not be regular^ unless the syllogis- tick language and arrangement be employed. The following sentence is an enthymeme of this sort; " Since it is the understanding, that sets men above the "rest of sensible beings, and gives him all the ad- " vantage and dominion, which he has over them ; " Jif: is certainly a subject, even for its nobleness, worth " our labor to inquire into.'^* Each of these enthymemes contains the ele- ments of a syllogism^ namely^ the major, minor^r and middle terms ; which may be easily distin- guished. The suppressed propositions are readily supplied by the mind ; and the omis- sion of them contributes to the brevity and elegance of language. 176. An act of reasoning may be stated hypothetically ; thus, The African slave-trade should be discountenanced ; ijf 1^ be a violation of i\iQ natural rights of man. ^ Locke^ Essay, Introduction. IRREGULAR SYLLOGISMS* 133 Here the predicate^ discountenanced^ is not applied to the African slave-trade absolutely ; but only on condition of its being a violation of man's natural liberty. Still the reasoning is the same^ as if it were expressed in this abso- lute form ; The African slave-trade is a violation of the natural rights of man ; Therefore it should be discountenanced by all. The judgment is formed in the two cases by a comparison of precisely the same things, 177. What are here considered^, as familiar enthymemes^ have usually been received^ as compound propositions^ and have been distrib- uted into different species^ under the heads of causal^ discretive^ and conditional, But^ that they cannot justly be regarded^ as mere prop- ositions of any sort^ is evident from this^ that each example contains two entire propositions. [See No. 80.] It is equally manifest^, that they represent complete acts of reasonings since in each the elements of a perfect syllogism are expressed.^ ^ Collard, Logick, part IV. ch. 6. 12 134 IRREGULAR SYLLOGISMS, CHAPTER TWELFTH. CONDITIONAL AND DISJUNCTIVE SYLLOGISMS. 178. ^ conditional^ or hypothetical syllogism is one^ whose major proposition is conditional. Thus^ If men have vicious propensities, they need the restraints of government; But men have vicious propensities ; Therefore they need the restraints of government. The major premise consists of two entire prop- ositions^ which make an enthymeme. The minor premise and the conclusion constitute another enthymeme^ expressing the same mean- ing as the other^ with only this difference^ that what is stated hypothetically in the firsts is expressed absolutely in the last. The first part of the major, containing the condition, is called the antecedent ; and the last, which con- tains the conclusion, the consequent. If the antecedent be admitted in the minor premise, the consequent must be admitted in the conclu- sion ; for the condition, stated in the antece- dent, must always be such, as necessarily to re- quire the truth of the consequent. By the same necessity it will follow, that, if the conse- IRREGULAR SYLLOGISMS. 135 querit be contradicted in the minor^ the ante- cedent must be contradicted in the conclusion. Thus, If death be an eternal sleep, the scriptures are not true ; But the scriptures are true ; Therefore death is not an eternal sleep. 179. In conditional syllogisms then there are two ways of reasoning, which lead to certain conclusions. The first is called arguing from the position of the antecedent to the position of the consequent; and the other, arguing from the removal of the consequent to the removal of the antecedent. These are the only modes of true reasoning in this sort of syllogism, for we are not at liberty to adopt the contrary course, and argue from the admission of the consequent to the admission of the antecedent ; nor from the removal of the antecedent to the removal of the consequent. This will be man- ifest in the following example. If W. were a general, he would have power; But W. is not a general ; Therefore he has not power. If W. be a general, he must be obeyed ; But W. must be obeyed ; Therefore he is a general. 136 IRREGULAR SYLLOGISMS, [ai^j' The falsehood of the consequent will not fol- low from the falsehood of the antecedent ; nor the truth of the antecedent^ from the truth of the consequent. The one may be true^ and the other may be false for different reasons from those;, which are assigned. 180. ^ disjunctive syllogism is one^ whose major premise is disjunctive. Thus^ The world is either self-existent, or the work of some finite, or of some infinite being ; But it is not self-existent, nor the work of any finite being; Therefore it is the work of an infinite Being. The business of the major proposition of this syllogism appears to be^, to enumerate several predicates^ of which one only can belong to the subject. If then the minor establishes one of these predicates^ the conclusion must remove all the rest ; or if^ in the minor premise^, all the predicates but one are removed^, the conclusion must establish that^ which remains. This pro- cedure has been denominated arguing from the assertion of one to the rejection of the rest ; or^ from the denial of one^ two^ or more^ to the establishment of the remainder. But the term^ arguing^ is applied to it without any good rea- COMPOUND SYLLOGISMS. ISf son ; since it is nothing more^ than a formal and circuitous method of stating a fact. CHAPTER THIRTEENTH. COMPOUND SYLLOGISMS. 181. A compound syllogism consists of more than three propositions ; and may he resolved into two or more syllogisms. Of these the prin- cipal kinds are the Epichirema^ Dilemma^ and Sorites. The Epichirema is a compound argument^ of which the major and minor premises are sep- arately proved^ before the conclusion is drawn. Example. Unjust laws endanger the stability of government ; for they create discontent among the people ; Laws, which restrain the freedom of conscience, are un- just ; for they require people to abandon their dear- est concerns ; Therefore laws, which restrain the freedom of conscience, endanger the stability of government. The major and minor premises^ v^ith their respective proofs^ form two enthymemes^ which may readily be reduced to regular syllogisms^ Discard these proofs^ and a regular syllogism will remain. 13S COMPOUND SYLLOGISMS. 182. The epichirema is much used in con- versation^ puhlick harangues^ and oratorical discourses. Cicero^s defence of Milo is an argu- ment of this sort. His first position is^ that it is lawful for one man to kill another^ who lies in wait to kill him. This he proves from the laws of nature and the customs of mankind. His second position is^ that Clodius lay in wait for Milo^ with a murderous intent ; which he proves by his equipage^ arms^ guards^ and other circumstances. Then he infers the conclusion^ namely^, that it was lawful for Milo to kill Clodius* 183. The Dilemma"^ is a compound argument^ which establishes a general conclusion^ either directly by proving its necessity ^ or indirectly by showing the impossibility or absurdity of its contrary^ in every supposeable case. Thus^ Every magistrate must either execute the laws, or suffer them to be violated ; if he execute them, he will be hated by the vicious and profligate; If he suffer them to be violated, he will be hated by the wise and virtuous ; Therefore, every magistrate is exposed to hatred from his fellow men. * A/5, his^ and > G.lbert, Law of Evidence. PoUiier on obi ig-at ions. De* mat on the civil law. 168 CONCLUDING REMARKS. count of the categories^ together with the vari- ous laws of syllogistick reasonings may be found in the logical treatises of Burgersdicius and of Le Clere. Of modern systems of logick^ those of Watts and of Duncan have been most approved. A more recent and valuable treatise, than either of thescj is that of Kirwan. It is essential to accurate reasoning to dis- tinguish those first principles of human knowl- edgCj which must be taken for granted^ from those propositions^ which require proof. On this subject the treatise of Father Buffier^ en- titled First Truths, Beattie^s Essay on Truth^ and Condillac on the Origin of Knowledge^ are valuable sources of information. The Novum Organum of Lord Bacon con- tains in a small compass those rules of induc- tive logick^ which have been followed with the happiest success^ both in physical researches^, and in the philosophy of the mind. On the subject of moral reasonings important information may be derived from Gambier's Introduction to Moral Evidence^ and from the first book of CampbelPs Philosophy of Rhet- crick. CONCLUDING remauks. 169 For the general direction of the mind^ in its researches after truth^ rules of a more practi- cal nature may be found in Lockers Conduct of the Understandings and Watts on the Im- provement of the Mind. The study of those authors^ who reason clearly and accurately^ is one of the best meth- ods of improving the reasoning powers. For this purpose^ Berkeley on the Principles of Human Knowledge^ Wollaston on the Religion of Nature^ and Baxter on the Soul^ may be read with great advantage. The catalogue might easily be extended^ if it were thought necessary. It will be concluded by referring the student to the metaphysical writings of Locke^ Reid^ Stewart;, and Brown. They may be consulted with great benefit^ on each of the subjects above mentioned ; and may be said to comprise in themselves a complete system of intellectual philosophy. But the student should remember^ that nei- ther learning the best rules, nor reading the best models, can supersede the necessity of intent and continued reflectian. "He should dwell on the operations of his own mind, and mark the difficulties, which prevent his arriving at clear 15 170 CONCLUDING BEMAEKS. conclusions ; whether they arise from misappre* hension of the subject^ from the ambiguity of language^ from weakness in the power of at- tention^ or from the biasses of association. He will thus insensibly form a logick for himself, which^ while it embraces the rules, common to all minds, will be peculiarly adapted to the improvement of his own* in NOTES AND ILLUSTRATIONS, JVote K^ page 17. I have used reflection and consciousness as sjnony- mous terms, and they are so used by eminent writers on pneumatology. Some however have considered them as denoting operations specifically different. Dr. Reid says, ^* reflection ought to be distinguished from consciousness, with which it is too often confounded, even by Mr. Locke. AH men are conscious of the operations of their own minds, at all times while they are awake, but there are few who reflect on them, or make them the objects of their thought. Though the mind is conscious of its op- erations, it does not attend to them ; its attention is turn- ed solely to the external objects, about which those op- erations are employed." Essay \ston Intel, Powers, \\\ another place he says^ that*' attention to things external is properly called observation, and attention to the sub- jects of our consciousness, reflection.'' This definition of reflection is substantially the same with that of Mr. Locke, which I have used. The foregoing passage from Dr. Reid points out a dif- ference in degree, rather than in kind, between conscious- ness and reflection. It is true that the bulk of mankind ir£- . NOTES, pay very little attention to their mental operations. But without some degree of attention, they would have 310 consciousness of them whatever; and so far as they do attend to them, so far, according to Dr. Reid's own account, they reHect. The only way, by which the phenomena of the mind can be investigated, is by attending to its successive changes and operations, as they are passing; and this reOex act of attention is nothing more than an effort of the mind to increase or prolong the consciousness of its own acts. Reflection on any operation of the mind presupposes the actual existence of that operation. It may be examined afterwards by the assistance of mem- ory, but this subsequent examination cannot be denom- inated reflection, agreeably to the strict sense of that word. Are we then to believe that reflection and consciousness are tw^o distinct simultaneous efforts; and each of them different from the operation, which the mind is carrying on at the same time? This would oblige us to consider the mind, not as simple, but as a complication of different powers or agents, one of which may be employed in w atching the operations of another, while its own acts are examined by a third. Dr. Reid defines reflection, "attention to the subjects of our consciousness.'^ By this expression he evidently supposes consciousness and the subjects of consciousness to be different things. But the mind can be conscious only of what passes within itself. Consciousness then^ according to him, means the notice, which the mind takes ©f its own operations. Now as he places reflection m NOTES. 173 attention to the subjects of our consciousness, and it ap- pears manifest, that by the subjects of consciousness he means nothing else than the operations of the mind, it follows, even from his own statement, that these terms are but different names for the same thing. In common use there seems to be a slight difference in the import of these terms. By consciousness is com- monly understood barely the mind's notice or percep- tion of its own acts and modes of existence. But reflec- tion is usually employed to express some degree of vol- untary attention to the phenomena of the mind, in order to ascertain the laws, by which it is governed. As the bulk of mankind have no curiosity for such speculations, they have been said rarely, if ever, to reflect. JVote 3, page 121. Logicians have, from the earliest period denominated the predicate of the conclusion the major term, and its subject, the minor. The only reason, assigned for doing this, is, that the predicate of a proposition has a wider extension than the subject. But this is not a sufficient reason for calling it the major term, since in all our affirmations and negations we are invariably governed by the comprehension of terms, without the slightest re- gard to their extension. We assert' the more general of the less general for this manifest reason, that the former is a part of the latter. We predicate the genus of the species, but not the species of the genus. The predicate 15"^ 174 NOTES. of a proposition is only an attribute of the subject; and* in this light it must be viewed, in order to render the proposition true. When, for example, we affirm that saffron is yellow, we refer a single property to a subject, in which it is known to coexist with several other proper- ties. In doing this, we are guided by our knowledge of that plant, without inquiring what other bodies there are in existence, which have a yellow color. And we pro- ceed in the same way, when the predicate has no greater extension than the subject, as vyhen we affirm that iron is susceptible of magnetical attraction. In passing from one rank of beings to another, in the order of their classification^ we observe that each supe- rior class stands in the next below it. Thus we may say a mastiff is a do X Oo ^ J o '^ o .^^ \> ^ ^ ^ /- "> O^ .- S ^ '^ " ' «. .V t^^ ' O. ■ 0^^ , c J> ,<. G^ ^ <^ ^ H ^ ^V x^^^ .5 ^'^c^ .^^i^^ll^ .0 o <' "-^ ^ H "^ Deacidified using the Bookkeeper process. '^ Neutralizing agent: Magnesium Oxide Treatment Date: Sept. 2004 ^■^f^ vV 9 ; •^ ^^ '^> ., ^ '°./. * , . ^ ,^ ^ ^- V ^'i/>. a)S PreservatioiiTechnologies -, A WORLD LEADER IN PAPER PRESERVATION S 111 Thomson Park Drive Cranberry Township, PA 16066 (724) 779-21 1 1 ^nmiMiiiiuJ ^ ■% „ \) n. \. ^ o r> \ ^ ^:^^ '(\i/A X Oo '^^ rO .\^^ cP- ■^ 5' MHI >^. (^ -^. 1' -^S