< 
 
^iLtmmtmmmmmmmmmmmKmm wammmm ■■■■■■i ■■■■■■■■■■■ ■■■ ■■■■ 
 
 LIBRARY OF THE 
 
 University of California. 
 
 CIRC UL A TING B R A N C Jf . 
 
 taarweekjTj W a week before the end of the term. 
 
 *■ 
 
i 
 
 
ELEMENTS 
 
 LOGICR; 
 
 OR 
 
 A SUMMARY OF THE GENERAL PRINCIPLES 
 
 AND DIFFERENT MODES 
 
 REASONING. 
 
 BY LEVI HEDGE, EL. D. 
 
 PROFESSOR OF NATURAL RELIGION, MORAL PHILOSOPHY, AND CIVIL FOLITr, 
 IN HARVARD UNIVERSITY. 
 
 STEREOTYPE EDITION^ J V fg 
 
 '4£ft 
 
 Boston: 
 
 PUBLISHED BY IIILLIARD, GRAY & CO. 
 
 1835. 
 
-& 
 
 o 
 
 ©» 
 
 \A^ 
 
 DISTRICT OF MASSACHUSETTS, TO WIT : 
 
 District Clerk's Office. 
 
 B« it remembered, That on the fifteenth day of September, A. D. 1827, and in 
 the fifty-second year of the Independence of the United States of America, Levi 
 Hedge, of the said District, has deposited in this office the title of a book, the right 
 whereof he claims as author, in the words following, to wit i 
 
 " Elements of Logick; or a Summary of the general Principles and different Modes 
 of Reasoning. By Levi Hedge, LL. D. Professor of Natural Religion. Moral Phi- 
 losophy, and Civil Polity, in Harvard University." 
 
 In conformity to the act of the Congress of the United States, 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 men- 
 tioned :" 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 benefits thereof to the arts of designing, engraving 
 and etching historical and other prints." 
 
 JOHN W. DAVIS, 
 Clerk of the District of Massachusetts. 
 
 "isr^us 
 
 Stereotyped at the 
 Boston Type and Stereotype Foundry. 
 
PREFACE 
 
 TO THE FIRST EDITION. 
 
 Most of the treatises of Logick in common use have 
 been formed on the model of the ancient systems, and 
 are encumbered with many scholastick. subtilties and 
 unimportant distinctions. The instructions, which they 
 furnish on the subject of ratiocination, consist of very 
 little more than a description of the syllogism, and a 
 few general principles of demonstrative reasoning. They 
 contain no elements nor rules to assist us in reasoning 
 on subjects of probability, or on the ordinary events of 
 human life. The manner, in which these books are writ- 
 ten, is ill adapted to the comprehension of young minds. 
 In explaining the operations of reasoning, many technical 
 terms and arbitrary forms are employed, of which the 
 tendency is rather to embarrass and perplex, than to in- 
 struct the learner. 
 
 Though much has been written, of late years, on the 
 powers and operations of the mind, yet there haeve been 
 but few attempts to form a system of Logick for the use 
 of those, who are commencing* the study. Collard has 
 improved the syllogism, by simplifying 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 
 

 4 
 
 IV PREFACE. 
 
 which Nature teaches us to analyze the objects, which 
 she presents to our observation. In " An Essay on the 
 Elements, Principles, and different Modes of Reason- 
 ing," 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 be 
 used as a text book id 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 elementary, and better accommodated to 
 the present improved state of the philosophy 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 
 principles of every species of reasoning, which we have 
 occasion 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 neces- 
 sary 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. 
 
PREFACE. V 
 
 Under these impressions, the writer of this compend 
 has pursued the following plan. After passing through 
 the customary distinctions of terras and propositions, he 
 has given a brief account of moral evidence, and pointed 
 out the circumstances, which distinguish it from demon- 
 strative. A concise view is then given of the different 
 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, Locke's 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, 
 Belshara'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 
 hoped, 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, Nov. 1821. 
 
CONTENTS. 
 
 PART FIRST. 
 
 A DESCRIPTION OF THE LEADING AFFECTIONS AND 
 OPERATIONS OF THE MIND. 
 
 Pago 
 
 Introduction. 13 
 
 CHAP. I. 
 Perception and Consciousness . 15 
 
 CHAP. II. 
 Attention 19 
 
 CHAP. III. 
 Comparing 21 
 
 CHAP. IV. 
 Abstraction 23 
 
 CHAP. V. 
 Association 25 
 
 CHAP. VI. 
 Analysis 28 
 
 PART SECOND. 
 
 OF TERMS AND PROPOSITIONS. 
 
 CHAP. I. 
 Logical Distinctions of Terms e . 31 
 
X CONTENTS. 
 
 CHAP. II. 
 Definition and Division 39 
 
 CHAP. III. 
 General Description of Propositions 43 
 
 CHAP. IV. 
 
 Simple, Complex, and Modal Propositions. ... 47 
 
 CHAP. V. 
 Quality and Quantity of Propositions 60 
 
 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. II. 
 
 Difference between Moral and Demonstrative 
 
 Reasoning 70 
 
 CHAP. III. 
 Induction 76 
 
 CHAP. IV. 
 Analogy 83 
 
 CHAP. V. 
 ReasoDing on Facts. 88 
 
CONTENTS. XI 
 
 CHAP. VI. 
 Calculation of Chances 101 
 
 CHAP. VII. 
 
 General Description of Demonstrative Reasoning. 108 
 
 CHAP. VIII. 
 Distinctions of Reasoning. . . . • 113 
 
 CHAP. IX. 
 
 General Description of Syllogistick Reasoning. . 116 
 
 CHAP. X. 
 Regular Syllogisms 120 
 
 CHAP. XI. 
 Enthymemes 130 
 
 CHAP. XII. 
 Conditional and Disjunctive Syllogisms. .... 134 
 
 CHAP. XIII. 
 Compound Syllogisms 137 
 
 CHAP. XIV. 
 Sophisms 144 
 
 CHAP. XV. 
 Disposition or Method 149 
 
 CHAP. XVI. 
 Rules of Controversy. 157 
 
 CHAP. XVII. 
 Rules of Interpretation 162 
 
 Concluding Remarks ... 168 
 
 Notes and Illustrations* ....•••• 171 
 

^5 
 
 fOFIVF 
 
 ELEMENTS OF LOGICK. 
 
 PART FIRST. 
 
 A DESCRIPTION OF THE LEADING AFFECTIONS AND OPERA- 
 TIONS OF THE MIND. 
 
 INTRODUCTION. 
 
 1. The purpose of Logick is to direct the 
 intellectual powers in the investigation of truth, 
 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 
 simple 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 
 terms, and distinguishes their various kinds. 
 It teaches the nature and varieties of propo- 
 sitions ; explains their properties, modifica- 
 
 2 
 
14 INTRODUCTION. 
 
 fions, 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 in- 
 capable of any high degree of improvement, 
 without the aid of rules and principles, yet 
 these are insufficient without practice and ex- 
 perience. 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 ;i brief description of the lend- 
 ing powers and operations of the mind : The 
 second, of the several kinds of terms and prop- 
 ositions. The third comprises an explanation 
 of moral and demonstrative evidence; of the 
 different modes of reasoning ; of sophisms ; 
 and of method, or disposition. 
 
 CHAPTER FIRST. 
 
 PERCEPTION AND CONSCIOUSNESS. 
 
 5. Perception is the first state or affection 
 of 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, 
 seeing, feeling, hearing, 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 in- 
 tercourse proceeds, we have no knowledge. 
 From experience we learn, that a sensible 
 alteration takes place in the mind, whenever 
 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. 
 
16 PERCEPTION AND CONSCIOUSNESS. 
 
 The word perception denotes the knowledge, 
 that we gain by sensation, of some quality in the 
 object ;* 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 
 imperfectly, the ideas, received from it, are 
 liable to be faint and indistinct. But the usual 
 effects 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 external 
 a objects, and the ])erceptions of material qualities, which follow 
 " those sensations, are to be distinguished from each other only 
 " by long habits of patient reflection." Stewart, Elem. vol. i. ch. v. 
 part 2d, sect. 1st. 
 
PERCEPTION AM) CONSCIOUSNESS. 17 
 
 of sense, that so few of the objects, which 
 strike our senses, leave any durable traces in 
 the mind ; and that those notions, which do 
 remain, are so often obscure and indistinct. 
 As the perceptions of sense are the first ele- 
 ments of 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, 
 icJiich the mind takes of its own operations, 
 and modes of existence* By this we are 
 made acquainted with the successive changes, 
 which take place in the state of our minds. 
 Consciousness is similar to perception, though 
 the qualities of body, which are the objects of 
 the latter, bear no resemblance to the thoughts 
 and operations of the mind, which are the 
 objects of the former. The mind, at least 
 whilst we are awake, is constantly employed 
 in some mode of thinking, or in some exertion 
 of its powers ; and all the operations, passions, 
 and affections of the mind, are necessarily 
 subject to its own observation. Thus, by 
 
 * See note A, at the end of the book. 
 
18 PERCEPTION AND CONSCIOUSNESS. 
 
 consciousness, we learn what is expressed by 
 the words compare, reason, doubt, assent, joy, 
 in the same manner as, by perception, we gain 
 a knowledge of sweet, green, soft, cold. 
 
 3. Both perception and consciousness^ consid- 
 ered apart from any acts of attention, accom- 
 panying 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 like, without 
 being conscious of those states. 
 
ATTENTION. 19 
 
 4~ 
 
 CHAPTER SECOND. 
 
 ATTENTION. 
 
 9. Attention expresses 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 act. Its surprising 
 influence, in improving the perceptive powers, 
 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, who 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 
 epicures acquire an uncommon sensibility in 
 tasting and smelling ; and blind persons im- 
 prove the sense of feeling to such a degree, as 
 to make it, in some measure, supply the want 
 of sight. These effects are produced chiefly 
 by an increased and habitual attention, which 
 
 * A seafaring life, especially when early commenced, has a ten- 
 dency to produce some physical change in the organ of vision. 
 
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 mind, 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, 2 
 Reid, Essays on the Active Powers, Essay II. ch. 3. 
 
 
COMPARING. 21 
 
 " in matters of mere judgment and reasoning, 
 " 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 earth, in a mo- 
 " mcnt. 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 THIRD. 
 
 COMPARING. 
 
 12. When the mind contemplates two things 
 in reference to each other, it performs the 
 operation 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 IT. ch. 3. 
 
22 COMPARING. 
 
 We make comparisons with the greatest ease, 
 and frequently without being conscious of them. 
 It is only by this operation, that we are enabled 
 to recognise the objects, which we have before 
 known, or to give to any quality or object an 
 appropriate name ; for the application of the 
 name requires not only the sensation, produced 
 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, which 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 into 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 -nine time 
 leada«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 compari- 
 sons. »,/ 
 
 \h 
 
 CHAPTER FOURTH. 
 
 ABSTRACTION. 
 
 14. Abstraction literally implies the separa- 
 ting of one tjaing from another ; but, as a 
 mental operation, it denotes only a partial 
 consideration of any thing. It is the act of 
 considering one or more of the properties or 
 circumstances of an object, apart from the rest. 
 Thus we may consider the length of a bridge, 
 without regarding its breadth or construction. 
 We may speak of fluidity in water, hardness in 
 marble, 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 numerous 
 subjects, the name applied to it becomes a 
 general term. So whiteness stands for the 
 
i>4 ABSTRACTION. 
 
 colour of snow, milk, chalk, 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 re- 
 quired a distinct operation, which they called 
 generalization. Dr. Reid says, "we cannot 
 " generalize without some degree of abstrac- 
 " tion, but I apprehend we may abstract without 
 " generalizing. For what hinders me from at- 
 " tending to the whiteness of the paper before 
 "me, without applying that colour to any other 
 " object ? The whiteness of this individual 
 " object is an abstract conception ; but not a 
 " general one, while applied to one individuai 
 " only. These two operations, however, are 
 
 * Reid, Intellectual Powers, Essay V. ch. 3. Collard, Logick, 
 part I. ch. 2. 
 
ASSOCIATION. 
 
 "subservient to each other; for the more at- 
 " tributes we observe and distinguish in any 
 
 "one individual, the more agreements \ve 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 passed 
 the first years of life, after a long absence, will 
 recall many interesting events of childhood. 
 The first notes of a familiar tune, being sound- 
 ed, will cause the remaining notes to pass 
 through the mind in regular order. 
 
 17. No principle of our nature is productive 
 of more important effects, than this, which 
 
26 ASSOCIATION. 
 
 establishes a connexion between our ideas, 
 feelings, 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 gov- 
 ernment and other institutions of our country. 
 It is to the principle of association, that we are 
 to attribute our predilections for the modes of 
 dress, pronunciation, and behaviour of those, 
 whom we esteem and respect. 
 
 The principles of association have been dif- 
 ferently stated. Their number is not settled ; 
 but the following are among the most obvious : 
 
 18. First, 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 another 
 principle of association, but of less extensive 
 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 as- 
 sociation, is continuity or nearness of lime 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 w T ere 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 we have formerly travelled, successively 
 remind us of the subjects, about which we were 
 employed, when wif passed them before. 
 
 21. A fourth principle of association re- 
 sults from the relations of cause and effect, 
 premises and consequences. The sight of a 
 . surgical instrument, or an engine of torture, 
 excites a strong sense of the pain, it is calcu- 
 lated to occasion ; and the sight of a wound 
 reminds 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 se- 
 veral 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 
 successively 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. i. Scott, 
 Elem. Intel. Phil. ch. v. sect. i. 
 
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 us, consist of assemblages of different 
 
 qualities, some more and others h ily dis- 
 
 tinguished. Children early become acquainted 
 with the distinguishing properties of the thii 
 daily offered to their senses, and in a 
 years find out the characteristic k marks of 
 numerous classes of things, and learn the use 
 of Ian sni a^e. 
 
 24. Things, which have no immediate re- 
 ference to material objects, such as thoughts, 
 affections, 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 
 into 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 
 
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 causes 
 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 chymist and botanist retrace the pro- 
 cesses of nature, and ascertain the qualities of 
 mineral and vegetable substances. 
 
 Analysis will be further considered under 
 the head of Inductive Reasoning.* 
 
 * Condillac, Logick, part i. Watts, Logick, part iv. ch. 1. Stew- 
 art, Elem. vol. ii. ch. 4. 
 
PART SECOND. 
 
 OF TERMS AND PROPOSITIONS, 
 
 CHAPTER FIRST. 
 
 LOGICAL DISTINCTIONS OF TERMS. 
 
 26. Words possess no natural aptness to 
 denote 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 Mane, denote 
 the same colour. 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 asso- 
 ciation, formed to be the subject or predicate 
 of a proposition ;* as, human fortitude, a swift 
 
 * See ch. 3. 
 
32 TERMS. 
 
 horse, an amiable deportment. A word, which 
 denotes several individuals of the same sort, is 
 called a collective term ; as, army, forest, drove. 
 28. Secondly, terms arc distinguished into 
 absolute and relative. An 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 in- 
 dividual, denominated, in reference to him, 
 son. These two terms, intimating each other, 
 by a reciprocal reference, are called correlative. 
 So patron and client, husband and wife, guardian 
 and ivard, are correlative terms. 
 
 There are other relative terms, as who, 
 which, it, that, and the like, which barely 
 recall certain other words, before mentioned ; 
 hence the words they refer to are denominated 
 antecedents. 
 
 29. Thirdly, terms are distinguished into 
 univocal, equivocal, and synonymous. Univocal 
 terms are such as have invariably the same 
 signification annexed to them. Thus individual- 
 
 
TERMS. S3 
 
 it ii, genus, electricity, are uni vocal terms : 
 for they always signify the sumo things. 
 Equivocal words are such as are employed in 
 different senses. Of this sort is the word head, 
 which may signify a part of a nail, of an 
 animal, 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 
 distinct name for every idea. Notwithstanding 
 this, we sometimes find two or more words 
 applied 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 signifies some quality or attribute, without 
 referring to any subject, 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, and 
 the attributes indirectly ; and sometimes the 
 reverse Thus philosopher, statesman, me- 
 
34 TERMS. 
 
 chanick, 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 
 universal. 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- 
 
TERM 3. 35 
 
 mon. 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 language, 
 happily contrived to facilitate and expedite 
 the intercourse of society. Every production 
 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 re- 
 taining under distinct names those, which are 
 common, we reduce to a limited number of 
 classes the innumerable objects, which fall 
 under our observation. This distribution of 
 things into classes forms what logicians call 
 the genera and species of things. 
 
 34. Species denotes a sort or class, including 
 only individuals , and genus a class including 
 under it tico or more species. A species is 
 formed by applying a name to that property, 
 or collection of properties, in which many 
 
36 TERMS. 
 
 individuals are found to agree. Thus man is a 
 species ; for the name is applicable to an in- 
 definite number of individual beings, on account 
 of their agreeing in the essential properties 
 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 different 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, 
 elephant, and many other species. So bird 
 is a genus, of which eagle, lark, swan, and 
 sparroiv, 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 thing, or class 
 of things, to which it is applied. Thus gold 
 includes in its comprehension a material sub- 
 stance, a yellow colour, superior weight, 
 ductility, fusibility, and every other known 
 property of that body. The extension oj a term 
 regards the number of individual subjects, to 
 which it may be applied. So the term gold 
 
TERMS. 37 
 
 includes in its extension every separate parcel 
 of that metal. Man includes in its extension 
 every individual of the human race. 
 
 36. Classes arc multiplied as the conveni- 
 ence of language is found to require ; nature 
 having affixed no limits to the number, that 
 may be formed. As the number of classes 
 increases, the names, which express them, 
 become more complicate in their signification, 
 and less extensive in their application to indi- 
 viduals. 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. 
 
38 TERMS. 
 
 37. The ranks, which lie above any class, 
 or which embrace a wider extension, are 
 called, in reference to it, superior ; and that, 
 which terminates the series, is called most ge- 
 neral, 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 species, 
 according as it is considered in the ascending 
 or descending series. Thus bird is a genus, 
 when referred to eagle, raven, sparroiv, but 
 a species, when referred to the more general 
 term, animal. 
 
 38. The genus next above any species is call- 
 ed 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 collection 
 of properties, by which any species is distin- 
 guished from every other species of the same 
 genus, is the specif ck difference. So juice 
 is the proximate genus of wine ; but the cir- 
 cumstance of being pressed from grapes is the 
 
DEFINITION. 39 
 
 specifick difference, which distinguishes wine 
 from cider and perry, which are also juices.* 
 
 CHAPTER SECOND. 
 
 DEFINITION AND DIVISION. 
 
 39. Definitions are usually distinguished into 
 two kinds : one nominal, or of the name ; 
 the other real, or of the thing. A definition 
 of the name is merely a specification of the 
 object, to which a name is applied. A definition 
 of the thing is properly an analysis of a thing, 
 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 Understanding, b. iii. ch. 3. Reid, Essays, 
 vol. ii. essay v, ch. 1. Belsham, Logick, part i. sect. 4 and 5. 
 Kirwan, Logick, part i. ch. 2, 6ect. 2. 
 
40 DEFINITION. 
 
 colour of gold or saffron. Surprise is the 
 passion, or state of mind, produced by the 
 perception of some new or uncommon object. 
 
 41 . A real definition leads us to a knowledge 
 of the nature of a thing, 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 another's 
 rights. Real definition includes the nominal ; 
 for an explanation of the nature of any thing 
 necessarily fixes the signification of the name, 
 by which it is called. Natural substances, and 
 all compound beings, whether real or imaginary, 
 are susceptible of real definitions. 
 
 42. Logicians divide a definition into two 
 parts, which 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 proxi- ' 
 mate genus, denoting what bird has in com- 
 mon with horse, deer, elephant ; the other 
 terms denote the specifick difference ; for they 
 
DEFINITION. 
 
 point out the properties, which distinguish 
 bird from every other species of animate. So 
 square is a figure, which has four equal sides, 
 and four right angles. Figure is the proximate 
 genus ; the other terms make the specifick 
 difference. 
 
 43. If the thing to he defined 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 in- 
 dividual from all others of that species. Thus 
 Mercury is the planet nearest the sun. Planet 
 is the lowest species ; nearest the sun is 
 the circumstance, which sufficiently marks a 
 difference between Mercury and the other 
 planets. x 
 
 44. There are many words in every lan- 
 guage, which cannot be defined, because they 
 have no uniform signification affixed to them. 
 The, this, that, which, such, every, good, had, 
 desirable, and the like, are nearly insignificant 
 sounds, till they are applied to particular 
 things, from which they borrow a sort of local 
 or temporary meaning : and they often signify 
 different things, when applied to different 
 subjects. Good, applied to a soldier, means 
 
 4* 
 
42 DEFINITION. 
 
 courage ; to a Christian, piety ; to a physician, 
 skill ; to a horse, strength ; to a knife, sharpness. 
 
 45. Words of this description, which have 
 no uniform signification affixed to them, are 
 wholly employed in the definition of other 
 terms. The definitive particles have no other 
 use, than to restrain the latitude of general 
 terms. For example, the man, this horse, that 
 tree, such an object. Here the names man, 
 horse, tree, and object, which represent whole 
 classes of things, are restrained, by the words 
 the, this, that, and such, to certain individuals, 
 with which we are supposed to be already 
 acquainted. 
 
 Again, a wide river, a severe winter, a de- 
 lightful 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 restrained 
 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. 
 Thus a tree is divided into trunk, roots, and 
 
PROPOSITIONS. 43 
 
 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 
 consideration 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 
 opposed, that one will not be contained in 
 another. The parts, into which any thing is 
 first divided, should be the largest and most 
 general. The resolution of one of these parts 
 into others, 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 
 introduce confusion.* 
 
 CHAPTER THIRD. 
 
 GENERAL DESCRIPTION OF PROPOSITIONS. 
 
 47. A proposition is a verbal representation 
 of some perception, act, or affection of the mind. 
 
 * Locke, Essay, b.iii. Watts, Logick, part i. Kirwan, Lcgick, 
 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, thing, or 
 attribute. 
 
 48. The subject of a proposition is that, con- 
 cerning which something is either asserted, de- 
 nied, commanded, or inquired. The predicate is 
 that, which is asserted, denied, commanded, or 
 inquired, concerning the subject. The copula is 
 that, by which the other two parts are connected. 
 
 Body is divisible. 
 Man is not omniscient. 
 Be ye filled. 
 Is Caesar dead ? 
 
 Body, man, ye, and Ccesar, 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 
 inquired for. 
 
PROPOSITIONS. 
 
 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 ii 
 
 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 w T as existent. The copula is always 
 some inflection of the verb to be, either express- 
 ed or understood. 
 
 A single word may contain a complete pro- 
 position. Thus scribo implies ego sum scribens, 
 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 
 order 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 one, whose 
 subject and predicate are composed of the same 
 word or ivords, 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 
 residence. 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 PROPOSITIONS. 
 
 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 it, and after- 
 wards distinctly expressed ; as in the following 
 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 it, which 
 being discarded, and the subject stated first, 
 the proposition will stand thus : 
 
 To guess at the term, to which our forbearance would 
 have extended, is impossible. 
 
 54. Another manner of rendering a proposi- 
 tion complex is by introducing the pronoun 
 ivho, which, or that, for the purpose of explain- 
 ing 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 which it is 
 placed. 
 
 55. Lastly, any proposition is complex, 
 whose subject or predicate is defined, by an- 
 nexing to- it a word of limitation, or restriction. 
 As, 
 
PROPOSITIONS. 49 
 
 Upright men are respected. 
 The mind is a simple substance. 
 
 The subject of the first example is defined by 
 the word upright ; and the predicate of the 
 second, by the word simple. These words re- 
 strain 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 one, whose copula 
 is qualified by some word or words, representing 
 the manner of the agreement or discrepancy 
 between the subject and predicate. The modal- 
 ity of propositions is frequently expressed by 
 the auxiliary verbs, may, can, must, ought, and 
 the like, which imply possibility, necessity, or 
 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 barely 
 5 
 
50 QUALITY AND QUANTITY 
 
 the nature of that agreement ; namely, that it 
 is possible or necessary.* 
 
 CHAPTER FIFTH. 
 
 QUALITY AND QUANTITY OF PROPOSITIONS. 
 
 57. Propositions are further distinguished 
 into affirmative and negative ; which has been 
 called a distinction with respect to quality. In 
 affirmative propositions, the predicate and subject 
 are asserted to agree. As, 
 
 Clovis was the 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 negative par- 
 ticle not immediately after the copula. Thus, 
 
 The world is not eternal. 
 
 58. Sometimes the negative particle is placed 
 so far from the copula, that it appears to have 
 no immediate connexion with it ; but rather to 
 belong to some other part of the proposition : 
 
 Not all the troops united were able to defend the 
 fortress. 
 
 * Watts, Logick, part ii. ch. 2. Kirwan, Logick, part i. ch. 2. 
 
OF 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 made evident by stating the proposition 
 thus, 
 
 All the troops united were not able to defend the 
 fortress. 
 
 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 or particular. 
 A universal proposition is one, whose subject is 
 a general term, used in the whole of its extension. 
 The signs of universality are all, each, every, 
 no, neither, and the like. Thus, 
 
 All 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 declared 
 applicable. 
 
 60. When the sign of universality is omit- 
 ted, or the indefinite article is placed before 
 
52 QUALITY AND QUANTITY 
 
 the general subject, the proposition is called 
 indefinite. Thus, 
 
 Planets are continually changing their places. 
 
 A just sovereign regards the welfare of his subjects. 
 
 These subjects are taken in their greatest 
 extent ; 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 particular proposition is one, whose 
 subject is a general term, but is taken only in a 
 part of its extension. The signs of particular- 
 ity are some, many, most, several, few, and the 
 like. 
 
 Some 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 
 proper name, of some individual person or 
 thing, is denominated singular. As, 
 
OF 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 which reason 
 singular propositions are classed with universal. 
 Every proposition, therefore, is either universal 
 or particular. 
 
 63. Besides this quantity in the subject, 
 there is another quantity in the predicate of 
 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.] In all affirmative 
 propositions the predicate is particular : and in 
 all negative propositions it is universal. 
 5* 
 
54 QUALITY AND QUANTITY 
 
 64. The predicate of an affirmative propo- 
 sition, separately considered, is commonly a 
 more 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 
 subject. It is taken in the whole of its 
 comprehension, but in a part only of its ex- 
 tension. [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 predi- 
 cate, not being restrained by a subject, to which 
 
OPPOSITION AND CONVERSION 55 
 
 it is declared inapplicable, is taken in the 
 whole of its extension. Thus, 
 
 No animal is a tree. 
 
 This proposition implies, that the things, 
 included 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 dis- 
 agreement 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 
 opposed. 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 
 called contrary. As, 
 
56 OPPOSITION AND CONVERSION. 
 
 Every disease is contagious. 
 No disease is contagious. 
 
 Thirdly, a particular affirmative may be oppos- 
 ed to a particular negative. These are called 
 subcontrary. 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 ; two contraries may be both false, but 
 they cannot be both true ; and two subcontra- 
 ries may be both true, but they cannot be both 
 false, at the same time. 
 
 67. The conversion of a proposition is Ike 
 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 conversion. But if, 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 
 
 / 
 
OF PROPOSITIONS. 57 
 
 denominated convcrsio per accidens. Universal 
 affirmative propositions are usually convertible 
 only in the latter mode ; but universal negatives 
 and particular affirmatives are convertible in 
 the former. 
 
 63. 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 proposition particular. Thus, 
 
 Orig. Prop. All swallows are birds. 
 Converse. Some birds are swallows. 
 
 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 proposi- 
 tions, the subject and predicate are reciprocal terms. As, four times 
 jive are twenty ; and ticcnty are four times fire. Wine is the juice 
 of the grape ; and the juice of the grape is wine. 
 
58 OPPOSITION AND CONVERSION. 
 
 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 
 inconvertible in any mode. Its subject is par- 
 ticular, and by conversion this subject would be 
 made the predicate of a negative proposition, 
 and must therefore be universal, according to 
 No. 65 ; a whole deduced from a part, which 
 is impossible. For example ; from this propo- 
 sition, 
 
 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, 
 
 Orig. 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 affirmative. t 
 
 CHAPTER SEVENTH. 
 
 COMPOUND PROPOSITIONS. 
 
 73. A compound proposition is one, which has 
 two or more subjects, or predicates, or both ; and 
 may be resolved into two or more 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 and predicate are both particular ; and in a particular 
 negative, the subject only is particular, and the predicate universal. 
 
 t Watts, Logick, part li. ch. 2. Kir-wan, Logick, part i. ch. 3 
 
60 COMPOUND 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 year, and the four predicates of the last, 
 
 separately applicable to the subject, Alfred, 
 
 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 
 apply, and predicates, to which the whole sub- 
 ject 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 distinct 
 propositions. 
 
 75. Two or more words are sometimes 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 
 resolved 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 independent 
 of each other, and may be taken separatelv. 
 as well as conjointly ; which is not the case 
 in complex propositions. In the latter, either 
 certain words are joined together, which re- 
 present 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 proposition 
 is repeated, directly or implicitly, by some 
 relative word, as, it, that, icho, which ; or, lastly, 
 the real subject or predicate is defined by an 
 explanatory word. In either of these cases, 
 6 
 
52 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 any one 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 given, belong to the 
 first class. 
 
 A disjunctive proposition asserts, that a sub- 
 ject agrees ivith one of two or more named pred- 
 icates, or a predicate with one of two or more 
 subjects enumerated ; but does not specify which. 
 
COMPOUND PROPOSITIONS. 63 
 
 Thus, 
 
 Either the sun or the moon will be eclipsed, on Christ- 
 mas day. 
 
 The weather will, at that time, be either clear or 
 cloudy. 
 
 19. A discretive proposition consists of tire 
 parts, which are contratsed by reason of some 
 apparent opposition or inconsistency ', intimated 
 by the particles but, 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 
 essential to the individuality of a proposition, 
 that it have but one copula. However com- 
 pounded or complicated the subject or predicate 
 may be, they must be connected by a single 
 affirmation or negation. This rule is violated 
 in every instance of what are called condition- 
 al, 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 no one of them can, 
 with any propriety, be considered as a com- 
 pound proposition. Each example consists 
 of two entire propositions, possessing distinct 
 subjects, copulas, and predicates ; and so put 
 together as to constitute a complete act of 
 ratiocination.* 
 
 * Collard, Logick, part iii. ch. 2. Kirwan, Logick, part i. 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 mind, uniting 
 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 with other objects, to which 
 they have a known relation. The former is 
 simple comparison ; the latter is an act of 
 reasoning. The determination of the mind in 
 both cases is denominated judgment. Every 
 act of judgment is grounded on some sort of 
 evidence. That, which determines the mind in 
 simple comparison, is called intuitive evidence ; 
 and that, which is employed in reasoning, 
 deductive. 
 
 6* 
 

 66 INTUITIVE EVIDENCE. 
 
 The principal kinds of intuitive evidence, of 
 sources of intuitive belief, are the evidence 
 of sense, of consciousness, of memory, and of 
 axioms, or general principles. 
 
 82. The first source of intuitive belief is the 
 testimony of the external senses, hearing, 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 prudence, 
 which relate to the preservation and health of 
 our bodies, must ultimately be resolved into 
 this principle, that things are as our senses 
 represent them. 
 
 
INTUITIVE EVIDENCE. 
 
 67 
 
 83. Consciousness is another source of in- 
 tuitive evidence. Its office is to inform us of 
 the present existence of our various passions, 
 affections, and mental operations. The whole 
 science of the human mind is huilt on this evi- 
 dence ; and no branch of knowledge stands on 
 a surer foundation ; for no evidence is superior 
 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 
 intellectual operations, are liable to err in apply- 
 ing 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 
 advances towards maturity. Some* have 
 supposed it to be wholly dormant during the 
 years of childhood. It is however exercised, 
 in a greater or less degree, by people of all 
 classes ; and the subjects, about which it is 
 employed, 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, whether 
 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 causes, 
 which 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 
 assent 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, 
 they must weaken our confidence in the con- 
 
INTCITIVK KNIDr.NCF. 69 
 
 elusions, to which they arc subservient. Unless 
 therefore the evidence of memory he admitted 
 as a ground of certain knowledge, the founda- 
 tion of demonstrative reasoning would be 
 destroyed. 
 
 86. 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 ichole is greater than a part. Things 
 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 cJuld 
 be deduced. In all demonstrative reasoning, 
 constant use is made of these abstract and 
 self-evident propositions.* 
 
 * Bcattie, Essay on Truth, part i. ch. 2. Stewart, Elem. vol. ii. 
 ch. 1. Campbell, Phil. Rhet. vol. i. ch. 5. Scott, Elem. Intel. 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, ivhich ar-e 
 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 de- 
 duced from observation and experience.* De- 
 monstrative evidence is that, by which we trace 
 the relations, subsisting among things, in their 
 nature immutable, like the subjects of geometry 
 and arithmetick. On this distinction of deduc- 
 tive evidence is founded the most general divi- 
 sion of reasoning, which is into moral or proba- 
 
 * Gambier, Moral Evidence, ch. 1. 
 
DEDUCTIVE EVIDENCE. 71 
 
 ble, and demonstrative. The principal differences 
 in these modes of reasoning arc 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 
 moral reasoning are matters of fact, which 
 are in their nature contingent, and the varia- 
 ble connexions, which subsist among things in 
 actual existence. Thus, that mercury may be 
 congealed Ly cold, that lead is fusible, that 
 Hannibal led an army over the Alps, that Lisbon 
 was once destroyed by an earthquake, and the 
 like, are truths within the province of moral 
 reasoning. 
 
 88. Secondly. In a demonstration, it is not 
 necessary to examine more than one side of 
 the question ; for if any proposition be demon- 
 strated to be true, whatever can be offered, as 
 proof, on the opposite side, must be mere fal- 
 lacy. But in cases of moral reasoning, there 
 
 > 
 
V 
 
 72 DEDUCTIVE EVIDENCE. 
 
 are frequently arguments of weight on both 
 sides ; and therefore, in order to judge cor- 
 rectly, we must consider each side of the 
 question, 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 
 urged 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 suspense by the conflict of opposite 
 reasons. 
 
 89. Thirdly. Propositions, contrary to those 
 established by moral evidence, are merely 
 false ; but those, which are contrary to de- 
 monstrated propositions, are not only false, but 
 likewise absurd. Thus, the assertion, that 
 Carthage was never taken by the Romans, 
 though false, is not absurd ; for there was a 
 time, when it was true. But the assertion, 
 that the opposite angles, formed by two straight^ 
 
DEDUCTIVE EVIDENCE. 73 
 
 lines crossing each other, arc not equal, is not 
 only false, but also absurd. 
 
 90. Fourtbly. 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, we 
 feel in the conclusion, must depend on the 
 degree, 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 which 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, when 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, there is usu- 
 ally a combination of many separate arguments, 
 in no degree dependent on each other. Each 
 
 7 
 
74 DEDUCTIVE EVIDENCE. 
 
 possesses some weight, and bestows on the 
 conclusion a certain degree of probability ; of 
 all which, accumulated, the credibility of the 
 fact is compounded. Thus, the proof, that the 
 Romans once possessed Great Britain, is made 
 up of a variety of independent arguments : as, 
 immemorial tradition ; the testimony of histo- 
 rians ; the ruins of Roman buildings, camps, 
 and walls ; Roman coins, inscriptions, and the 
 like. These are independent arguments ; 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 reasoning, 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 reasoning, 
 the processes are usually short, 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 associa- 
 tions. 
 
DEDUCTIVE EVIDENCE. 75 
 
 93. It should be remarked here, that the 
 epithet probable, as applied by logicians to the 
 evidence of moral reasoning, has a teennical 
 meaning, altogether different from its usual 
 signification. In common discourse, it is ap- 
 plied to evidence, which does not command a 
 full assent ; but in logical discussions, it has a 
 more comprehensive meaning, 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 proof, but as contradistinguishing one species 
 of proof from another ; — not as opposed to what 
 is certain, but to what may be demonstrated 
 after the manner of mathematicians ; — not as 
 denoting the degree of evidence, but its nature. 
 It is the more important to keep in mind this 
 distinction between the popular and technical 
 meaning of the term probable, as the neglect 
 or misapprehension of it has given origin to 
 a distrust of moral reasoning, as inferior in 
 evidence to mathematical demonstration ; and 
 induced many authors to seek for a mode of 
 proof altogether unattainable in moral inquiries ; 
 
./ 
 
 76 INDUCTION. 
 
 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 
 induction. 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 
 
 * Reid, Intellectual Powers, essay vii. eh. 3. Campbell, Phil. 
 Rhet. b. i. ch. 5. sect. 2. Gambier, Mor. Evid. ch. 1. Stewart, 
 Elem. Phil, of Mind, vol. i. Introd. 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- 
 suasion, 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 
 substance ; 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 susceptible of magnetical attraction. 
 So, having often noticed, that, by the applica- 
 tion 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 ex- 
 posed to those opposite 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 general 
 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 
 immediate succession, they acquire a tendency 
 mutually to suggest each other ; so that, when 
 either of them occurs to our thoughts, the other 
 readily follows it. We learn also from ex- 
 perience, that the durability of past impressions 
 on the mind depends greatly on the attention, 
 with 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 
 individuals of different classes, we discover 
 important resemblances between one species 
 and another, and are enabled to obtain more 
 extensive 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 
 several 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 after 
 truth. We employ it not only in the investi- 
 gation of general truths, relating to things in 
 actual existence ; but in gaining those practi- 
 cal rules and maxims, by which the common 
 business 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 INDUCTION. 
 
 " fence, where the word occurs, affords, 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 
 " imperceptibly enter into the abstract and com- 
 " plex notions, annexed to numberless words in 
 " their mother tongue, of which we should find 
 " it difficult, or impossible, to convey the sense 
 " by formal definitions."* 
 
 100. In another place, Mr. Stewart has 
 described 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, essay v. ch. 1. 
 
INDUCTION. 81 
 
 u 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 
 k - which are merely accidental accessories or 
 1 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 
 " cases, agreeing in some circumstances, but 
 " differing in others, and all attended with the 
 "same result, a philosopher connects, as a 
 "general law of nature, the event with its 
 "physical cause, he is said to proceed according 
 " to the method of induction."* 
 
 • Elements of the Philosophy of the Mind, vol. ii. eh. 4. sect. 1. 
 
82 INDUCTION. 
 
 101. Inductive conclusions will amount to 
 moral certainty, whenever our experience has 
 been uniform, and the number of cases examin- 
 ed sufficiently numerous. But this reasoning 
 is liable to be fallacious through impatience 
 in the investigation, by which judgments are 
 hastily formed, without a sufficient accumu- 
 lation of facts. The number of instances, 
 required 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 
 fortis has been known to dissolve silver in one 
 instance, 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 
 favourable and unfavourable instances leaves 
 the mind in a state of suspense, 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 
 respects to analytical induction. They both 
 proceed on the same general principle, that 
 nature is consistent and uniform in her opera- 
 tions ; so that from similar circumstances similar 
 effects 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 vagueness. 
 Sometimes it denotes only a slight and distant 
 
 * Bacon, Novum Organum, lib. i. Campbell, Phil. Rhet. vol. i 
 cli. 5. sect 2. Beattic, Essay on Truth, part i. ch. 2. sect. G. 
 Tatham, Chart and Scale of Truth, vol. i. ch. 4. sect. 1. Stewart, 
 Elem. vol. ii. ch. 4. Gambier, Mor. Evidence, ch. 2. Scott, Intel- 
 Phil. Appendix, ch. 2. 
 
84 ANALOGY. 
 
 resemblance ; as that, which is found between 
 different species of the same genus. Some- 
 times it implies a correspondence of different 
 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 are 
 so similar in their nature, that it is not easy 
 to point out their specifick difference. Every 
 inductive process commences with analogy. 
 The following circumstances appear to mark 
 a distinction between them, sufficient to justify 
 their being treated as separate articles. First, 
 induction is a process from several individuals of 
 a class to the whole ~ts conclusions therefore 
 are always general. But by analogy we argue 
 from one individual being to another of the 
 same class ; and from one species to another. 
 Secondly, the evidence, employed in analogy, 
 is wholly indirect and collateral ; — the coexist- 
 ence of two qualities 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 individ- 
 

 ANALOGY. 
 
 85 
 
 uals of that class. It is true, that in all induc- 
 tion analogy must be used ; for we can never 
 separately examine every individual of a whole 
 class, however cautiously we may proceed. 
 So far as we extend our observations or 
 experiments, the evidence is direct ; but, with 
 
 ;ird to the remaining subjects of the class, 
 the conclusions must rest wholly on analogy. 
 
 105. Analogy is an unsafe ground of reason- 
 in"- : and its conclusions should seldom be 
 received, without some degree of distrust. 
 When thing:- 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 
 information, which might thence have been 
 derived, from those quadrupeds, whose internal 
 structure was thought to approach nearest to 
 that of the human body. In this way 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, 
 8 
 
86 ANALOGY. 
 
 • 4 which we inhabit, and the other planets, 
 " Saturn, 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 
 " earth, 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 earth, be the habitation of various 
 " orders 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 earth, than the planets 
 have. 
 
 107. There are many subjects, both specu- 
 lative and practical, about which analogy is 
 
 • Essays on Intellectual Powers, essay i. ch. 4. 
 
AiNALOGY. 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 knowl- 
 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, 
 " adjustment, and reconciliation of them with 
 "one another, that the sagacity and wisdom 
 " of the court are seen and exercised."* 
 
 103. 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- 
 
 * Taley, Polit. Phil. 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 assists 
 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 of facts. 
 These are for the most part so unconnected 
 and independent, so transient in their exist- 
 ence, 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. ch. 16. Campbell, 
 Phil. Rhet. 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, Elera. Phil. Mind, vol. ii. ch. 4. sect. 4. Gambier, 
 Moral Evidence, ch. 2. 
 
REASONING ON FACTS. 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 of communities. 
 
 110. Facts maybe 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. 
 
 First, 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 
 usually speak as they think. Xo effort of 
 invention is required to relate things as they 
 are ; but arts of deception require study ; and 
 arc seldom practised, but for criminal purposes. 
 The moral sense is rarely, if ever, depraved 
 8* 
 
90 REASONING ON FACTS. 
 
 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 ten- 
 dency to veracity. Children at first believe 
 every 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 one, who had sensible 
 evidence of the fact asserted. This is the only 
 testimony of this kind, in which we can have 
 full confidence ; and, when accompanied by 
 circumstances of the most favourable nature, 
 produces a firm belief ; even though it be the 
 declaration 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 
 probabilities, resulting from the separate testi- 
 monies 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- 
 lore, concert be excluded, there remains no 
 other cause for the concurrence, than the ex- 
 istence of the fact. 
 
 114. That evidence, which is professedly 
 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 applied 
 as evidence on a subject in no way connected 
 with that, on which it was originally introduc- 
 ed. This is termed incidental testimony, and 
 it is usually considered of greater validity than 
 that, which is direct ; because, from the manner 
 in which it was introduced, there is less reason 
 
 
92 REASOMNG 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 
 passed from the original witness to him. 
 
 116. The circumstances, constituting what is 
 called the 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 
 
REASONING OH 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 absolutely inconsistent with any intention to 
 deceive or prevaricate, as well as with a con- 
 scions 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 
 human 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 contemplate 
 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 
 occur, this testimony is secure against any 
 
94 REASONING 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 
 forgotten, 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 is fugitive in its na- 
 ture, and the existence of the original witness 
 must be determined by the testimony of a sec- 
 ond witness, whose existence must be admitted, 
 in like manner, on the credibility of a third, 
 and so on. Besides, the care, which copying 
 requires, gives a copy a preference to transmit- 
 ted oral testimony. Mistake, in the former, is 
 much 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 
 
REASONING ON FACTS. 95 
 
 probable, that the different copies would sub- 
 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 belief, 
 extending both to specifick facts and general 
 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 
 
96 REASONING ON FACTS. 
 
 things must be received on trust. Most men 
 can give no better reason for their belief of 
 the greater 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 
 assertions were true, their falsehood would 
 have been detected ; and partly on experience ; 
 for, though we are in the constant practice of 
 admitting 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 cor- 
 rected. In these, therefore, propositions uni- 
 versally 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 the 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 
 
 
REASONING ON FACTS. 97 
 
 have been observed only by a few persons ; or 
 to things, supposed to have happened in re- 
 mote antiquity, or in fabulous ages. G< neral 
 notoriety or universal belief, with regard to 
 such propositions, is not a sufficient ground of 
 assent. 
 
 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 satisfactorily 
 accounted for in any way, but by admitting 
 the event in question. 
 
 125. Belief, grounded on circumstantial evi- 
 dence, is usually denominated presumption ; 
 and presumptions are either slight or violent, 
 according 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- 
 
 9 
 
98 REASONING ON FACTS. 
 
 writing resembles his, is only slight ; for one 
 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 circumstance must be 
 such, not only as would 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 
 island, 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 
 necessary consequence of a person's having 
 resided 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 what reason would lead us to expect. 
 This analogy is denominated internal evidence. 
 Facts, which are rendered probable by inter- 
 
REASONING ON FACTS. 99 
 
 nal evidence, may have their probability in- 
 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 frozen 
 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, ot 
 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 cqiiicasnal, by reason of the irregularity 
 of their appearance, belong exclusively to the 
 province of testimony ; as, whether a ship sailed 
 on Tuesday or on Friday ; whether a man made 
 his will, or died intestate. The probability, 
 
 I 
 
100 REASONING ON FACTS. 
 
 that any asserted fact of this sort happened at 
 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 one, 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 improbabil- 
 ity of such facts must be overcome by an in- 
 creased weight of testimony. 
 
 130. Those facts or events, which are admit- 
 ted with the greatest difficulty of all, are such 
 as are supernatural, or miraculous. These, 
 contradicting our invariable experience, and 
 opposing the well known laws of corporeal 
 nature, are in themselves in the highest degree 
 improbable ; and require for their belief a 
 testimony so ample, and attended by such 
 circumstances, as would render its falsehood 
 no less miraculous than the fact attested.* 
 
 * (Gilbert, Law of Evidence. Kirwan, Logick, part iii. ch. C. 
 Locke, Essay on the Understanding, b. iv. ch. 16. Gambier, Moral 
 Evidence, ch. 2. 
 
 s- 
 
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 ade- 
 quate cause. When we speak of events as 
 happening fortuitously, or by chance, 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 manifest, that there are so many 
 chances of those events ; and that no one of 
 them is more probable than the rest. 
 
 132. The doctrine of chances is that, which 
 teaches the degree of probability or improbabil- 
 ity of any one of a given number of events, con- 
 sidered as equally possible. Thus, on throwing 
 a die, it is certain that some one of its six faces 
 will be turned up ; but, 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 I of a certainty. Hence the general rule 
 
 9* 
 
102 CALCULATION Ok 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 fa- 
 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 t will ex- 
 press the probability of its happening, and the 
 fraction t, 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 will be just equal 
 to their common denominator. And as in 
 every case it is certain, that an event will 
 either happen 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 event, has a determinate value before the 
 
CALCULATION OF CH V-NCE3. 103 
 
 event takes place. The value*$|C#j&r€>;}H < ia 
 tion is in all cases estimated by multiplying 
 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 independent, when 
 they have no connexion with 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 a joint event on two 
 dice, though each is independent of the other, 
 singly considered, is affected by all the possibil- 
 ities of failure in each of the conjoined events. 
 Now there are thirty-six possible events on 
 two dice considered conjointly ; for each has 
 six faces, and each face of the one may be com- 
 bined with each face of the other. Therefore 
 the possible appearances are 6 X 6 = 36. But, 
 of these combinations, there is but one pro- 
 
104 CALCULATION OF CHANCES. 
 
 ductive 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 A. 
 
 136. Hence the probability of two or more 
 independent but joint events is equal to the 
 product of the chances of each. Thus, the 
 probability of throwing three aces successively 
 on one die is £ X i X i = *£?. So if the proba- 
 bility, that one man, A, will live a year, be A, 
 and the probability of the life of another man, 
 B, for one year, be A, the probability, that 
 both will live another year, is but t<t X t s <j = 
 rcnr. Hence the concurrence of two events is 
 less probable than the occurrence of either ; 
 and is even improbable, though each is prob- 
 able and completely independent of the other. 
 
 137. From the foregoing rule it is manifest, 
 that the joint occurrence of two or more equi- 
 casual, independent events is improbable ; and 
 the more so, the more numerous they are. For 
 the probability of each is £ ; therefore the joint 
 chance of two such events is ^ X 1 = I ; and of 
 three such events is i X i X i=$. So the con- 
 currence of two independent, improbable facts 
 is still more improbable. For, supposing the 
 
CALCULATION OF CHANCES. 105 
 
 improbability of one of them to be *, and that 
 of the other i, their joint improbability would 
 
 be a\r. By the same rule, the improbability 
 of the death of A within a year being Ar 5 and 
 that of the death of B within a year t<t, the im 
 '>:il>ilitv, that both will die within a year, 
 — xSu. And 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 ft X rj = t\&. And the probability, that 
 B will live and that A will die, is t<j X T 4 o = 
 
 138. A dependent event is one, whose exist- 
 < nee is rendered more or less probable by the 
 chances 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 ; 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 tV But the chance of doing this on 
 the second trial will be different ; for, as one 
 of the balls has been taken out, there are but 
 eleven remaining ; and since, in order to the 
 second trial, 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 w T hite 
 ball at the second trial will be only A ; and 
 the chance of drawing it the first and second 
 time will be & = fX t 5 t = ?¥. The separate 
 probability of drawing out a white ball at a 
 third trial, since two white balls have been 
 removed, will be tV ; and the chance of draw- 
 ing three white ones at three successive trials 
 will be i X tV X tV = Mr = +- 
 
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 
 calamities. Now, as the chance of his having 
 survived 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 & = £ • 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 §• Hence 
 the probability of his having lived through 
 both dangers is IX|= & = £• Therefore it 
 is merely doubtful whether he survived both 
 calamities. If only i of the crew survived the 
 
108 DEMONSTRATIVE REASONING. 
 
 second danger, then his escape would be im- 
 probable ; for f- X i = T V If only two out of 
 the twelve ships were lost, and consequently 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 
 t§ X § = U = I ; a slight probability.* 
 
 CHAPTER SEVENTH. 
 
 GENERAL DESCRIPTION OF DEMONSTRATIVE REASONING. 
 
 142. The general nature of demonstrative 
 reasoning 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 Chances, Introduction. Kirwan, Logick. 
 part ill. ch. 7. 
 
DEMONSTRATIVE REASONING. 109 
 
 gent, and perpetually varying. Our reasoning 
 on these must be grounded on the observation 
 of our senses ; and the conclusions, which 
 we make, are liable to be uncertain. But 
 demonstrative 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 cer- 
 tainty. 
 
 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 
 obvious. 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 DEMONSTRATIVE 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 
 employed 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 
 Understanding :* "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 
 "only way whereby the precise meaning of 
 " moral words can be known ; and yet a way, 
 " whereby their meaning may be known cer- 
 " tainly, and without leaving any room for 
 " contest." In another placet he says, " the 
 "relation of other modes may certainly be 
 " perceived, as well as those of number and 
 
 * Book iii. ch. 11. sect. 16. 
 t Book iv. ch. 3. sect. 18. 
 
DEMONSTRATIVE REASONING. Ill 
 
 44 extension ; and I cannot see why they should 
 " not also be capable of demonstration, if due 
 11 methods were thought on to examine or pur- 
 14 sue their agreement or disagreement." 
 
 145. Dr. Rcid distinguishes demonstrative 
 reasoning into two kinds, which are metaphy- 
 sical and mathematical. " In metaphysical 
 44 reasoning," he observes, 44 the process is 
 44 always short. The conclusion is but a step 
 44 or two, seldom more, from the first principle 
 44 or axiom, on which it is grounded ; and the 
 44 different conclusions depend not one upon 
 44 another. It is otherwise in mathematical 
 44 reasoning. Here the field has no limits. One 
 44 proposition leads to another; that to a third, 
 44 and so on without end. If it should be asked, 
 44 why demonstrative reasoning has so wide 
 " a field in mathematicks, while, in other 
 " abstract subjects, it is confined within very 
 44 narrow limits ; I conceive this chiefly owing 
 44 to the nature of quantity, the object of math- 
 44 ematicks."* 
 
 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 vii. ch. 1. 
 
112 DEMONSTRATIVE REASONING. 
 
 science. Wherever the subjects of our reason- 
 ing are independent on the existence of thmgs, 
 and are of a nature to afford exact definitions 
 and general propositions of undoubted certain- 
 ty, there this method of reasoning may be 
 employed. And it appears unnecessary to 
 concede, that these elements of demonstration 
 are no where to be found, except in the sci- 
 ence of mathematicks. 
 
 147. Professor Scott, speaking of Dr. Reid's 
 division of demonstrative reasoning, 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 advanc- 
 " 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 occasional- 
 " ly assume the demonstrative form. The ex- 
 " istence of a Deity, the immateriality of the 
 
DISTINCTIONS OF REASONING. 113 
 
 1 human soul, and other moral or metaphysical 
 
 * truths, have perhaps been as fairly demon- 
 ' stratcd as the Pythagorean proposition, or 
 1 the parabolick motion of projectiles. But 
 ' some sciences are much more susceptible of 
 i this kind of proof than others ; physicks 
 ' admitting 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 
 4 manner of proof so accurate and legitimate, 
 ' that it may fairly be called a completely de- 
 ' monstrative science, and the only one, which 
 1 is justly entitled to that name."* 
 
 CHAPTER EIGHTH. 
 
 DISTINCTIONS OF REASONING. 
 
 148. Reasoning is further distinguished 
 into 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 Tntell. Phil. chap. 8. sect. 4. 
 
 10* 
 
114 DISTINCTIONS OF REASONING. 
 
 mathematicks afford numerous instances of 
 conclusions 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 
 within twelve days of each other, from our 
 knowledge of the causes, which occasion those 
 phenomena. 
 
 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 
 lunar eclipse ; and we infer the being of a God 
 from our own existence and that of the objects 
 around us. All reasoning concerning the 
 properties and laws, both of mind and body, 
 proceeds on this principle. It is only by a 
 careful observation of facts, that the laws, 
 which regulate them, can be discovered. 
 
 150. Another distinction of reasoning is 
 into direct and indirect. The reasoning is di- 
 rect, when the proofs are so applied, as to show 
 immediately the agreement or repugnancy between 
 the subject and predicate of the proposition in 
 
DISTINCTIONS OF REASONING. 115 
 
 question. In indirect reasoning, the argu- 
 ments, which we employ, are not intended pri- 
 marily to show the relation between the terms 
 of the proposition, whose truth we would 
 establish ; 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 
 original proposition. The former course is 
 usually called a proof per impossibile ; and the 
 latter, a reductio ad absurdum. 
 
 151. Mathematicians make frequent use of 
 indirect reasoning. Thus, Euclid proves, by 
 an indirect course, that, "if two circles touch 
 " each other internally, they cannot hare 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 : and thence 
 
116 SYLLOGIST1CK REASONING. 
 
 infers the truth of the proposition, which he 
 first asserted. So moralists prove the exist- 
 ence of an all-wise and powerful Creator, by 
 tracing the absurdities, which the contrary 
 supposition involves. 
 
 152. Another form of indirect reasoning, 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 death, this retribution is due 
 a fortiori to the wretch, who has committed 
 parricide. 
 
 CHAPTER NINTH. 
 
 GENERAL DESCRIPTION OF SYLLOGISTICK REASONING. 
 
 153. All reasoning proceeds by comparison ; 
 and two comparisons are necessary to enable 
 us to make a conclusion. The subject and 
 predicate of the proposition to be proved must 
 be separately compared with some third term, 
 or common measure ; and from these compari- 
 sons we infer their agreement or repugnancy, 
 
SYLLOGISTICK REASONING. 117 
 
 This process, when expressed in words, con- 
 of three propositions, and has been termed 
 syllogism* 
 
 154. Syllogism was regarded, for many cen- 
 turies, 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 in- 
 dustry of Aristotle, who traced and analyzed 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 that philosopher, the name syllogism has 
 usually been employed to denote an argument, 
 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 affirmed of any genus 
 may be affirmed of all the species included un- 
 der it. 
 
 * TvWoyiopbs, compiiiaiio, a (7vXAoy<£o/iai, colligo, ratiocinor, compido. 
 
118 SYLLOGISTICK REASONING. 
 
 155. Syllogism and induction proceed in 
 opposite 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, predicating 
 the genus of the species, and the species of 
 the individual. 
 
 156. The difference ol 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 men 
 rarely live to the age of a 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, re- 
 versed in syllogistick language, would run thus, 
 
SYLL0G1STICK 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 may also be used with success in 
 exposing the weakness of arguments, stated in 
 loose or figurative language. But it is of no 
 service in helping us to the discovery of new 
 truths. We must know a thing first, Mr. 
 Locke observes,* and then we can prove it 
 syllogistically. 
 
 158. As syllogism operates wholly on gen- 
 eral propositions, and definitions previously 
 established, 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 words ; 
 " and words are the marks of ideas. If there- 
 " fore ideas themselves, whichmake the ground- 
 "work of our reasonings, are confused, and 
 
 * Essay, 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 RECULAR 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 projwsitions, the last of which is deduced 
 from the two preceding, and is substantially con- 
 tained 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- 
 
 * " Sy llogusn: tfs ex propositionibus constat ; propositiones, ex 
 " verbis ; verba notionum tesserae sunt. Itaque si notiones ipsae, 
 " id quod basis rei est, confusae sint, et temere a rebus abstractse, 
 ,{ nihil in iis, quae superstruuntur, est firmitudinis. Itaque spes est 
 u una in inductione vera." Novum Organum, lib. i. aph. 14. 
 
■ ri.AR BY] 121 
 
 tion. A third term, h mon relation 
 
 them both, Lb invenl lied to them 
 
 successively, in two distinct p ritions. 
 
 These are called • from, th- 
 
 tlif proposed (p.; ia interred, as a conclu- 
 
 : : and its subject and predicate bj bei 
 
 parated, according a.- they w< 
 
 ad in the pi to agree, or nut. with 
 
 the term introduced. It is obvious, that, if 
 
 with a third, they must 
 each and that two things, of 
 
 i chick i the other disagrees, with 
 
 a third. > with each other. The 
 
 former of these rules is the foundation of all 
 affirmative conclusions, and the latter of all 
 negati 
 
 161. The names of the three propositions 
 are the . the minor, and the conclusion. 
 
 These ar of three terms, denomin- 
 
 ated the major, the minor, and the middlt 
 Th .///• ■// the ma- 
 
 joi I . because it is the most general : and 
 the s m the minor term. 
 
 because it is the least general. These two are 
 also denominated the extreme* : and the third 
 
 * See note B. at the end of the book. 
 11 
 
122 REGULAR SYLLOGISMS. 
 
 term, introduced as a common measure be- 
 tween them, 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 
 general, 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 terms the minor premise ; and 
 the two extremes, connected by a copula, make 
 ap 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 con- 
 clusion may be either universal affirmative, 
 universal negative, particular affirmative, or 
 particular negative. 
 
 163. In every regular syllogism, the major 
 proposition is placed first ; the minor next ,* 
 
 * See note C, at the end of the book. 
 
REGULAR SYLLOGISMS. 123 
 
 ;ind the conclusion last ; as in the following 
 example. 
 
 Every vegetable is combustible; 
 
 Every 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 truth, 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 REGULAR SYLLOGISMS. 
 
 tree is combustible ; for it is a primary law of 
 syllogistick reasoning, that whatever may be 
 affirmed of any general term, may be affirmed 
 of every species and individual included within 
 its extension. 
 
 165. In the regular syllogism, each step of 
 (he reasoning process is distinctly expressed ; 
 but, in familiar language, one part is frequent- 
 ly omitted, which may be readily found by 
 examining 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 
 human invention. But there is a latent prop- 
 osition, 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 stand thus ; 
 
 No language is perfect ; 
 Because it is a human invention ; 
 And no human invention is perfect. 
 
 This is the regular syllogism reversed ; which, 
 rectified, will stand thus ; 
 
REGULAR SYLLOGISMS. 125 
 
 No human invention i p ufect; 
 Every language is a human invention; 
 
 Therefore no language is perfect. 
 
 166. Every assertion, accompanied by a 
 reason why it is made, contains the elements 
 of a 'gism, namely, the major, minor, and 
 middle terms. Every such assertion, made in 
 the familiar form of language, may he 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 proposition, without the reason, 
 before annexed to it, will constitute the con- 
 clusion of the syllogism. 
 
 167. For example, Dr. Johnson says of en- 
 vy, " It is, above all other vices, inconsistent 
 " with 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, inconsist- 
 ent 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 whatever, that which, 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 ; , 
 
 Envy 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 manner may the simple elements of 
 reasoning, 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 proposition, 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, w T e 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 
 agreement or repugnancy, which was before 
 
128 REGULAR SYLLOGISMS. 
 
 admitted between the middle and major terms, 
 ist be also admitted between the major and 
 ior terms. 
 
 170. Any regular syllogism may be reduced 
 liliar form of reasoning, by the follow - 
 : First, state the conclusion, omitt 
 illative therefore; then, subjoin the middle 
 i together with the minor, or some pronoun 
 as its substitute, preceded by some causal par- 
 is .since, for, or because. For example. 
 
 Every animal, possessing wings and feathers, is a bird ; 
 An ostrich is an animal, possessing wings and feathers, 
 
 ;>_' 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, de- 
 serves the detestation of mankind ; 
 Tyrants disregard the rights of their fellow beings ; 
 Therefore tyrants deserve the detestation of mankind. 
 
 • 
 
REGUL kB SI LLOGISM8. 129 
 
 II. 
 Th«_-\\ vrho subvert the foundations of morality and 
 
 religion, ou^ht not to be r 1 ; 
 
 foundations of morality and religion ; 
 Therefore ;•' bt not to be respect 
 
 III. 
 
 . which can live in more elements than 
 one, is an 
 Some animals can live in more elements than one; 
 Therefore some animals are amphibio 
 
 IV. 
 
 !ute habits can be a safe companion ; 
 roved minds are dissolute in their 
 habi'- ; 
 Therefore some persons of improved miuds are not safe 
 companio; 
 
 The conclusion of the first syllogism is a 
 universal affirmative proposition ; that of the 
 b e c ond, a _ . * i v e ; t h a t of t h e t b i r d . 
 
 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.* 
 
 • Comrarn systems of Logick. Coliard. Logick. part i.-. ch. 4 
 
;.>0 IRREGULAR SYLLOGISMS. 
 
 CHAPTER ELEVENTH. 
 
 ENTIIYMEMES. 
 
 172. Besides the regular, categorical syllo- 
 gism, described in the preceding chapter, there 
 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 de- 
 fective syllogism, consisting of the conclusion 
 and only one of the premises ; the other being 
 suppressed, as too obvious to need insertion. 
 It is of very general use, both in writing and 
 conversation. 
 
 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, 
 containing the reason, the major premise is 
 omitted ; if the predicate of the conclusion be 
 expressed, 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 
 
 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. Enthvmemcs may be expressed in 
 various ways, and have sometimes been dis- 
 tinguished 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 astray from reason. 
 
132 IRREGULAR SYLLOGISMS. 
 
 They, who deny a future state of retribution, are in 
 error ; 
 
 For they deny the doctrine of the Bible. 
 
 175. Although the conclusion be placed 
 after 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 man above the 
 " rest of sensible beings, and gives him all the ad- 
 " vantage and dominion, which he has over them ; 
 
 " It is certainly a subject, even for its nobleness, worth 
 " our labour to inquire into."* 
 
 Each of these enthymemes contains the ele- 
 ments of a syllogism, namely, the major, minor, 
 and middle terms ; which may be easily dis- 
 tinguished. 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 ; 
 If it be a violation of the 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 
 absolute 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 reasoning, 
 since in each the elements of a perfect syllo- 
 gism are expressed.* 
 
 * Collard, Logick, part. iv. ch. 6. 
 
 12 
 
134 IRREGULAR SYLLOGISMS. 
 
 CHAPTER TWELFTH. 
 
 CONDITIONAL AND DISJUNCTIVE SYLLOGISMS. 
 
 178. A 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 first 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 
 require the truth of the consequent. By the 
 same necessity it will follow, that, if the conse- 
 
IRREGULAR SYLLOGISMS. 135 
 
 quent 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. 
 
 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. A 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 
 
COMPOUND SYLLOGISMS. 137 
 
 reason, since it is nothing more than a formal 
 and circuitous method of stating a fact. 
 
 BHAPTER THIRTEENTH. 
 
 COMPOUND . J LLOGISHS. 
 
 181. A compound syllogism consists of more 
 than three propositions, and may be 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 
 
 unjust ; for they require people to abandon their 
 
 dearest concerns ; 
 Therefore laws, which restrain the freedom of conscience, 
 
 endanger the stability of government. 
 
 The major and minor premises, with their 
 respective proofs, form two enthymemes, which 
 may readily be reduced to regular syllogisms. 
 Discard these proofs, and a regular syllogism 
 will remain. 
 12* 
 
I 03 COMPOUND SYLLOGISMS. 
 
 182. The epiclnrcma is much used in con- 
 versation, publick harangues, and oratorical 
 discourses. Cicero's defence of Milo is an 
 argument 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 con- 
 clusion, namely, that it was lawful for Milo to 
 kill Clodius. 
 
 1 83. The Dilemma* is a compound argument, 
 ivhich establishes a general conclusion, either 
 directly by proving its necessity, or indirectly 
 by showing the impossibility or absurdity of its 
 contrary, in every supposable 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. 
 
 * Ah, bis, and Xa/*/?dvw, capio. 
 
COMPOUND SYLLOGISMS. 139 
 
 The subject of the conclusion is first divided 
 into two classes, namely, those magistrates, 
 who do, and those who do not execute the 
 laws. The attribute, hatred, is then affirmed 
 of each class separately, and is finally predi- 
 cated of the whole subject. This dilemma 
 may be resolved into three regular syllogisms. 
 The major premise and the conclusion, taken 
 together, constitute a regular enthymeme ; and 
 the four intervening propositions form two 
 enthymemes, hypothetically stated. 
 
 184. Pyrrho, the ancient sceptick, asserted, 
 that no one can have certain knowledge of any 
 thing. One of his friends reproved him in the 
 following dilemma : 
 
 You either know what you say to be true, or you do not 
 
 know it; 
 If you do know it to be true, that very knowledge proves 
 
 your assertion to be false, and you do wrong to make 
 
 it; 
 
 If you do not know it to be true, you do wrong to assert 
 it, since no one has a right to assert what he does not 
 know to be true ; 
 
 Therefore, in either case, you do wrong to assert, that no 
 one can have certain knowledge of any thing. 
 
 185. A dilemma is a form of argument 
 frequently employed both in moral and math- 
 
140 COMPOUND SYLLOGISMS. 
 
 ematical reasoning. The geometrician adopts 
 this method, when, in order to prove the 
 equality of two lines or angles, he first assumes, 
 that, if they are not equal, one must be either 
 greater or less than the other ; and, having 
 removed both these suppositions, he thence in- 
 fers, that the proposed lines or angles are equal. 
 186. In order to understand fully the prin- 
 ciple of reasoning in a dilemma, it is necessary 
 to consider the major premise as conditional, 
 the first part of which is commonly omitted, to 
 wit, the antecedent, which consists of a general 
 assertion, conditionally made, which it is the 
 object of the dilemma to disprove. What 
 usually appears as the major premise, is only 
 the consequent of this member, consisting of an 
 enumeration of all the suppositions, of which 
 the subject will admit.* If then all these sup- 
 positions be rejected in the minor premise, the 
 antecedent will of necessity be rejected in the 
 conclusion. This reasoning proceeds univer- 
 
 * By supplying the antecedent in the example first 
 stated, the major premise will stand thus : 
 
 If all magistrates be not exposed to the hatred of their fellow 
 men, it is either because they execute the laws, or suffer them to be 
 violated. 
 
COMrOUND SYLLOGISMS. 141 
 
 sally from the removal of the consequent to 
 the removal of the antecedent. 
 
 187. A dilemma may be defective in two 
 ways ; first, when the conditions are not ac- 
 curately stated in the major premise; secondly, 
 when the argument may he retorted with equal 
 force on him, who offers it. A remarkable 
 instance of the retort of a dilemma happened 
 in the singular controversy between Protagoras 
 and Euathlus. The former engaged to teach 
 the latter the art of pleading for a stipulated 
 reward, one moiety of which was to be paid 
 in band, and the other when the pupil gained 
 his first cause at court. After a short time 
 Protagoras sued Euathlus for the remaining 
 moiety of the money, and made use of this 
 dilemma : 
 
 The case must be decided either in my favour or in 
 
 yours ; 
 If it is decided in my favour, the sum will be due to me 
 
 according to the sentence of the judge ; 
 If it is decided in your favour, it will be due to me by 
 
 virtue of our contract ; 
 Therefore, whether I gain or lose the cause, I shall obtain 
 
 the reward. 
 
 Euathlus thus retorted the dilemma. 
 
142 COMPOUND SYLLOGISMS. 
 
 I shall either gain the cause, or lose it ; 
 
 If I gain the cause, nothing will be due to you according 
 
 to the sentence of the judge ; 
 If I lose the cause, nothing will be due to you according 
 
 to our contract ; 
 Therefore in neither case shall I pay you the reward. 
 
 Sometimes the consequent of the major consists 
 of more than two parts, and then the syllogism 
 is called a trilemma, tesseralemma, and so on. 
 
 188. The Sorites* is an irregular, compound 
 argument, consisting of a series of propositions, 
 arranged in such a manner, that the predicate 
 of each preceding proposition forms the subject 
 of that which follows ; and the concluding prop- 
 osition unites its predicate to the subject of the 
 first. Thus, 
 
 Avaricious men have many desires ; 
 
 They, who have many desires, are in want of many things ; 
 They, who are in want of many things, are unhappy ; 
 Therefore avaricious men are unhappy. 
 
 This example contains the substance of two 
 syllogisms, which may be thus stated in regu- 
 lar form : 
 
 I. 
 
 Those, who have many desires, are in want of many things ; 
 
 Avaricious men have many desires ; 
 
 Therefore avaricious men are in want of many things. 
 
 * 7.u>p&$, c&ngeries, acerims. 
 
COMPOUND SYLLOGISMS. 
 
 II. 
 
 Those, who want many things, are unhappy ; 
 Avaricious men want many things ; 
 Therefore avaricious men ore unhappy. 
 
 189. Every sprites may be resolved into as 
 many syllogisms as it contains middle terms : 
 or as it has propositions intervening between 
 the first and the last. The second proposition 
 of the sorites forms the major premise of the 
 first syllogism ; the third, the major of the 
 second, and so on. The following example 
 may be reduced to four syllogisms. 
 
 The mind is a thinking substance ; 
 
 A thinking substance is a spirit ; 
 
 A. spirit has no composition of parts ; 
 
 That, which has no composition of parts, is indissoluble ; 
 
 That, which is indissoluble, is immortal ; 
 
 Therefore the mind is immortal. 
 
 190. A sorites may be formed of hypotheti- 
 cal enthymemes, any number of which may be 
 so joined in a series, that the consequent of 
 each shall become the antecedent of the next 
 following ; in which case, by establishing the 
 antecedent of the first, we establish the conse- 
 quent of the last ; or, by removing the conse- 
 quent of the last, we remove the antecedent of 
 
144 SOPHISMS. 
 
 the first. This is manifest in the following 
 example : 
 
 If men are to be punished in another world, God must be 
 
 the punisher ; 
 If God be the punisher, the punishment must be just ; 
 If the punishment be just, the punished must be guilty ; 
 If the punished be guilty, they could have done otherwise ; 
 If they could have done otherwise, they were free agents ; 
 Therefore, if men are liable to punishment in another 
 
 world, they must be free.* 
 
 CHAPTER FOURTEENTH. 
 
 SOPHISMS. 
 
 191. A knowledge of the different kinds of 
 reasoning, with their respective laws and 
 principles, is of important use in enabling us 
 to detect the sophistry and false reasoning 
 employed in the support of error. But the 
 rules of logick are of little service, till habit 
 has rendered them familiar. By frequently 
 examining the judgments and conclusions, 
 which we have formed, and comparing them 
 with those rules of procedure, which lead to 
 certain results, we insensibly acquire the habit 
 
 * Common systems of Logick. Locke, Essay on the Understand- 
 ing, b. iv. ch. 17. 
 
SOPHISMS. 146 
 
 of conducting our intellectual processes with 
 accuracy, and also a facility in detecting the 
 false deductions of others. 
 
 192. Arguments, which contain a latent 
 fallacy under the general appearance of cor- 
 rectness, arc denominated sophisms. They 
 have been distinguished into various kinds, 
 from which the following are selected, as those 
 which are practised with the greatest frequency 
 and success. 
 
 193. First. Ignoreitio Elenchi, a misappre- 
 hension of the cjuestion. This sophism is com- 
 mitted when the arguments employed are of 
 a nature to establish some other point, foreign 
 to the question in debate ; as if a person should 
 attempt to prove, that Alfred the Great was a 
 scholar, by affirming only, that he founded the 
 University of Oxford ; or, that Peter the Her- 
 mit was not a Christian, by proving that he 
 was an ignorant fanatick. Neither of these 
 facts has any necessary connexion with the 
 question to be proved for a man may be 
 a patron of science, without being learned 
 himself ; and an ignorant fanatick may be a 
 believer in Christianity. 
 
 194. Disputants are frequently guilty of this 
 13 
 
1 46 SOPHISMS. 
 
 fallacy, when, in the heat of controversy, they 
 wander insensibly from the precise subject of 
 discussion. It is also sometimes committed 
 by design ; as when a disputant, finding his 
 adversary too powerful, or his position un- 
 tenable, endeavours to gain an advantage by 
 altering the question. The only effectual 
 security against this species of sophistry is, to 
 have the subject accurately defined, and to 
 keep it steadily in view. 
 
 195. Secondly. Petitio Principii, a begging 
 of the question. This consists in offering, as 
 proof of a proposition, the substance of that 
 proposition in other words. Thus a person 
 attempts to prove, that God is eternal, by as- 
 serting that his existence is without beginning 
 and without end. The proof and the question 
 to be proved are substantially the same. This 
 fallacy is often practised in familiar con versa 
 tion. Thus a person asks, why opium induces 
 sleep ? He is answered, because it possesses 
 a soporifick quality ; which is equivalent to 
 saying, that it induces sleep because it indu- 
 ces sleep. So we are told, that the grass 
 grows by means of its vegetative power ; and 
 
SOPHI5M3. 147 
 
 that bodies tend to the centre, by reason of 
 their gravitation. 
 
 196. Thirdly. Arguing in a circle. This is 
 a kind of sophistry nearly related to the pre- 
 ceding ; and consists in making two prop' 
 tions reciprocally prove each other. Thus, the 
 Papists prove the truth of the Scriptures, bv 
 the infallible testimony of the church : and 
 then establish the infallibility of the church, 
 by the authority of the Scriptures. The Ne- 
 cessarians practise this sophistry, when they 
 bring their hypothesis to prove a fact, and 
 then allege the fact, as proof of their hypoth- 
 esis. They first assume, gratuitously, that the 
 mind acts mechanically, like the body : and 
 that it never can act. unless the motive, which 
 causes the action, be greater than any other, 
 then existing in the mind. Any particular vo- 
 lition is then declared to be necessary, because 
 the motive, which produced it. was the strong 
 est then in the mind. But when asked for the 
 proof, that this motive was the strongest, they 
 simply refer us to the volition, which otherv 
 could not have taken place. That is, the 
 volition was necessary, because it was prodoc 
 by the strongest motive ; and the motive must 
 
148 SOPHISMS. 
 
 have been the strongest, because the volition 
 was produced. 
 
 197. Fourthly. Non causa pro causa; or 
 the assignation of a false cause. From an un- 
 willingness to be thought ignorant, people often 
 impose on themselves, and on the credulity of 
 their fellow men, by assigning, as the cause of 
 an event, something, that has no perceivable 
 connexion with it. Among illiterate people-, 
 rare occurrences are sometimes thought to have 
 a connexion, barely on account of their proxim- 
 ity in time or place. Thus, should the ap- 
 pearance of a comet be followed by a famine, 
 pestilence, or any other grievous calamity, 
 many people would consider the comet as the 
 cause of that calamity. So, if a person have 
 committed any flagrant crime, and shortly 
 after meet with some distressing evil, the for- 
 mer is readily believed to have been the cause 
 of the latter. This sophism is practised by all 
 those impostors, who make pretensions to 
 supernatural skill in interpreting enigmatical 
 circumstances, and in presaging future events, 
 from dreams and other omens ; by which means 
 they flatter the superstition and credulity of 
 mankind. 
 
METHOD. 14!* 
 
 198. Fifthly. Another species of sophistry 
 is called fallacia accidrntis. This consists in 
 pronouncing concerning the general nature or 
 properties of a thing, from some accidental 
 circumstances. As when certain amusements 
 are condemned, as universally unlawful, because 
 they are occasionally carried to excess. So 
 religion has been denounced, as an evil to 
 mankind, because it has sometimes been as- 
 sumed as a cover for crimes. If a medicine 
 have operated unfavourably, weak persons are 
 ready to reject it universally ; or, if its good 
 effects have been extraordinary, they are ready 
 to adopt it in all cases whatsoever. This is 
 the great cause of error, the substitution of 
 local, partial, temporary connexions, for uni- 
 versal and unchangeable. The great remedy 
 of error is the extensive observation and com- 
 parison of particulars, or laborious induction ; 
 and this is the true logick. 
 
 CHAPTER FIFTEENTH. 
 
 DISPOSITION OR METHOD. 
 
 199.<iVIethod, in logick, is a proper classic- 
 cation and arrangement, of our thoughts on any 
 13* 
 
150 METHOD. 
 
 subject either to facilitate the discovery of new 
 truths, or to assist us in communicating to oth- 
 ers truths already known ; or, lastly, to enable 
 us to preserve for future use the knowledge, 
 which we have acquired, j The disposition best 
 adapted to the investigation of truth is the 
 analytick method ; which is therefore denomi- 
 nated the method of invention ; and that which 
 is best suited to the communication of knowl- 
 edge, is the synthetick method, which for this 
 reason has been called the method of instruc- 
 tion. In both of these methods, ideas are 
 arranged in such order, as to exhibit their 
 mutual connexions and relations. 
 
 200. Analysis* signifies an operation, by 
 which some process of art is retraced, or some 
 compound subject is reduced to its elementary 
 parts. Synthesis^ implies the act of collecting 
 or putting together. By the first we begin 
 with the whole, and proceed by successive 
 steps to the parts, of which it is composed ; by 
 the last we begin with the parts, or the most 
 general principles, and proceed by combining 
 them in due order to make up the whole. 
 
 * 'AvnXuw, resolvo. t 'Zvvridwi, cenjungo, compono. 
 
METHOD. 151 
 
 301- Analysis and synthesis are terms of 
 frequent use in many sciences, bat they have 
 not invariably the wun< s ification annexed to 
 them. They always, bowev< r. d< i ote r >;v" 
 pro . one beginning when the other I 
 
 lates : and they reciprocally explain < 
 oth> r. Th< sometimes both 
 
 with equal advantage in explaining the 
 thing. Thus, the mechanism of a co 
 plicated machine may be D by either 
 
 method. We may do it analytically, by taking 
 .chine, in its entire state, and separating 
 in the reverse order of their com- 
 bination, carefully explaining each par; - 
 proceed, till we arrive at that, with which the 
 mechanical construction commenced. Or 
 
 • • thetick method, and. begin- 
 
 nio in a state of separation, 
 
 ssively in their former order, 
 till the combination is restored. 
 
 J. .Most of the improvements in the dif- 
 ferent science- and arts have been made by 
 analysis. It is by this method, that thing- have 
 been ranked into classes. A species is formed 
 by analyzing individuals ; and a genu- by an- 
 alyzing species. We practise the same meth- 
 
152 METHOD. 
 
 od in learning to read the language of our 
 country. We first acquaint ourselves with the 
 letters of the alphabet. We next trace out 
 their powers, by observing in what manner they 
 are sounded, as they are variously combined in 
 syllables and words. In this way we at length 
 acquire some general rules, by which we can 
 readily give to each letter its appropriate 
 sound, in any new combination. By the same 
 method we learn a foreign language, and uni- 
 versal grammar ; also the philosophy of mind, 
 anatomy, chemistry, botany, and other branches 
 of natural knowledge. 
 
 203. The synthetick method is not adapted 
 to the investigation of new truths, and is rarely 
 employed for that purpose. It is a process of 
 composition ; and consists in putting together 
 a number of things in a particular manner, so 
 as to accomplish some end proposed. But in 
 order to do this, it is necessary for a person 
 previously to possess the knowledge, which it 
 is the object of the operation to evince. With- 
 out this knowledge, he would have nothing to 
 guide him in the selection or arrangement of the 
 parts ; and would be in the condition of a man. 
 who should undertake to make some very com- 
 
METHOD. 153 
 
 pound medicine, without knowing the ingredi- 
 ents, of which it is composed. By successively 
 mixing substances of different kinds, and in 
 various proportions, directed only hy casual 
 circumstances or mere conjecture, it is possi- 
 ble for him ultimately to succeed ; but this 
 would not be likely to happen, till after 
 much waste of time and many unsuccessful 
 efforts. 
 
 204. The superiority of the analytick over 
 the synthetick method, in the investigation of 
 now truths, is very forcibly shown by Mr. 
 Stewart in the following example : " Suppose 
 •• •• Inwty of a very artificial construction, to be 
 " put into my hands, as an exercise for my 
 " ingenuity ; and that I was required to inves- 
 " tigate a rule, which others, as well as myself, 
 " mi<rht be able to follow in practice, for mak- 
 " in^ knots of the same sort. If I were to 
 -proceed in this attempt according to the 
 " spirit of a geometrical synthesis, I should 
 " have to try, one after another, all the vari- 
 " ous experiments, which my fancy could de- 
 " vise, till I had at last hit upon the particular 
 " knot I was anxious to tie. Such a process, 
 " however, would evidently be so completely 
 
154 METHOD. 
 
 " tentative, and its final success would after all 
 " be so extremely doubtful, that common sense 
 " could not fail to suggest immediately the idea 
 " of tracing the knot through all the various 
 " complications of its progress, by cautiously 
 " undoing or unknitting each successive turn 
 " of the thread, in a retrograde order, from the 
 " last to the first. After gaining this first step, 
 " were all the former complications restored 
 " again, by an inverse repetition of the same 
 " operations, which I had performed in undoing 
 " them, an infallible rule would be obtained for 
 " solving the problem originally proposed."* 
 
 205. Though knowledge is chiefly acquired 
 by the analytick method, it is most convenient- 
 ly conveyed to others by the synthetick. The 
 teacher uses one method, while the pupil 
 practises the other. The synthetick method 
 is the most plain, concise, and regular. It 
 coincides with the order, in which the useful 
 arts are practised, and most of the business 
 of life is transacted. It begins with the most 
 general and obvious principles, and leads the 
 mmd directly from known truths to those 
 which are unknown. Instruction in every 
 
 ■» Elom. of the Phil, of the Mind, vol. ii. ch- 4. sect. 3. 
 
METHOD. 
 
 156 
 
 science is given synthetically. It consists in 
 prescribing rules more or less general ; and 
 these rules are nothing more than the results 
 of analytical processes previously performed. 
 
 206. The other purpose of method is to 
 secure to the mind a command over the knowl- 
 edge it has acquired. Memory includes the 
 power of treasuring up and preserving ideas ; 
 and also that of recalling them, when we have 
 occasions for applying them to use. The lat- 
 ter power is usually termed recollection. In 
 respect of both these faculties, the burden of 
 memory is diminished by arranging the sub- 
 jects of our knowledge under distinct heads, 
 and charging the memory with some leading 
 objects, only, in each class. But the same form 
 of arrangement will not equally contribute to 
 render the memory retentive and ready * For 
 this reason, no plan can be prescribed, w T hich 
 will be equally beneficial to all. 
 
 207. People, engaged in the active business 
 of life, are under the necessity of carrying in 
 their minds a multitude of particulars, which 
 are of no further use, than to assist them in the 
 daily business of their calling. To such per- 
 
 * Stewart, Elem. vol. i. ch. 6. sect. 2. 
 
156 METHOD. 
 
 sons a prompt recollection is of the highest im- 
 portance, as it contributes to the despatch of 
 business. They will therefore seek an ar- 
 rangement, with reference to this object ; and 
 the surest method of effecting it is an arbitrary 
 one, suggested by the circumstances of their 
 situation, all which are of a local and tempo- 
 rary nature. While they continue their ha- 
 bitual pursuits, their thoughts will be succes- 
 sively called up by the objects offered to their 
 senses ; but on changing their situation, so as 
 to lose their familiarity with those objects, the 
 ideas, which were associated with them, must 
 in a short time be irretrievably lost. 
 
 208. A different method of arrangement is 
 necessary, to give the mind a durable posses- 
 sion of the acquisitions it has made. The 
 only arrangement, capable of effecting this 
 purpose, is that, which refers the truths, we are 
 solicitous to preserve, to the general principles, 
 with which they are connected. By having 
 our ideas distributed according to this method, 
 reason can lend its aid to the powers of memo- 
 ry, by tracing the natural relations and con- 
 nexions of things, and thus deducing one truth 
 from another. Some sort of arrangement or 
 
RULES OF CONTROVERSY. 157 
 
 other is indispensable to persons of every con- 
 dition ; otherwise but a small proportion of 
 the thoughts, which pass through the mind, 
 could by any effort be recalled. 
 
 CHAPTER SIXTEENTH. 
 
 RULES OF CONTROVERSY. 
 
 209. From the limited extent of human 
 knowledge, and the different points of view, in 
 which the same subjects may be contemplated 
 by different minds, it follows of necessity, that 
 a diversity of opinions must be entertained on 
 many subjects of speculation. In whatever 
 manner people are first led to form their opin- 
 ions, they are usually disposed to defend them 
 afterwards with zeal and pertinacity. Hence 
 arise controversies and disputes, which are 
 oftentimes conducted with such intemperate 
 and misguided zeal, as to inflame animosities, 
 by which the comfort and harmony of society 
 are impaired. 
 
 210. These are the worst fruits of contro- 
 versy. They are, however, merely incidental 
 effects ; and are counterbalanced by others of 
 an opposite character, and of high importance 
 
 14 
 
158 RULES OF CONTROVERSY. 
 
 to the interests of truth and virtue. The 
 advantages of controversy consist in having 
 questions of difficulty and moment settled in a 
 satisfactory manner. The principles of gov- 
 ernment and law have been immovably fixed 
 by the debates, which have passed in deliber- 
 ative assemblies and in courts of justice. 
 
 211. All questions, not susceptible of rigor- 
 ous demonstration, can be correctly settled 
 only by a full and impartial comparison of the 
 reasons on both sides. This is seldom done, 
 with sufficient exactness, by the solitary inves- 
 tigation of an individual. Men rarely enter 
 on the examination of a question wholly free 
 from the bias of a previous opinion respecting 
 it, which makes them more solicitous to find 
 arguments for one side than for the other. 
 It is only when the talents of different persons 
 are enlisted, and opposite opinions are contend- 
 ed for, that questions are traced in all their 
 bearings, and the grounds of an equitable 
 decision are fully exhibited. 
 
 212. The importance of controversy may be 
 inferred from the use, which has been made of 
 it, in every period of the world. It has been 
 adopted, as the principal mode of transacting 
 
RULES OF CONTROVERSY. 159 
 
 business, in the halls of legislation and in courts 
 of justice, where questions of the deepest con- 
 cern to individuals and communities are decid- 
 ed. The minds of youth have been trained 
 to it in seminaries of education, where the 
 practice of disputation, in various forms, ha I 
 been preserved, as a salutary discipline of the 
 mental powers. 
 
 213. As controversy, especially when carried 
 on from motives of victory or reputation, is 
 liable to be productive of evil rather than of 
 good, it is incumbent on all, who engage in it, 
 from whatever motives, to observe rigorously 
 those laws and principles, by which the former 
 may be avoided and the latter secured. The 
 following rules, sometimes called canons of 
 controversy, have been highly approved by 
 writers of learning and discernment.* 
 
 214. Rule 1st. The terms, in which the ques- 
 tion in debate is expressed, and the precise point 
 at issue, should be so clearly defined, that 
 there could be no misunderstanding respect 
 them. If this be not done, the dispute is liable 
 to be, in a great degree, verbal. Arguments 
 
 * These rules are taken, with slight alterations, from the lectures 
 of Dr. Hey, Norrisian Professor in the University of Cambridge. 
 They may also be found in Kirwan's Logick, vol. ii. 
 
160 RULES OF CONTROVERSY. 
 
 will be misapplied, and the controversy pro- 
 tracted, because the parties engaged in it have 
 different apprehensions of the question. 
 
 215. Rule 2d. The parties should mutually 
 consider each other, as standing on a footing of 
 equality in respect to the subject in debate. 
 Each should regard the other as possessing 
 equal talents knowledge, and desire for truth, 
 with himself ; and that it is possible, therefore, 
 that he may be in the wrong, and his adversary 
 in the right. In the heat of controversy, men 
 are apt to forget the numberless sources of 
 error, which exist in every controverted sub- 
 ject, especially of theology and metaphysicks. 
 Hence arise presumption, confidence, and 
 arrogant language ; all which obstruct the 
 discovery of truth. 
 
 216. Rule 3d. All expressions, ivhich are 
 unmeaning, or without effect in regard to the 
 subject in debate, should be strictly avoided. 
 All expressions may be considered as unmean- 
 ing, which contribute nothing to the proof of 
 the question ; such as desultory remarks and 
 declamatory expressions. To these may be 
 added all technical, ambiguous, and equivocal 
 expressions. These have a tendency to dazzle 
 
RULES OF CONTROVERSY. 161 
 
 and bewilder the inind, and to hinder its clear 
 perception of the truth. 
 
 217. Rule 4th. Personal reflections on an 
 adversary should in no instance be indulged. 
 Whatever be his private character, his foibles 
 arc not to be named nor alluded to in a con- 
 troversy. Personal reflections are not only 
 destitute of effect, in respect to the question 
 in discussion, but they are productive of real 
 evil. They obstruct mental improvement, and 
 are prejudicial to publick morals. They indi- 
 cate in him, who uses them, a mind hostile to 
 the truth ; for they prevent even solid argu- 
 ments from receiving the attention, to whicl 
 they are justly entitled. 
 
 218. Rule 5th. No one has a right to accuse 
 his adversary of indirect ?notives. Arguments 
 are to be answered, whether he, who offers 
 them, be sincere or not, especially as his want 
 of sincerity, if real, could not be ascertained. 
 To inquire into his motives, then, is useless. 
 To ascribe indirect ones to him is worse than 
 useless ; it is hurtful. 
 
 219. Rule 6th. The consequences of any doc- 
 trine are not to be charged on him, icho maintains 
 it, unless he expressly avows them. If an abs: 
 
 14* 
 
162 RULES OF INTERPRETATION. 
 
 consequence be fairly deducible from any doc- 
 trine, it is rightly concluded that the doctrine 
 itself is false ; but it is not rightly concluded, 
 that he, who advances it, supports the absurd 
 consequence. The charitable presumption, in 
 such a case, would be, that he had never made 
 the deduction ; and that, if he had made it, he 
 would have abandoned the original doctrine. 
 
 220. Rule 7th. As truth, and not victory, 
 is the professed object of controversy, whatever 
 proofs may be advanced, on either side, should 
 be examined with fairness and candour; and any 
 attempt to ensnare an adversary by the arts of 
 sophistry, or to lessen the force of his reaso?iing, 
 by wit, cavilling, or ridicule, is a violation of 
 the rules of honourable controversy. 
 
 CHAPTER SEVENTEENTH. 
 
 RULES OF INTERPRETATION. 
 
 221. To ascertain the true meaning of a 
 written document is often difficult and embar- 
 rassing, even when it is of recent date and in 
 our own language ; but the difficulty is greatly 
 enhanced, when the writing is in a foreign 
 language, or has descended from ancient times. 
 
RULES OF INTERPRETATION. 163 
 
 222. The circumstances, which aggravate 
 the labour of the interpreter, are numerous, and 
 of various kinds. No branch of knowledge is 
 entirely exempt from them ; but they exist in 
 the greatest degree in those sciences, which 
 involve our most important interests, both 
 sacred and civil. For this reason, principles 
 and rules of interpretation have been carefully 
 formed for developing the true meaning of the 
 sacred Scriptures and of legal instruments. 
 
 223. The design of interpretation is to 
 ascertain the real intention of the writer ; to 
 develope the true meaning of his words, where 
 they are obscure or ambiguous ; and to deter- 
 mine what was his design, where his words do 
 it but imperfectly. The following rules are of 
 a general character, and may be employed 
 with equal advantage, in explaining writings 
 of every kind : 
 
 224. Rule 1st. The interpreter of a written 
 document must have a thorough knowledge of 
 the language, in which it is written. 
 
 225. Rule 2d. He must possess an intimate 
 acquaintance with the subject of the writing. 
 Many words have different significations in 
 different sciences and arts ; and the particular 
 
?.".ii: :.- :: :i: ;; i: .-.: :;>. 
 
 ■---: - ^;:, :l „.;:_:'_-:-;■ e:c v:„:*: ::. 
 
 The true inte rpr e ration of a 
 "".".' .._ vi ::..:— 1 .:z:~. j; ■;:" *..:.-: 
 c„in;:~: ;: . - i_:i_:;. IT..- :. e-i'il :ir : ■•vi: ::' 
 mind, his temperament, his vocation, and 
 especially his political or r eligiocs tenets, may 
 bare had an influence, lor which some allow- 
 
 227. Rule 4th. If the writing to be interpret- 
 •:-: ':.. ::' il::-l: ii*:.:„: ::_:-::;-:-: =!:■:]: 
 v:v;:-.„:„v e ri..:^i^: ::!:.= :ei: : Lr.i.:: 
 it has descended to him as it came from the 
 author, without any corruptions or interpola- 
 tions from other ban 
 
 - - - " 
 
 be well acquainted with the ~ of the coon- 
 
 ind of th aich his author wrote, 
 
 rds have different meanings in different ai 
 .:.i :..::- \:' : ::. -..;. .-.. .';/ .::.;:;:; ;.y -.;.•_ 
 
 rcomstances of 
 a local and temporary natu 
 
 229. Role 6th. The mind of the interpreter 
 should be whoL from all antecedent 1 
 
 in favour of a: .em, doctrine, or creed, 
 
RULES OF INTERPRETATION. 165 
 
 which might influence his judgment, in the 
 interpretation he is about to make. 
 
 JJO. Rule 7th. In making the interpretation 
 of a document, the subject and predict 
 
 ch proposition should be carefully distin- 
 guished; the various sentences and clau 
 should be construed in reference to each 
 other ; and the resulting of all the parts 
 
 should be connected and consistent. 
 
 231. Rule 8th. Words, which admit of 
 different* senses, should be taken in their most 
 common and obvious meaning, unless such a 
 construction lead to absurd consequences, or 
 be inconsistent with the known intention of 
 the writer. 
 
 - 2. Rule 9th. When any word or expres- 
 sion is ambiguous, and may, consistently with 
 common use, be taken in different senses, it 
 must be taken in that sense, which is agreeable 
 to the subject, of which the writer was treat- 
 ing. 
 
 -13. Rule 10th. Doubtful words and phra 
 must always be construed in such a sense 
 will make them produce some effect ; and not 
 in such a sense as will render them wholly 
 nugatory. 
 
 i 
 
166 RULES OF INTERPRETATION. 
 
 234. Rule 11 A. Violations of the rules of 
 grammar da not vitiate a writing, in which the 
 sense is distinctly expressed. When a pas- 
 sage is imperfect, or unintelligible, the inter- 
 preter is at liberty to supply such words, as 
 are manifestly necessary to render its sense 
 complete. But he is not allowed, in a sim- 
 ilar case, to expunge certain words from the 
 text, in order to give an intelligible meaning 
 to those that remain. 
 
 235. Rule 12th. When there are no special 
 reasons for the contrary, words should be con- 
 strued in their literal, rather than in their fio-- 
 urative sense ; relative words should be refer- 
 red to the nearest, rather than to a remote 
 antecedent ; and words, which are capable of 
 being understood in either, should be taken in 
 their generick, rather than in their specifick 
 sense. 
 
 236. Rule 13th. However general may be 
 the words, in which a covenant is expressed, it 
 comprehends those things, only, on which it 
 appears the parties intended to contract, and 
 not those, which they had not in view. But 
 when the object of the covenant is an univer- 
 sality of things, it comprehends all the parti cu- 
 
RULES OF IN 
 
 It) 7 
 J) 
 
 universality, 
 had no 
 
 lar things, which comp 
 even those, of which the 
 knowledge. 
 
 237. Rule 14th. Whatever is ohscure or 
 doubtful in a covenant should be interpreted 
 by the intention of the parties. If the inten- 
 tion of the parties does not appear from the 
 words of the covenant, it should be inferred 
 from the existing customs and usages of the 
 place, in which it was made. If the words of 
 a covenant contradict the well known intention 
 of the parties, this intention must be regarded 
 rather than the words.* 
 
 238. Rule 15th. When former interpreters 
 are appealed to, in order to establish the sense 
 of an ancient writing, those, cceteris paribus, 
 should be preferred, who were nearest the au- 
 thor, in time or place, as his children, pupils, 
 correspondents, or countrymen ; and who had, 
 therefore, better advantages for knowing his 
 mind, than more distant commentators. 
 
 * Sarti, Dialect. Instit. Kirwan, Logick. Le Clerc, Ars Critica. 
 Vattel, Law of Nations. Piutherforth, Lectures on Grotius. Gilbert, 
 Law of Evidence. Pothier on Obligations. Domat on the Civil Law. 
 
168 CONCLUDING REMARKS. 
 
 CONCLUDING REMARKS. 
 
 In the preceding summary, an attempt has 
 been made to state and explain those rules of 
 intellectual discipline, which may guide and 
 improve the reasoning faculties. As the work 
 is intended to be strictly elementary, general 
 principles only have been given, with such plain 
 examples, as might limit and illustrate their 
 meaning. The following remarks are subjoin- 
 ed for the use of those, who may wish to ex- 
 tend their inquiries on the subject of logick, 
 and the philosophy of the human mind. 
 
 Dr. Reid's analysis of Aristotle's Logick 
 contains a brief but comprehensive exposition 
 of the syllogistick system. A more full ac- 
 count of the categories, together with the vari- 
 ous laws of syllogistick reasoning, may be 
 found in the logical treatises of Burgersdicius 
 and of Le Clerc. 
 
 Of modern systems of logick, those of Watts 
 and of Duncan have been most approved. A 
 more recent and valuable treatise, than either 
 of these, is that of Kirwan. 
 
 Tt is essential to accurate reasoning to dis- 
 tinguish those first principles of human knowl- 
 
CONCLUDING REMARKS. 169 
 
 edge, which must be taken for granted, from 
 those propositions, which require proof. On 
 this subject the treatise of Father Buffier, en- 
 titled First Truths, Bcattie'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 true subject of moral reasoning, important 
 information may be derived from Gambier's 
 Introduction to Moral Evidence, and from the 
 first book of Campbell's Philosophy of Rhet- 
 orick. 
 
 For the general direction of the mind, in its 
 researches after truth, rules of a more practi- 
 cal nature may be found in Locke's Conduct 
 of the Understanding and Watts on the Im- 
 provement of the Mind. 
 
 The study of those authors, who reason 
 clearly and accurately, is one of the best 
 methods of improving the reasoning powers. 
 For this purpose, Berkeley on the Principles of 
 Human Knowledge, Wollaston on the Religion 
 15 
 
 
170 CONCLUDING REMARKS. 
 
 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 reflection. He should dwell on 
 the operations of his own mind, and mark the 
 difficulties, which prevent his arriving at clear 
 conclusions ; whether they arise from misap- 
 prehension of the subject, from the ambiguity 
 of language, from weakness in the power of 
 attention, or from the biases 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. 
 
NOTES AND ILLUSTRATIONS. 
 
 Note A, page 17. 
 
 I have used reflection and consciousness as synony- 
 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. 
 All 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 
 operations, it does not attend to them ; its attention is 
 turned solely to the external objects, about which those 
 operations are employed."* In another place he says, 
 that " attention to things external is properly called ob- 
 servation^ and attention to the subjects of our conscious- 
 ness, reflection." This definition of reflection is substan- 
 tially 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 
 
 * Intellectual Powers, Essay I. 
 
172 NOTES. 
 
 pay very little attention to their mental operations. But, 
 without some degree of attention, they would have no 
 consciousness of them whatever ; and so far as they do 
 attend to them, so far, according to Dr. Reid's own ac- 
 count, they reflect. 
 
 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 
 reflex 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 pre- 
 supposes the actual existence of that operation. It may 
 be examined afterwards by the assistance of memory, but 
 this subsequent examination cannot be denominated re- 
 flection, agreeably to the strict sense of that word. Are 
 we then to believe, that reflection and consciousness 
 are two 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 
 watching 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 
 of its own operations. Now, as he places reflection in 
 attention to the subjects of our consciousness, and it 
 
NOTES. 173 
 
 appears 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 perception 
 of its own acts and modes of existence. But reflection 
 is usually employed to express some degree of voluntary 
 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. 
 
 NoteB, 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 suffi- 
 cient 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 
 of a proposition is only an attribute of the subject ; and 
 15* 
 
174 NOTES. 
 
 in this light it must be viewed, in order to render the 
 proposition true. When, for example, we affirm that 
 saffron is }'ellow, we refer a single property to a subject, 
 in which it is known to coexist with several other prop- 
 erties. 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 colour. And we 
 proceed in the same way, when the predicate has no 
 greater extension than the subject, as when we affirm that 
 iron is susceptible of magnetical attraction. 
 
 In passing fiom 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 dog y a dog is an animal, and an animal is a 
 being, that has life, sense, &c. It is obvious that the first 
 subject contains each of the predicates that follow. 
 
 As, in an act of judgment, one thing is perceived to be 
 contained in another, so, in syllogistick reasoning, one 
 proposition is shown to be contained in another, that in 
 a third, and so on. This process has been aptly illus- 
 trated by a collection of boxes of different sizes, placed 
 one in another. In such a nest of boxes, it would be 
 natural to say of that which was placed first, and contain- 
 ed all the rest, that it was the largest box, and of that, 
 which was in the centre, and had no other in it," that it 
 was the least box. But, in giving names to the three 
 terms of a syllogism, this rule of common sense has been 
 violated. The less is made to contain the greater. The 
 predicate of the conclusion, which is contained in each 
 of the other two, is called the major term, and the sub- 
 
NOTES. 175 
 
 ject of the conclusion which contains both the others, is 
 called the minor term. 
 
 Note C, page 122. 
 
 This is true in that arrangement of parts, which renders 
 the syllogism (he most simple and the most perfect ; though 
 it will not hold in all those technical forms, in which it has 
 been expressed. 
 
 It may not be deemed wholly impertinent in this place 
 to give a brief description of that celebrated doctrine of 
 modes and figures, in which simple syllogisms are involv- 
 ed, in the ancient books of logick. By the mode of a 
 syllogism is meant the designation of the quantity and 
 quality of its propositions. By figure is meant the 
 situation of the middle term with respect to the major 
 and minor terms. As the middle term occurs in each 
 of the premises, it is susceptible of four different positions 
 in relation to the extremes. Hence four figures have 
 been invented. In the first, the middle term is the sub- 
 ject of the major proposition, and the predicate of the 
 minor. In the second, it is the predicate, and in the 
 third, the subject, of both the premises. In the fourth, it 
 is the predicate of the major premise, and the subject of 
 the minor. 
 
 Each of the four figures has several modes, which are 
 designated by the vowels A, E, I, ; characters, em- 
 ployed by logicians to denote the quantity and quality 
 of propositions. A, placed before a proposition, denotes 
 
176 NOTES. 
 
 that it is an universal affirmative ; E denotes an universal 
 negative ; I, a particular affirmative ; and O, a particular 
 negative. To assist the memory, the following couplet 
 was contrived : 
 
 Asserit A, negat E, verum generaliter ambae. 
 Asserit I, negat O, sed particularity ambo. 
 
 As all the possible combinations of three of these four 
 letters, in three propositions, amount to sixty-four, this 
 number of modes might be formed. But, of these, fifty- 
 three are excluded by certain established rules, and one 
 rejected, as useless ; leaving only ten, that are considered 
 as legitimate. Several of these are repeated in different 
 figures, so as to make, in the whole, nineteen conclusive 
 modes. Each mode is furnished with an appropriate 
 name, consisting of three syllables, and containing three 
 of the vowels before named. The three syllables of the 
 mode are placed before the propositions of the syllogism, 
 in order that the vowel letter, which alone is regarded, 
 may indicate the quantity and quality of the proposition, 
 before which it stands. 
 
 To the first figure are given four modes ; which are 
 denominated Barbara, Celarent, Darii, Ferio. The second 
 figure has likewise four modes, namely, Ccesare, Cames- 
 tres, Festino, Baroco. The third has six modes, Darapti, 
 Felapton, Disamis, Datisi, Bocardo, Ferison. The fourth 
 has five modes, Bamarip, Camenes, Dimatis, Festapo, 
 Fresison. 
 
NOTES. N^ 177 
 
 177 
 
 These barbarous words have been thus formed into hex- 
 ameter verses : 
 
 Barbara, Celarent, Darii, Ferio quocpie, primse. 
 Caesare, Camestres, Festino, Baroco, secundac. 
 :i Darapti sibi vindicat atque Felapton ; 
 Disamis, Datisi, Bocardo, Ferison. 
 
 Camenes, Dimatis, Festapo, Fresison. 
 
 EXAMPLES. 
 
 -lire First. 
 
 o 
 
 Bar- Every animal has sensation; 
 
 Ba- Every man is an animal ; 
 
 Ha. Terefore every man has sensation. 
 
 Ce- No opinions, hurtful to the morals of society, 
 
 should be embraced ; 
 La- Atheistical sentiments are hurtful to the morals 
 
 of society ; 
 Rent. Therefore atheistical sentiments should not be 
 
 embraced. 
 
 Da- All good men love peace ; 
 
 Ri- Some statesmen are good men ; 
 
 I. Therefore some statesmen love peace. 
 
 Ft- No man of dissolute habits is a safe companion ; 
 Ri- Some men of learning are dissolute in their 
 
 habits ; 
 O. Therefore some men of learning are not safe 
 
 companions. 
 
178 NOTES. 
 
 Figure Second. 
 
 Ca- Every virtuous man is fit to be believed ; 
 
 Mes- No liar is fit to be believed ; 
 
 Tres. Therefore no liar is a virtuous man. 
 
 Ba- Every true patriot tries to promote the publick 
 
 good; 
 Ro- Some men in high stations do not try to promote 
 
 the publick good ; 
 Co. Therefore some men in high stations are not 
 
 true patriots. 
 
 Figure Third. 
 
 Da- All good Christians will be saved ; 
 
 Rap- All good Christians have sinned ; 
 
 Ti. Therefore some, who have sinned, will be saved. 
 
 Examples of the other modes may readily be formed. 
 
 FINIS. 
 
RETURN TO the circulation desk of any 
 University of California Library 
 or to the 
 NORTHERN REGIONAL LIBRARY FACILITY 
 Bldg. 400, Richmond Field Station 
 University of California 
 Richmond, CA 94804-4698 
 
 ALL BOOKS MAY BE RECALLED AFTER 7 DAYS 
 
 • 2-month loans may be renewed by calling 
 (510)642-6753 
 
 • 1-year loans may be recharged by bringing 
 books to NRLF 
 
 • Renewals and recharges may be made 4 
 days prior to due date. 
 
 DUE AS STAMPED BELOW 
 
 JUN 2 3 2000 
 
 ; 2,000 (11/95) 
 
GENERAL LIBRARY U.C. BERKELEY 
 
 BOQOSbfiMBb