Reid's essays on the intellectual powers of man

Chapter I. Explication of Words, .• ."" ' . . 219

II. Principles taken for granted, . . . 230

III. Of Hypotheses, ' . ' . . . 234

IV. Of Analogy, ... . 236 V. Of the proper means of Knowing the operations of the Mind, 238

VI. Of the difficulty of Attending to the operations of our own Minds, 240

V "II. Division of the powers of the Mind, . . . 242

VIII. Of Social [and Solitary] operations of Mind. . 244

ESSAY II. — Of the Powers we have by means of our External Senses.

Chapter I. Of the Organs of Sense, .... 245

II. Of the Impressions on the Organs, Nerves, and Brain, 247

III. Hypothesis concerning the Nerves and Brain, . 248

IV. False Conclusions drawn from the impressions before mentioned, 253

V. Of Perception, . . . .258

VI. What it is to Account for a Phenomenon in Nature, 260

VII. Sentiments of Philosophers about the Perceptions of External

objects ; and first, of the theory of Father Malebranche 262 VIII. Of the Common Theory of Perception ; and of the sentiments of

the Peripatetics, and of Des Cartes, . . 267

IX. The sentiments of Mr Locke, . . . 275

X. The sentiments of Bishop Berkeley, . . . 280

XI. Bishop Berkeley's sentiments of the nature of Ideas, 287

XII. The sentiments of Mr Hume, . . . 292

XIII. The sentiments of Anthony Arnauld, . . 295

XIV. Reflections on the Common Theory of Ideas, . . 298 XV. Account of the system of Leibnitz, " . ' . 306

XVI. Of Sensation, . . . . ■ . 310 XVII. Of the Objects of Perception ; and first, of Primary and Secondary Qualities, .... 313 XVIII. Of other objects of Perception, . . . 319 XIX. Of Matter and of Space, .... 322 XX. Of the Evidence of Sense, and of Belief in general, . 326* XXI. Of the Improvement of the Senses, . . . 330 XXII. Of the Fallacy of the Senses, ... 334

VI CONTENTS.

Page ESSAY III.— Op Memory.

Chapter I. Things obvious and certain with regard to Memory, . 339

II. Memory an original faculty, . . . 340

III. OfJ>uration, ..... 342

IV. Of Identity, ..... 344 V. Mr Locke's account of the Origin of our Ideas, and particularly

of the idea of Duration, .... 346

VI. Mr Locke's account of our Personal Identity, . 350

VII. Theories concerning Memory, , . . 353

ESSAY IV Of Conception.

Chapter I. Of Conception, or Simple Apprehension in general, . 360

II. Theories concerning Conception, . . 368

III. Mistakes concerning Conception, *. . . 375

IV. Of the Train of Thought in the mind, . . 379

ESSAY V.— Of Abstraction.

Chapter I. Of General Words, .... 389

II. Of General Conceptions, . . . 391

III. Of general conceptions formed by Analysing objects, . 394

IV. Of general conceptions formed by Combination, . 398 V. Observations concerning the Names given to our general notions, 403

VI. Opinion of philosophers about Universals, . . 405

ESSAY VI.— Of Judgment.

Chapter I. Of Judgment in general, .... 413

•II. Of Common Sense, .... 421

III. Sentiments of philosophers concerning Judgment, . 426

IV. Of First Principles in general, • • . 434 V. The first principles of Contingent Truths. [ On Consciousness, ~\ 441

VI. First principles of Necessary Truths, . . 452

VII. Opinions, ancient and modern, about First Principles, . 462

VIII. Of Prejudices, the causes of error, . . 468

ESSAY VII.— Of Reasoning.

Chapter I. Of Reasoning in general, and of Demonstration, • 475

II. Whether Morality be capable of demonstration, . 478

■wJJI. Of Probable Reasoning, .... 481

IV. Of Mr Hume's Scepticism with regard to Reason, . 484

ESSAY VIII.— Of Taste.

Chapter I. Of Taste in general, .... 490

II. Of the Objects of taste, and first of Novelty, . 493

[II. Of Grandeur, .... 494

IV. Of Beauty, ..... 498

ESSAYS

ON THK

INTELLECTUAL POWERS OF MAN,

By THOMAS REID, D.D., F.R.S.E.,

PROFESSOR OF MORAL PHILOSOPHY IN THE UNIVERSITY OF GLASGOW, " Who bath put wisdom in the inward part* ?*— Job.

fcf" This impression of the " Essays on the Intellectual Powers," is made from the only authentic edition — that of 1785, in 4to. For the convenience of reference the pages of that edition are distinguished in the present ; and by these pages I shall always, in the notes, prospectively, quote. They will be found marked both in the text and on the lower margin — H.

Dedication

MR DUGALD STEWART,

LATELY PROFESSOR OF MATHEMATICS, NOW PROFESSOR OF MORAL PHILOSOPHY,

AND

Preface

than twenty years, in Lectures to a large body of the more advanced students in this University, and for several years before, in another University. Those who heard me with attention, of whom I presume there are some hundreds alive, will recognise the doctrine which they heard, some of them thirty years ago, delivered to them more diffusely, and with the repetitions and illustrations proper for such audiences.

I am afraid, indeed, that the more intelligent reader, who is conversant in such abstract subjects, may think that there are repetitions still left, which might be spared. Such, I hope, will consider, that what to one reader is a superfluous repetition, to the greater part, less conversant in such subjects, may be very useful. If this apology be deemed insufficient, and be thought to be the dictate of laziness, I claim some indulgence even for that laziness, at my period of life, [vii ]

You who are in the prime of life, with the vigour which it inspires, will, I hope, make more happy advances in this or in any other branch of science to which your talents may be applied.

Tho. Reid.

Glasgow College, June I, 1785.

PREFACE.

Human knowledge may be reduced to two general heads, according as it relates to body or to mind ; to things material or to things intellectual.*

The whole system of bodies in the universe, of which we know but a very small part, may be called the Material World ; the whole system of minds, from the infinite Creator to the meanest creature endowed with thought, may be called the Intellectual World. These are the two great kingdoms of nature-|* that fall within our notice ; and about the one, or the other, or things pertaining to them, every art, every science, and every human thought is employed ; nor can the boldest flight of imagination carry us beyond their limits.

Many things there are, indeed, regarding the nature and the structure both of body and of mind, which our faculties cannot reach ; many difficulties which the ablest philosopher cannot resolve : but of other

* See Stewan 's " Life and Writings of Reid," supra, p. 14 ; and his " Elements," vol. I., introduction ; Jouffroy, in the preface to his " Oeuvres de Reid," t. i., pp. 23-53. This important Preface will soon be made generally accessibleto the British public by a highly competent translator. — H.

t The term Natwe is used sometimes in a wider, sometimes in a narrower extension. When employed in its most extensive meaning, it embraces the two worlds of mind and matter. When employed in its more restricted signification, it is a synonyme for the latter only, and is then used in contradistinction to the former. In the Greek philosophy, the word Quo-i; was general in its meaning ; and the great branch of philosophy styled " physical or physiological," included under it not only the sciences of matter, but also th< se of mind. With us, the term Nature is mo e vaguely extensive than the terms, physics, ; h si a!, physiology, physiological, or even tnan the adjective natural ; whereas, in the philosophy of Germany, Natur, and its correlatives, whether of Greek or Latin derivation, are, in general, exprcssive-of the woild of matter in contrast to the world ol- intelligence. — H.

natures, if any other there be, we have no knowledge, no conception at all.

That everything that exists must be either corporeal or incorporeal is evident. But it is not so evident that every thing [2] that exists must either be corporeal or endowed with thought. Whether there be in the universe beings which are neither extended, solid, and inert, like body, nor active and intelligent, like mind, seems to be beyond the reach of our knowledge. There appears to be a vast interval between body and mind ; and whether there be any intermediate nature that connects them together, we know not.

We have no reason to ascribe intelligence, or even sensation, to plants ; yet there appears in them an active force and energy, which cannot be the result of any arrangement or combination of inert matter. The same thing may be said of those powers by which animals are nourished and grow, by which matter gravitates, by which magnetical and electrical bodies attract and repel each other, and by which the parts of solid bodies cohere.

Some have conjectured that the phenomena of the material world which require active force, are produced by the continual operation of intelligent beings : others have conjectured that there may be in the universe, beings that are active, without intelligence, which, as a kind of incorporeal machinery, contrived by the supreme wisdom, perform their destined task without any knowledge or intention.* But, laying aside conjecture, and all pretences to determine in things beyond our reach, we must

* Like the tripods of Vulcan—

PREFACE.

rest in this, that body and mind are the 01 ih kinds of being of which we can have any knowledge, or can form any conception. If there are other kinds, they are not discoverable by the faculties which God hath given us ; and, with regard to us, are as if they were not. [3]

As, therefore, all our knowledge is confined to body and mind, or things belonging to them, there are two great branches of philosophy, one relating to body, the other to mind. The properties of body, and the laws that obtain in the material system, are the objects of natural philosophy, as that word is now used- The branch which treats of the nature and operations of minds has, by some, been called Pneumatology.* And to the oneor the otherof these branches, the principles of all the sciences belong.

What variety there may be of minds or thinking beings, throughout this vast universe, we cannot pretend to say. We dwell in a little corner of God's dominion, disjoined from the rest of it. The globe which we inhabit is but one of seven planets that encircle our sun. What various orders of beings may inhabit the other six, their secondaries, and the comets belonging to our system, and how many other suns may be encircled with like systems, are things altogether hid from us. Although human reason and industry have discovered, with great accuracy, the order and distances of the planets, and the laws of their motion, we have no means of corresponding with them. That they may be the habitation of animated beings, is very probable ; but of the nature or powers of their inhabitants, we are perfectly ignorant. Every man is conscious of a thinking principle, or mind, in himself ; and we have sufficient evidence of a like principle in other men. The actions of brute animals shew that they have some thinking principle, though of a nature far inferior to the human mind. And everything about us may convince us of the existence of a supreme mind, the Maker and Governor of the universe. These are all the minds of which reason can give us any certain knowledge. [4]

The mind of man is the noblest work of God which reason discovers to us, and, therefore, on account of its dignity, deserves our study, "t* It must, indeed, be acknowledged, that, although it is of all objects the nearest to us, and seems the most within our reach, it is very difficult to attend to its operations so as to form a distinct notion

• Now properly superseded by the term Psychology ; to which no competent objection can be made, and which affords us — what the various clumsy peri, phrases in ue do not — a convenient adjective, psychological.— H.

t " On earth," says a forgotten philosopher, " there is nothing great but Man ; in man there is nothing great but Mind."— H.

[3—5]

of them ; and on that account there is no branch of knowledge in which the ingenious and speculative have fallen into so great errors, and even absurdities. These errors and absurdities have given rise to a general prejudice against all inquiries of this nature. Because ingenious men have, for many ages, given different and contradictory accounts of the powers of the mind, it is concluded that all speculations concerning them are chimerical and visionary.

But whatever effect this prejudice may have with superficial thinkers, the judicious will not be apt to be carried away with it. About two hundred years ago, the opinions of men in natural philosophy were as various and as contradictory as they are now concerning the powers of the mind. Galileo, Torricelli, Kepler, Bacon, and Newton, had the same discouragement in their attempts to throw light upon the material system, as we have with regard to the intellectual. If they had been deterred by such prejudices, we should never have reaped the benefit of their discoveries, which do honour to human nature, and will make their names immortal. The motto which Lord Bacon prefixed to some of his writings was worthy of his genius, Inveniam viam aut faciam.*

There is a natural order in the progress of the sciences, and good reasons may be assigned why the philosophy of body should [5] be elder sisler to that of mind, and of a quicker growth ; but the last hath the principle of life no less than the first, and will grow up, though slowly, to maturity. The remains of ancient philosophy upon this subject, are venerable ruins, carrying the marks of genius and industry, sufficient to inflame, but not to satisfy our curiosity. In later ages, Des Cartes was the first that pointed out the road we ought to take in those dark regions. Malebranche, Arnauld, Locke, Berkeley, Buffier, Hutcheson, Butler, Hume, Price, Lord Karnes, have laboured to make discoveries — nor have they laboured in vain; for, however different and contrary their conclusions are, however sceptical some of them, they have all given new light, and cleared the way to those who shall come after them.

We ought never to despair of human genius, but rather to hope that, in time, it may produce a system of the powers and operations of the human mind, no less certain than those of optics or astronomy.

This is the more devoutly to be wished, that a distinct knowledge of the powers of the mind would undoubtedly give great light to many other branches of science. Mr Hume hath justly observed, that " all the

• See Mr Stewart's " Philosophical Essays," Preliminary Disseitation, ch. ii

PREFACE.

sciences have a relation to human nature ; and, however wide any of them may seem to run from it, they still return hack hy one passage or another. This is the centre and capital of the sciences,* which, being once masters of, we may easily extend our conquests everywhere."

The faculties of our minds are the tools and engines we must use in every disquisition ; and the better we understand their [6] nature and force, the more successfully we shall he able to apply them. Mr Locke gives this account of the occasion of his entering upon his essay concerning human understanding : — " Five or six friends," says he, " meeting at my chamber, and discoursing on a subject very remote from this, found themselves quickly at a stand by the difficulties that rose on every side. After we had for a while puzzled ourselves, without coming any nearer to a resolution of those doubts that perplexed us, it came into my thoughts that we took a wrong course ; and that, before we set ourselves upon inquiries of that nature, it was necessary to examine our own abilities, and see what objects our understandings were fitted or not fitted to deal with. This I proposed to the company, who all readily assented ; and thereupon it was agreed that this should be our first enquiry.'' If this be commonly the cause of perplexity in those disquisitions which have least relation to the mind, it must be so much more in those that have an immediate connection with it.

The sciences may be distinguished into two classes, according as they pertain to the material or to the intellectual world. The various parts of natural philosophy, the mechanical arts, chemistry, medicine, and agriculture, belong to the first ; but, to the last, belong grammar, logic, rhetoric, na-

* Hume probably had the siying of Poljrbius in his eye, who calls History the mother city (/j^rtirt' Xis ) of Philosophy.— H.

tural theology, morals, jurisprudence, law. politics, and the fine arts. The knowledge of the human mind is the root from which these grow, and draw their nourishment.* Whether, therefore, we consider the dignity of this subject, or its subserviency to science in general, and to the noblest branches of science in particular, it highly deserves to be cultivated. [7]

A very elegant writer, on the sublime and beautiful ,-f- concludes his account of the passions thus : — " The variety of the passions is great, and worthy, in every branch of that variety, of the most diligent investigation. The more accurately we search into the human mind, the stronger traces we everywhere find of His wisdom who made it. If a discourse on the use of the parts of the body may be considered as a hymn to the Creator, X the use of the passions, which are the organs of the mind, cannot be barren of praise to Him, nor unproductive to ourselves of that noble and uncommon union of science and admiration, which a contemplation of the works of infinite Wisdom alone can afford to a rational mind ; whilst referring to Him whatever we find of right, or good, or fair, in ourselves, discovering His strength and wisdom even in our own weakness and imperfection, honouring them where we discover them clearly, and adoring their profundity where we are lost in our search, we may be inquisitive without impertinence, and elevated without pride ; we may be admitted, if I may dare to say so, into the counsels of the Almighty, by a consideration of his works. This elevation of the mind ought to be the principal end of all our studies, which, if they do not in some measure effect, they are of very little service to us."

* It is justly observed by M. Jouffroy, that the division here enounced is not in principle identical with that previrusly propounded. — H.

f Burke.— H.

J Galen is referred to — H.

i.r]

ESSAYS

ON THB

INTELLECTUAL POWERS OF MAN.

ESSAY I.

PRELIMINARY

CHAPTER I.

EXPLICATION OP WORDS.

There is no greater impediment to the advancement of knowledge than the ambiguity of words. To this chiefly it is owing that we find sects and parties in most branches of science ; and disputes which are carried on from age f o age, without being brought to an issue.

Sophistry has been more effectually excluded from mathematics and natural philosophy than from other sciences. In mathematics it had no place from the beginning ; mathematicians having had the wisdom to define accurately the terms they use, and to lay down, as axioms, the first principles on which their reasoning is grounded. Accordingly, we find no parties among mathematicians, and hardly any disputes.* [10]

In natural philosophy, there was no less sophistry, no less dispute and uncertainty, than in other sciences, until, about a century and a half ago, this science began to be built upon the foundation of clear definitions and self-evident axioms. Since that time, the science, as if watered with the dew of Heaven, hath grown apace ; disputes have ceased, truth hath prevailed, and the science hath received greater increase in two centuries than in two thousand years before.

It were to be wished that this method, which hath been so successful in those branches of science, were attempted in others ; for definitions and axioms are the foundations of all science. But that definitions may not be sought where no definition can be given, nor logical definitions be attempted where the subject does not admit of them, it may be proper to lay down some general principles concerning definition, for

* It was not the superior wisdom of mathematicians, but the simple and palpable character of their object-matter, which determined the difference.— H.

[9-11]

the sake of those who are less conversant in this branch of logic.

When one undertakes to explain any art or science, he will have occasion to use many words that are common to all who use the same language, and some that are peculiar to that art or science. Words of the last kind are called terms of the art, and ought to be distinctly explained, that their meaning may be understood.

A definition* is nothing else but an explication of the meaning of a word, by words whose meaning is already known. Hence it is evident that every word cannot be defined ; for the definition must consist of words ; and there could be no definition, if there were not words previously understood without definition. Common words, therefore, ought to be used in their common acceptation ; and, when they have different acceptations in common language, these, when it is necessary, ought to be distinguished. But they require no definition. It is sufficient to define words that are uncommon, or that are used in an uncommon meaning.

It may farther be observed, that there are many words, which, though they may need explication, cannot be logically defined. A [ 1 1 ] logical definition — that is, a strict and proper definition — must express the kind [genus] of the thing defined, and the specific difference by which the species defined is distinguished from every other species belonging to that kind. It is natural to the mind of man to class things under various kinds, and again to subdivide every kind into its various species. A species may often be subdivided into subordinate species, and then it is considered as a kind.

From what has been said of logical definition, it is evident, that no word can be logically defined which does not denote a

* In what follows, there is a confusion of definitions verbal and real, which should have been carefully distinguished. — H.

ON THE INTELLECTUAL POWERS.

£eS8AY I.

species ; because such things only can have a specific difference ; and a specific difference is essential to a logical definition. On this account there can be no logical definition of individual things, such as London or Paris. Individuals are distinguished either by proper names, or by accidental circumstances of time or place ; but they have no specific difference ; and, therefore, though they may be known by proper names, or may be described by circumstances or relations, they cannot be defined. * It is no less evident that the most general words cannot be logically defined, because there is not a more general term, of which they are a species.

Nay, we cannot define every species of things, because it happens sometimes that we have not words to express the specific difference. Thus, a scarlet colour is, no doubt, a species of colour ; but how shall we express the specific difference by which scarlet is distinguished from green or blue ? The difference of them is immediately perceived by the eye ; but we have not words to express it. These things we are taught by logic.

Without having recourse to the principles of logic, we may easily be satisfied that words cannot be defined, which signify things perfectly simple, and void of all composition. This observation, I think, was first made by Des Cartes, and afterwards more fully illustrated by Locke, -j- And, however obvious it appears to be, many instances may be given of great philosophers who have perplexed [12] and darkened the subjects they have treated, by not knowing, or not attending to it.

When men attempt to define things which cannot be defined, their definitions will always be either obscure or false. It was one of the capital defects of Aristotle's philosophy, that he pretended to define the simplest things, which neither can be, nor need to be defined — such as time and motivn.% Among modern philosophers, I

* It is well said by the old logicians, Omnis intuitiva notitia est definition — that is, a view of the thinj. itself is its best definition. \\\i *his is true, both of the objects of sense, and of the objects of selfconsciousness. — H.

t This is incorrect. Des Cartes has little, and Locke no title to praise for this observation. It had been made by Aristotle, and alter him by many others; while, subsequent to Des Cartes, and previovs to Locke, Pascal and the Poit- Royal Logicians, to say nothing of a paper of Leibnitz, in 1684, had reduced it to a matter of commonplace. In this instance, Locke can, indeed, be proved a borrower. Mr Stewart (" Philosophical Essays," Note A) is wrong in thinking that, after Des Cartes, Lord Stair is the earliest philosopher by whom this logical principle was enounced ; for Stair, as a writer, is subsequent to the authors adduced. — H.

% There is not a little, however, to be said in vindication of Aristotle's definitions. Leibnitz is not the only modern philosopher who has applauded that of Motion, which requires, however, some ilh stration of the special significance of its terms — H.

ri2, is]

know none that has abused definition so much as Carolus [Christianus] Wolfius, the famous German philosopher, who, in a work on the human mind, called a Psychologia Empirica," consisting of many hundred propositions, fortified by demonstrations, with a proportional accompaniment of definitions, corollaries, and scholia, has given so many definitions of things which cannot be defined, and so many demonstrations of things self-evident, that the greatest part of the work consists of tautology, and ringing changes upon words.*

There is no subject in which there is more frequent occasion to use words tha; cannot be logically defined, than in treating of the powers and operations of the mind. The simplest operations of our minds must all be expressed by words of this kind. No man can explain, by a logical definition, what it is to think, to apprehend, to believe, to will, to desire. Every man who understands the language, has some notion of the meaning of those words ; and every man who is capable of reflection may, by attending to the operations of his own mind, which are signified by them, form a clear and distinct notion of them ; but they cannot be logically defined.

Since, therefore, it is often impossible to define words which we must use on this subject, we must as much as possible use common words, in their common acceptation, pointing out their various senses where they are ambiguous ; and, when we are obliged to use words less common, we must endeavour to explain them [13] as well as we can, without affecting to give logical definitions, when the nature of the thing does not allow it.

The following observations on the meaning of certain words are intended to supply, as far as we can, the want of definitions, by preventing ambiguity or obscurity in the use of them.

1. By the mind of a man, we understand that in him which thinks, remembers, reasons, wills.-)- The essence both of body and of mind is unknown to us. We know certain properties of the first, and certain operations of the last, and by these only we can define or describe them. We define body to be that which is extended, solid, moveable, divisible. In like manner, we define mind to be that which thinks. We are concious that we think, and that we have a variety of thoughts of different kinds — such as seeing, hearing, remembering, deliberating, resolving, loving, hating, and many

* This judgment is not false ; but it is exaggerated — H.

t This corresponds to Aristotle's second definition of the soul, or that a posteriori. Vide supra, p. 203 a, note « — H.

EXPLICATION OF WORDS.

other kinds of thought — all which we are taught by nature to attribute to one internal principle ; and this principle of thought we call the mind or soul of a man.

2. By the operations* of the mind, we understand every mode of thinking of which we are conscious.

It deserves our notice, that the various modes of thinking have always, and in all languages, as far as we know, been called by the name of operations of the mind, or by names of the same import. To body we ascribe various properties, but not operations, properly so called : it is extended, divisible, moveable, inert ; it continues in any state in which it is put ; every change of its state is the effect of some force impressed upon it, and is exactly proportional to the force impressed, and in the precise direction of that force. These are the general properties of matter, and these are not operations ; on the contrary, they all imply its being a dead, inactive thing, which moves only as it is moved, and acts only by being acted upon.-t* [14]