of this faculty to poetical imagination, it is no less obvious, that, as the poet is supplied with all his materials by experience, and as his province is limited to combine and modify things which really exist, so as to produce new wholes of his own; so every exertion which he thus makes of his powers, presupposes the exercise of abstraction in decomposing and separating actual combinations. And it was on this account that, in the chapter on conception, I was led to make a distinction between that faculty, which is evidently simple and uncompounded, and the power of imagination, which (at least in the sense in which I employ the word in these inquiries) is the result of a combination of various other

powers.

I have introduced these remarks, in order to point out a difference between the abstractions which are subservient to reasoning, and those which are subservient to imagination. And, if I am not mistaken, it is a distinction which has not been sufficiently attended to by some writers of eminence. In every instance in which imag ination is employed in forming new wholes, by decompounding and combining the perceptions of sense, it is evidently necessary that the poet or the painter should be able to state to himself the circumstances abstracted, as separate objects of conception. But this is by no means requisite in every case in which abstraction is subservient to the power of reasoning; for it frequently happens, that we can reason concerning one quality or property of an object abstracted from the rest, while, at the same time, we find it impossible to conceive it separately. Thus, I can reason concerning extension and figure, without any reference to color; although it may be doubted, if a person possessed of sight can make extension and figure steady objects of conception, without connecting with them one color or another. Nor is this always owing (as it is in the instance now mentioned) merely to the association of ideas; for there are cases, in which we can reason concerning things separately, which it is impossible for us to suppose any being so constituted as to conceive apart. Thus, we can reason concerning length, abstracted from any other dimension; although, surely, no understanding can make length, without breadth, an object of conception. And, by the way, this leads me to take notice of an error, which mathematical teachers are apt to commit, in explaining the first principles of geometry. By dwelling long on Euclid's first definitions, they lead the student to suppose that they relate to notions which are extremely mysterious; and to strain his powers in fruitless attempts to conceive, what cannot possibly be made an object of conception. If these definitions were omitted, or very slightly touched upon, and the attention at once directed to geometrical reasonings, the student would immediately perceive, that although the lines in the diagrams are really extended in two dimensions, yet that the demonstrations relate only to one of them; and that the human understanding has the faculty of reasoning concerning things separately, which are always presented to us, both by our powers

of perception and conception, in a state of union. Such abstractions, in truth, are familiar to the most illiterate of mankind; and it is in this very way that they are insensibly formed. When a tradesman speaks of the length of a room, in contradistinction to its breadth; or when he speaks of the distance between any two objects, he forms exactly the same abstraction which is referred to by Euclid in his second definition, and which most of his commentators have thought it necessary to illustrate by prolix metaphysical disquisitions.

I shall only observe farther with respect to the nature and province of this faculty of the mind, that notwithstanding its essential subserviency to every act of classification, yet it might have been exercised, although we had only been acquainted with one individual object. Although, for example, we had never seen but one rose, we might still have been able to attend to its color, without thinking of its other properties. This has led some philosophers to suppose, that another faculty besides abstraction, to which they have given the name of generalization, is necessary to account for the formation of genera and species; and they have endeavored to show, that although generalization without abstraction is impossible, yet that we might have been so formed as to be able to abstract without being capable of generalizing. The grounds of this opinion it is not necessary for me to examine, for any of the purposes which I have at present in view."

SECTION II.

Of the Objects of our Thoughts, when we employ general terms.

FROM the account which was given in a former chapter of the common theories of perception, it appears to have been a prevailing opinion among philosophers, that the qualities of external objects are perceived by means of images or species transmitted to the mind by the organs of sense; an opinion of which I already endeavored to trace the origin, from certain natural prejudices suggested by the

The words abstraction and generalization are commonly, but improperly, used as synonymous: and the same inaccuracy is frequently committed in speaking of abstract or general ideas, as if the two expressions were convertible. A person who had never seen but one rose (it has been already remarked) might yet have been able to consider its color apart from its other qualities; and therefore, (to express myself in conformity to common language) there may be such a thing as an idea which is at once abstract and particular. After having perceived this quality as belonging to a variety of individuals, we can consider it without reference to any of them, and thus form the notion of redness or whiteness in general, which may be called a general abstract idea. These words abstract and general, therefore, when applied to ideas, are as completely distinct from each other as any two words to be found in the language.

It is indeed true, that the formation of every general notion presupposes abstraction; but it is surely improper on this account, to call a general term an abstract term, or a general idea an abstract idea.

phenomena of the material world. The same train of thinking has led them to suppose that, in the case of all our other intellectual operations, there exist in the mind certain ideas distinct from the mind itself; and that these ideas are the objects about which our thoughts are employed. When I recollect, for example, the appearance of an absent friend, it is supposed that the immediate object of my thoughts is an idea of my friend, which I at first received by my senses, and which I have been enabled to retain in the mind by the faculty of memory. When I form to myself any imaginary combination by an effort of poetical invention, it is supposed, in like manner, that the parts which I combine, existed previously in the mind, and furnish the materials on which it is the province of imagination to operate. It is to Dr. Reid we owe the important remark, that all these notions are wholly hypothetical; that it is impossible to produce a shadow of evidence in support of them; and that, even although we were to admit their truth, they would not render the phenomena in question more intelligible. According to his principles, therefore, we have no ground for supposing, that, in any one operation of the mind, there exists in it an object distinct from the mind itself; and all the common expressions which involve such a supposition, are to be considered as unmeaning circumlocutions, which serve only to disguise from us the real history of the intellectual phenomena.*

* In order to prevent misapprehensions of Dr. Reid's meaning in his reasonings against the ideal theory, it may be necessary to explain, a little more fully than I have done in the text, in what sense he calls in question the existence of ideas; for the meaning which the word is employed to convey in popular discourse, differs widely from that which is annexed to it by the philosophers whose opinion he controverts. This explanation I shall give in his own words:

"In popular language, idea signifies the same thing as conception, apprehension, notion. To have an idea of any thing, is to conceive it. To have a distinct idea, is to conceive it distinctly. To have no idea of it, is not to conceive it at all. When the word idea is taken in this popular sense, no man can possibly doubt whether he has ideas.

"According to the philosophical meaning of the word idea, it does not signify that act of the mind which we call thought, or conception, but some object of thought. Of these objects of thought called ideas, different sects of philosophers have given very different accounts.

"Some have held them to be self-existent; others, to be in the divine mind; others, in our own minds; and others, in the brain, or sensorium."-p. 213.

"The Peripatetic system of species and phantasms, as well as the Platonic system of ideas, is grounded upon the principle, that in every kind of thought, there must be some object that really exists; in every operation of the mind, something to work upon. Whether this immediate object be called an idea with Plato, or a phantasm or species with Aristotle; whether it be eternal and uncreated, or produced by the impressions of external objects, is of no consequence in the present argument."-Ibid. p. 388.

So much is this opinion fixed in the minds of philosophers, that, I doubt not but it will appear to most, a very strange paradox, or rather a contradiction, that men should think without ideas. But this appearance of contradiction, arises from the ambiguity of the word idea. If the idea of a thing means only the thought of it, which is the most common meaning of the word, to think without ideas, is to think without thought; which is undoubtedly a contradiction. But an idea, according to the definition given of it by philosophers, is not thought, but an object of thought, which really exists, and is perceived, &c."—Ibid. p. 390.

"We are at a loss to know," says this excellent philosopher, "how we perceive distant objects; how we remember things past; how we imagine things that have no existence. Ideas in the mind seem to account for all these operations; they are all by the means of ideas reduced to one operation; to a kind of feeling, or immediate perception of things present, and in contact with the percipient; and feeling is an operation so familiar, that we think it needs no explanation, but may serve to explain other operations.

"But this feeling, or immediate perception, is as difficult to be comprehended, as the things which we pretend to explain by it. Two things may be in contact, without any feeling of perception; there must, therefore, be in the percipient, a power to feel, or to perceive. How this power is produced, and how it operates, is quite beyond the reach of our knowledge. As little can we know, whether this power must be limited to things present, and in contact with us. Neither can any man pretend to prove, that the Being who gave us the power to perceive things present, may not give us the power to perceive things distant, to remember things past, and to conceive things that never existed." (Essays on the Intellectual Powers, p. 214.

In another part of this work, Dr. Reid has occasion to trace the origin of the prejudice which has led philosophers to suppose, that in all the operations of the understanding, there must be an object of thought, which really exists while we think of it. His remarks on this subject, which are highly ingenious and satisfactory, are contained in his account of the different theories concerning conception. (Ibid. p. 378.)

As in all the ancient metaphysical systems it was taken for granted, (probably from the analogy of our external perceptions,) that every exertion of thought implies the existence of an object distinct from the thinking being; it naturally occurred, as a very curious question, What is the immediate object of our attention,

I have only to add, that when, in this work, I make use of the word idea in stating my own opinions, I employ it uniformly in the popular sense, and not in the philosophical sense, as now explained; it would be better, perhaps, to avoid it altogether; but I have found it difficult to do so, without adopting unusual modes of expression. I flatter myself that I have used it with due caution.

I don't know of any author who, prior to Dr. Reid, has expressed himself on this subject with so much justness and precision as Father Buffier in the following passage of his Treatise on First Truths.

"If we confine ourselves to what is intelligible in our observations on Ideas, we will say, they are nothing but mere modifications of the mind as a thinking being. They are called ideas with regard to the object represented; and perception, with regard to the faculty representing. It is manifest that our ideas, considered in this sense, are not more distinguished from our understanding than motion is from a body moved."-(p. 311, Eng. Trans.)

From the word representation, however, employed by Buffier in the above passage, it would appear that even he conceived the idea or notion of the mind to bear a resemblance to the external corresponding object. It is not improbable that his imagination was misled by some such analogy as that which occurred to Leibnitz, when he called the mind a living mirror of the universe; a mode of speaking still common among the German metaphysicians at the present day.

when we are engaged in any general speculation; or, in other words what is the nature of the idea corresponding to a general term? When I think of any particular object which I have formerly perceived, such as a particular friend, a particular tree, or a particular mountain, I can comprehend what is meant by a picture or representation of such objects: and therefore the explanation given by the ideal theory of that act of the mind which we formerly called conception, if not perfectly satisfactory, is at least not wholly unintelligible. But what account shall we give upon the principles of this theory, of the objects of my thoughts, when I employ the words friend, tree, mountain, as generic terms? For, that all the things I have ever perceived are individuals; and consequently, that the ideas denoted by general words, (if such ideas exist) are not copied from any originals that have fallen under my observation, is not only self-evident, but almost an identical proposition.

In answer to this question, the Platonists, and, at a still earlier period, the Pythagoreans taught, that although these universal ideas are not copied from any objects perceivable by sense, yet that they have an existence independent of the human mind, and are no more to be confounded with the understanding, of which they are the proper objects, than material things are to be confounded with our powers of external perception; that as all the individuals which compose a genus must possess something in common; and as it is in consequence of this that they belong to that genus, and are distinguishable by the same name, this common thing forms the essence of each, and is the object of the understanding, when we reason concerning the genus. They maintained also, that this common essence, notwithstanding its inseparable union with a multitude of different individuals, is in itself one, and indivisible.

On most of these points, the Philosophy of Aristotle seems to have coincided very nearly with that of Plato. The language, however, which these philosophers employed on this subject was different, and gave to their doctrines the appearance of a wider diversity than probably existed between their opinions. While Plato was led by his passion for the marvelous and the mysterious, to insist on the incomprehensible union of the same idea or essence, with a number of individuals, without multiplication or division;†

* In this very imperfect sketch of the opinions of the ancients concerning universals, I have substituted, instead of the word idea, the word essence, as better fitted to convey to a modern reader the true import of Plato's expressions. The word essentia is said to have been first employed by Cicero; and it was afterwards adopted by the schoolmen, in the same sense in which the Platonists used the word idea. See Dr. Reid's Essays on the Intellectual Powers, p. 473.

"The idea of a thing," says Plato, " is that which makes one of the many; which, preserving the unity and integrity of its own nature, runs through and mixes with things infinite in number; and yet, however multiform it may appear, is always the same: so that by it we find out and discriminate the thing, whatever shapes it may assume, and under whatever disguise it may conceal itself.”—Plato in Philebo; quoted by the Author of the Origin and Progress of Language, vol. i. p. 100, 2d edit.