Elements of logic, comprising the substance of the article in the Encyclopædia metropolitana; with additions, &c

Front matter

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, el an 4 eee am Aa

A) ee ae A Re AY OB

Dedication

fact, may eusily be referred in the mind to the preson from whom we have derived it: but scientific truths, when thoroughly embraced, become much more a part of the mind, as it were; since they rest, nut on the authority of the instructor, but on reasoning from data, which we ourselves furnish ;* they are scions engrafted on the stems previously rooted in our own soil; and we are apt to confound them with its indigenous productions.

You yourself also, I have reason to believe, have forgotten the greater part of the assistance you have afforded in the course of conversations on the subject; as ] have found, more than once, that ideas which I distinetly remembered to have received from you, have not been recognized by you when read or repeated. As far, however, as I can recollect, though there is no part of the following pages in which I have not, more or less, received valuable suggestions from you, I believe you have contributed less to the Analytical Outline, and to the Treatise on Fallacies, and more, to the subjoined dissertation, than to the rest of the work.

[ take this opportunity of publicly declaring, that as, on the one hand, you are not responsible for any thing contained in this work, so, on the other hand, should you ever favour the world with a publication of your own on the subject, the coincidence which will doubtless be found in it with many things here brought forward as my own, is not to be regarded as any indicatics of plagiarism, at least on your side.

Preface

Tue following Treatise contains the substance of tha Article “ Locic” in the Encyclopedia Metropolitana It was suggested to me that a separate publication of i: might prove acceptable, rot only to some who are not subscribers to that work, but also to several who are; but who, for convenience of reference, would prefer a more portable volume. In facta number of individuals had actually formed a design (prevented only by this publication) of joining together to have the Article reprinted for their own private use.

I aceordingly revised it, and made such additions, chiefly in the form of Notes, as I thought likely to increase its utility.

When applied to to contribute the Article, I asked and obtained permission from Dr. Copleston (now Bishop of Llandaff) to make use of manuscripts compiled in great measure from what I had heard from him in conversations on the subject, or which he had read to me from his common-place book, interspersed with observations of myown. ‘These manuscripts [ had drawn up and was in the habit of employing, for the use of my own pupils.

In throwing them into a form suitable for the Encyclopedia, and in subsequently enlarging the Article into the present volume, I have taken without scfuple whatever appeared most valuable from the works of former writers ; especially the concise, but in general @cturate, treatise of Alcrich. Rut while I ackno-

1* vi PREFACE;

ledge my obligations to my predecessors, of whose la: bours I have largely availed myself, I do not profess to be altogether satisfied with any of the treatises that have yet appeared; nor have I accordingly judged it any unreasonable piesumption to point out what seem to me the errors they contain. Indeed, whatever deference an Author may profess for the authority of those who have preceded him, the very circumstance of his publishing a work on the same subject, proves that he thinks theirs open toimprovement. In censuring, however, as I have had occasion to do, several of the doctrines and explanations of logical writers, and of Aldrich in particular, I wish it to be understood that this is not from my having formed a low estimate ol the merits of the Compendium drawn up by the Author just mentioned, but, on the contrary, from its popularity, (it being the one commonly used at Oxford)—from ihe impossibility of noticing particularly all the points | in which we agree,—and from the consideration that errors are the more carefully to be pointed out in preportion to the authority by which they are sanctioned I have to acknowledge assistance received from sev

eral friends who have at various times suggested re marks and aiterations. But I cannot avoid particular izing the Rev. J. Newman, Fellow of Oriel College who actually composed a considerable portion of th: work as it now stands, from manuscripts not designer for publication, and who is the original author of sev eral pages. Some valuable illustrations of the impor tance of attending to the ambiguity of the terms uset in Political Economy, were furnished by the kindness of my friend and former pupil, Mr. Senior, of Magda len College, and now Master in Chancery, who preceded me in the office of Professor of Political Economy at Oxford, and afterwards was appointed to the same at King’s College, London. ‘They are printed in the Appendix. But the friend to whom it is inscribed haa contributed far more, and that, in the most important

PRE ace Cu parts, than all others together; so uch, ‘ndeed, thas, though there is in the treatise ncthing ot Dis which has not undergone such expansion or modification as leaves me solely responsible for the whole, there is not a little of which | cannot fairly claim to be the Author.

Each successive edition has been revised with the utmost care. But though the work has undergone jot only the close examination of myself and several friends, but the severer scrutiny of determined opponents, { am happy to find:that no material errors have been detected, nor any considerable alterations found necessary.

On the utility of Logic many writers have said much in which | cannot coincide, and which has tended to bring the mers into unmerited disrepute. By representing Logic as furnishing the sole instrument for the discovery of truth in all subjects, and as teaching the use of the zntellectual faculties in general, they raised expectations which could not be realised, anc which naturally led to a re-action. The whole system, whose unfounded pretensions had been thus blazoned forth, came to be commonly regarded as utterly futile and empty ; like several of our most valuable medicines, which, when first introduced, were proclaimed, each, as a panacea, infallible in the most opposite disorders ; and which consequently, in many instances, fell for a time into total disuse; though, after a long interval, they were established in their just estimation, and em ployed conformably to their real properties.

In one of Lord Dudley’s (lately published) letters to: Bishop Copleston, of the date of 1814, he adduces a

resumption against the study of Logic; that it was sedu-

ously cultivated during the dark periods in which the intellectual powers of mankind seemed nearly paralyzed—when no discoveries were made, and wlen various errors were wide-spread and deep-rooted: and that when the mental activity of the world revived, and philosophical inquiry flourished and bore its fruits, logical etudies fell into decay ard contempt. And this I hava viii. PREFACE introduced in tae ** Elements of Rhetoric,” (fart fl

Ch. iit § 2,) among other examples of a presumption not in itself unreasonable, but capable of being rebutted by a counter-presumption. When any study has been unduly or unwisely cultivated to the neglect of others, and has even been intruded into their province, there is a presumption that a re-action* will ensue, and an equal. ly excessive contempt, or dread, or disgust, succeed

And in the present instance, the mistaken and absurd cultivation of Logic during Ages of great intellectual darkness, might have been expected to produce, ina subsequent age of comparative light, an association in men’s minds, of Logic, with the idea of apathetic ignorance, prejudice, and adherence to error; so that the legitimate uses, and just value of the science (supposing it to have any) would be likely to be scornfully overlooked. Our ancestors having neglected to raise fresh crops of corn, and contented themselves with vainly threshing over and over the same straw and winnowing the same chaff, it might have been anticipated that their descendants would, for a time, regard the very operations of threshing and winnowing with contempt, and would attempt to grind corn, straw and chaffali together.

The revival of a study which had for a long time been regarded as an obsolete absurdity, would probably have appeared to many persons, thirty years ago, as an undertaking far more difficult than the introduction ot some new study ;—as resembling rather the attempt to restore life to one of the antediluvian fossil-plants, than the rearing of a young seedling into a tree.

It is a curious circumstance’ that the very person to whc u the letter just alluded to was addressed should have lived to witness so great a change of public opinion brought about (in a great degree through his oton instrumentality+) within the short interval--indeed within a small portion of the interval-—between the writing

* See ‘“‘ Charge,” 1843. t See Dedication.

: a “x

PREFACE iZ éf that setter and its publication, that the whole ground pf the presumption alluded to has been completely cat away. During that interval, the treatise which was with his aid composed, and by his permission inserted © in the Encyclopedia, attracted so much attention as to pecasion its sepaiate publication, ina volume which has been frequently reprinted, not only in England, but in the United States of Amorica; where it is in use, I believe, in every one of their Colleges. Add to which, the frequent allusions (compared with what could have been met with twenty or thirty years ago) to the subject of Logic, by writers on various subjects. And moreover several other treatises on the subject, either original works or abridgements, have been making theit appearance with continually increased frequency of late years. Some indeed of these have little or nothing in common with the present work except the title. But even that very circumstance is so far encouraging, as indicating that the name of this science instead of exciting, as fopnarly an almost universal prejudice, is considered as likely to prove a recommendation. Certainly Lord Dudley, wére he now living, would not speak of the general neglect and contempt af Logic, though every branch of Science, Philosophy, and Lite rature, have flourished during the interval.

_ To explain fully the utility of Logic is what can be done only in the course of an explanation of the sys: tem itself. One preliminary*observation only (for the original suggestion of which I am indebted to the same friend to whom this work is inscribed) it may be worth while to offer in this place. If it were inquired what is to be regarded as the most appropriate intellectual occupation of MAN, as man, what would be the answer? ‘The Statesman is engaged with political affairs; the Soldier with military; the Mathematician, with the Benperties of nvipbers and magnitudes; the Merchant, with commercial concerns, &c.; but in whatare all an? each of these employed ?-—-employed, I mean, as mea x PREFACE.

ior there wre many modes of exercise of the facultiea mentalas wellas bodily, which are in great measure com

mon to us with the lower animals. Evidently, in Rea

soning. They are all occupied in deducing, well or 11]

Conclusions from Premises; each, concerning the sub. ject of his own particular business. If, therefore, it be found that the process going on daily, in each of so many different minds, is, in any respect, the same, and il the principles on which it is conducted can be reduced to a regular system, and if rules can be deduced from from that system, for the better conducting of the process, then, it can hardly be denied that such a system and such rules must be especially worthy the attention, —not of the members of this or that profession merely, but—of every one who is desirous of possessing a cultivated mind. To understand the theory of that which is the appropriate intellectual occupation of Man in general, and to learn to do that well, which every one will and must do, whether well or ill, may surely be consi. dered as an essential part of a liberal education.

Even supposing that no practical improvement in argumentation resulted from the study of Logic, it woula not by any means follow that it is unworthy of atten tion. The pursuit of knowledge on curious and interesting subjects, for its own sake, is usually reckoned no misemployment of time; and is considered as, incidentally, if not directly, useful to the individual, by the exercise thus afforded to the mental faculties. All wha study Mathematics are not training themselves to become Surveyors or Mechanics; some knowledge ot Anatomy and Chemistry is even expected in a man iiberally educated, though without any view to his practising Surgery or Medicine. And the investigation of a process which is peculiarly and universally the occupa tion of Man, considered as Man, can hardly be reckoned a less philosophical pursuit than those just instanced

It has usually been assumed, however, in the case of the present subject, that a theory which does not

PREF:CE. B tend to the improvement cf practice is utterly unworthy of regard; and then, it is contended that Logic has ne such tendency, on the plea that men may and do reason correctly without it: an objection which would equally apply in the case of Grammar, Music, Chemis. try, Mechanics, &c., in all of which systems the prac lice must have existed previously to the theory.

But many who allow the use of systematic principles in other things, are accustomed to cry up Common- Sense as the sufficient and only safe guide in Reasoning Now by Common-Sense is meant, I apprehend, «when the term is used with any distinct meaning,) an exercise of the judgment unaided by any Art or syste of rules: such an exercise as we must necessarily employ in numberless cases of daily occurrenee; in which,

aving no established principles to guide us,—no line of procedure, as it were, distinctly chalked out,—we m ist needs act on the best extemporaneous conjectures we can form. He who is eminently skilful in doing this, is said to possess a superior degree of Common Sense. But that Common-Sense is only our second best guide—that the rules of Art, if judiciously framed are always desirable when they can be had, is an as sertion, for the truth of which I may appeal to the tes. timony of mankind in general; which is so much the more valuable, inasmuch as it may be accounted the “estimony of adversaries. For the generality have a strong predilection in favour of Common-Sense, except in those pvints in which they, respectively, possess the knowledge of a system of rules; but in these points they deride any one who trusts to unaided Common. Sense. A sailor e. g. will, perhaps, despise the preseasions of medical men, and prefer treating a disease by Common-Sense : but he would ridicule the proposal of navigating a ship by Common-Sense, without regard to the maxims of nautical art. A physician, again, will perhaps contemn Systems of Political-Economy,*

* See Senior's Introductory Lecture on political Economy, p. 28 ji-,

Eli PREFACE.

of Logic, or Metaphysics, and insist on the supens wisdom of trusting to Common-Sense in such matters

but he would never approve of trusting to Common. Sense in the treatment of diseases. Neither, again, would the Architect recommend a reliance on Common- Sense alone, in building, nor the Musician, in music. to the neglect of those systems of rules, which, in their respective arts have been deduced from scientific reasoning aided by experience. And the induction mighi be extended to every department of practice. Since, therefore, each gives the preference to unassisted Common-Sense only in those cases where he himself has nothing else to trust to, and invariably resorts to the rules of art, wherever he possesses the knowledge of them, it is plain that mankind universally bear thei testimony, though unconsciously and often unwillingly, to the preferableness of systematic knowledge to conjectural judgments.

There is, however, abundant room for the employ ment of Common-Sense in the application of the system. To bring arguments, out of the form in which they are expressed in conversation and in books, into the regular logical shape, must be of course, the business of Common-Sense, aided by practice, for such arguments are, by supposition, not as yet within the perwuce of Science; else they would not be irregular, but would be already strict syllogisms. To exercise the learner in this operation, 1 have subjoined in the Appendix, some examples both of insulated arguments, and (in the later editions) of the analysis of argumentative works. It should be added, however, that a large portion of what is usually introduced into Logital treatises, relative to the finding of Arguments,—the different kinds of them, &c., 1 have referred to the head of Rhetoric, and treated of in a work on the Elementa of that Art.

It was doubtless from a strong and deliberate convictio» of the atvantages, direct and indirect. accruing

PREFACA xi from an acquaintance with Logic, \hat the University at Oxford, when re-modelling their system, not only retained that branch of study, regardless of the clamours of many of the half-learned, but even assigned a prominent place to it, by making it an indispensable art of the Examination for the first Degree. This ast circumstance, however, I am convinced, has, in a great degree, produced an effect opposite to what was designed. It has contributed to lower instead of exalting, the estimation of the study; and to withhold from ‘t the earnest attention of many who might have applied to it with profit. I am not so weak as to imagine that any System can ensure great proficiency in ‘any pursuit whatever, either inall students, or ina very large proportion of them: ‘we sow many seeds to obtain a few flowers ;” but it might have been expected (and doubtless was expected) that a majority at least of successful candidates would derive some benefit worth mentioning from their Icgical pursuits ; and that a considerable proportion of the distinguished candidates would prove respectable, if not eminent logicians Such expectations [ do not censure as unreasonable, 01 such as I might not have formed myself, had 1 been called upon to judge at that period when our experience was all to come. Subsequently, however, experience has shown that those expectations have been very in adequately realized. ‘The truth is, that a very smal] proportion, even of distinguished students, ever become proficients in Logic; and that by far the greater part pass through the University without knowing any thing at all of the subject. 1 donot mean that they have not learned by rote a string of technical terms; but that they understand absolutely nothing whatever of the principles of the science I am aware that some injudicious friends of Oxfora will censure the frankness of this avowal. | have only to reply that such is the truth; and that I think too wel. of, and know far toe well, the University in which a PREFACE,

[ have been employed in various academical occupa tions above a quarter of a century, to apprehend dan- Rc to her reputation from declaring the exact truth. 7ith all its defects, and no human institution is perfect, the University would stand, I am convinced, higher in public estimation than it does, were the whole truth, and nothing but the truth, in all points respecting it, more fully known. But the scanty and partial success of the measures employed to promote logical studies is the consequence, 1 apprehend, of the universality of the requisition. . That which must be done by every one, will, of course, often be done but indifferently ; and when the belief is once fully established, which it certainly has long been, that any thing which is indispensable to a testimonial, has little or wothing to do with the attainment of honors,* the lowest standard soon becomes the established one in the minds of the greater number; and provided that standard be once reached, so as to secure the candidate from rejection, a greater or less proficiency in any such branch of study is regarded as a matter of indifference, as far as any views of academical distinction are concerned. .

Divinity is one of these branches, and to this also most of what has been said concerning Logic might be considered as equally applicable ; but, in fact, there are several important differences between the two cases. In the first place, most of the students who are designed for the Church, and many who are not, have a value for theological knowledge, independently of the requisition of the sck.ools ; and on that ground do not confine their views to the lowest admissible degree of proficiency; whereas this can be said of very few in the case of Logic. And moreover, such as design to become candidates for holy Orders, know that ano-

*In the last framed Examination-statute an express declaration hes been inserted, that profi-iency in Logic is to have weight & tee assignment of honours.

PREFACE. XV her examination in Theology awaits them. But a consideration, which is still more to the present purpose, is, that Theology, not being a Science, admits o! infinite degrees of proficiency, from that which is within the reach of a child, up to the highest that is attainable by the most exalted genius; every one of which degrees is inestimably valuable as far as it goes. If any one understands tolerably the Church-catechism, or even half of it, he knows something of divinity ; and that something is incalculaby preferable to nothing But it is not so with a Science ; one who does not understand the principles of Euclid’s demonstrations, whatever number of questions and answers he may have learnt by rote, knows absolutely nothing of Geometry : unless he attain this point, all his labour is utterly lost; worse than lost, perhaps, if he is led ta believe that he has learnt something of Mathematics, when, in truth, he has not. And the same is the case with Logic, or any other Science. It does not admit of such various degrees, as a knowledge of religion. Of course I am far from supposing that all who understand any thing, much or little, of a certain Science, stand on the same level; but I mean, what is surely undeniable, that one who does not embrace the fundamental principles, of a Science, whatever he may have taken on authority, and learned by rote, knows, properly speaking, nothing of that science. And such, | have no hesitation in saying, is the case with a considerable proportion even of those candidates who obtain testimonials, including many who gain’ distinction. There are some persons (probably not so many as one in ten, of such as have in other respects tolerable abilities,) who are physically incapable of the degree of steady abstraction requisite for really embracing the principles of Logic or of any other Science, whatever pains may be taken by themselves or their teachers Bul there is a much greater number to wham this is a gieat difficulty, though net an impossibility ; and whe

£¥i PREFACE naving of course, a strong disinclination to such a study look naturally to the very lowest admissible standard And the example of such examinations in Logic as musi be expected in the case of men of these descriptions, tends, in combination with popular prejudice, to degrads the study altogether in the minds of the generality.

it was from these considerations, perhaps that it was proposed, a few years ago, to leave the study of Logic altogether to the option of the candidates: but the sug gestion was rejected ; the majority appearing to think (in which opinion I most fully coincide) that, so strongly as the tide of popular opinion set against the study, the result would have been, within a few years, an almost universal neglect of that science. Matters were accordingly left, at that time, in respect of this point, on their former footing ; which I am convinced was far preferable to the proposed alteration. |

But a middle course between these two was suggested, which I was persuaded would be infinitely preferable to either ; a persuasion whichl had long entertained, and which is confirmed by every day’s observations and reflections ; of which, few persons, I believe, have bestowed more on this subject. Let the study of Logic, it was urged, be made optzonal to those who are merely candidates for a degree, butindispensable to the attainment of academical honours ; ana the consequence would be, that it would speedily begin and progressively continue, to rise in estimation and to be studied with rea! profit. The examination might then, it was urged, without any hardship, be made a strict one; since na one could complain that a certain moderate degree ot scientific ability, and a resolution to apply to a certain prescribed study, should be the conditions of obtainin distinction. The far greater part would still study Logic; since there would be (as before) but few whe would be willing to exclude themselves from the possibility of obtaining distinction; but it weuld be studied with a very different mind, when ennobled, as it were

PREFACE. xv ny being made putt of the passport to University ron ours, and when a proficiency in it came to be regardea generally as an honourable distinction. And in pro« portion as the number increased of those who really understood the science, the number, it was contended, would increase of such as would value it on higher and better grounds. + would in time come to be better known and better appreciated by all the well-informed part of society: and lectures in Logic at the University would then, perhaps, no longer consist exclusively of an explanation of the mere elements. This would be necessary indeed for beginners; but to the more advanced students, the tutors would no more think of lecturing in the bare rudiments, than of lecturing in the Latin or Greek Grammar ; but, in the same manner as they exercis? their pupils in Grammar, by reading with them Latin and Greek authors with continual reference to grammer-rules, so, they would exercise them in Logic by reading some argumentative work, requiring a” analysis of it on logical principles.

These effects could not indeed, it was acknowledged, be expected to show themselves fully till after a considerable lapse of time ; but that the change would begin to apprar, (and that very decidedly) within three or four years, was confidently anticipated.

To this it was replied, that it was most desirable that no one should be allowed to obtain the Degree of B.A. without a knowledge of Logic. This answer carries a plausible appearance to those unacquainted with the actual state of the University ; though in fact it is totally irrelevant. For it goes on the supposition, that hitherto this object has been accomplished ;—that every one who passes his examination does possess a knowledge of Logic; which is notoriously not the fact, not ever can be, without some important change in some | part of our system. The question therefore is, not, as the above objection would seem to imply, whether a real, profitable knowledge of Logic shall be strictly ze vin PREFACE vuired of every candidate for a Degree, toi this in lae never has been done) but whether, in the attempt to accomplish this by requiring the form of a logical examination from every candidate without exception, we shall continue to degrade the science, and to let this part oi the examination be regarded as a mere form, by many who might otherwise have studied Logic in earnest. _and with advantage :—whether the great majority of candidates, and those too of a more promising description, shall lose a real and important benefit, througr the attempt, (which, after all, experience has proved to be a vain attempt) to comprehend in this benefit a very small number, and of the least promising.

Something of an approach to the proposed alteration, was introduced into the Examination-statute passed in 1830; in which, permission is granted to such as are candidates merely for a testimonial, to substitute for Logic a portion of Euclid. I fear, however, that little or nothing will be gained by this; unless indeed_the Examiners resolve to make the examinations in Logic far stricter than those in Euclid. For since every one whe is capabie of really understanding Euclid must be also eapable of Logic, the alteration does not meet the case of those whose inaptitude for Science is invincible ; and these are the very description of men whose (so-called logical-examinations tend to depress the science. Those ~ ew who really are physically incapable of scientific reasoning, and the far greater number who fancy themselves so, or who at least will rather run a risk than surmount their aversion, and set themselves to study in earnest,—all these will be likely, when the alternative is proposed, to prefer Logic to Euclid; because in the latter, itis hardly possible, at least not near so easy as in Logic, to present the semblance of preparation by learning questions and answers by rote:—in the cant phrase of undergraduates, by getting crammed. Experience has proved this, in the case of the Responsion. examinationy, where the alternative of Logic or Enclid

PREFACE. XL nas always been proposed to the candilates; of whom those most averse to Science, or incapable of it, are al most always found to prefer Logic.