invented an artificial one. He thinks that the signs which are naturally expressive of man's thoughts may be reduced to three kinds-modulations of the voice, gestures, and features. His explanation of this subject is interesting and instructive.S

Reid's doctrine of signs is connected with his view of perception. He distinguished perception from sensation, and stated that the simplest operations of the mind do not admit of logical definition. He often states that the sensations are merely signs, and that the objects themselves are the things signified; but he does not maintain that the sign resembles the original. He observes that the same mode of expression is used to denote sensation and perception, but sensation has more of the element of feeling in it than perception : mere sensation consists in its being felt and in nothing else; when it is not felt, it is not. Thus a sensation of pain signifies no more than the feeling of pain: the agreeable odour of a rose considered by itself is a pure sensation, which affects the mind in a certain way; and this affection of the mind may be conceived, without any thought of the rose. This doctrine, according to Reid, is applicable to every other mere sensation.4

On the other hand, perception, as understood by Reid, has always an external object, or an object distinct from the act by which it is perceived an object which may exist whether it be perceived or not. He maintained that we have an immediate perception, a direct intuition of the primary qualities of bodies. Our senses give us a direct and distinct notion of these qualities, as to what they are in themselves; but of the secondary qualities of bodies, our senses give us only a relative and obscure notion.

An act of perception of an external object he thus describes :- -(1) "We have some conception or notion of the object perceived; (2) a strong and irresistible conviction and belief of its present existence; (3) that this conviction and belief are immediate, and not the effect of reasoning." He also distinguishes perceptions into two classesthose which are original, and those which are acquired by experience.5

Thus Reid's doctrine of perception seems to be explicit. It has to be observed, however, that in his accounts of the views of other philosophers, and in his criticisms on them, he did not search out the

3 Hamilton's Reid, Vol. I., pp. 95-96, 117-118, et seq.

Ibid., Vol. I., p. 182, et seq.; and in Essays on the Intellectual Powers, Ibid., Vol. I., pp. 313 314, 258.

p. 310.

various theories of representative or mediate perception. This lack of exhaustive discrimination unintentionally led him into some mistakes which partially vitiated his criticisms of the doctrines of other philosophers, and rendered even the cardinal point of his own doctrine doubtful; for some hold that he is an idealist, and others that he is a realist. A brief explanation of this seems to be requisite.

1. First, then, some philosophers admit an immediate knowledge of a not-ego, but not of an external not-ego; while they do not limit the immediate knowledge of the mind to its own states, yet conceiving it impossible that the external reality can be brought within the sphere of consciousness, they suppose that it is represented by an image, numerically different from the mind, but placed somewhere, either in the brain or mind, within the sphere of consciousness. 2. Others deny to the mind any consciousness of a not-ego at all, and hold that what the mind immediately perceives, and mistakes for an external object, is merely the ego itself peculiarly modified. Each of these chief theories of a representative perception, admits of several subordinate varieties.

Thus, taking the first of the above hypotheses, it is subdivided according as the immediate object of perception is viewed-(1) as material, (2) as immaterial, (3) or as neither, (4) or as both, as something physical, as propagated from the external object, as generated in the medium or as fabricated in the mind itself; and the latter either in the intelligent mind or in the animal life, as infused by God or by angels, or as identical with the divine substance-as in the system of Spinoza, and in other pantheistic theories. In the second, the representative modification has been sometimes viewed as a mere product of the mind itself; or as innate, and so independent of any mental energy."

Now Reid never adequately distinguished these views of representative perception, either in their historical relation or as possible in theory, but directed his attacks against what he usually calls the common theory of ideas," which was merely one of the cruder forms of the representative theory of perception; and thus it happens. that his onslaughts on Berkeley and Hume are often misdirected and ineffective, as he did not establish the fact of the two cognitions, the

6 Hamilton's Reid, Vol. II., pp. 816-819; Lectures on Metp., Vol. II., pp.

presentative and the representative, single out their contents or evolve their conditions; and, in particular, did not show which of these was the kind of cognition competent in our perception of the external world. He failed to observe that representation is possible under two forms-the egoistical and the non-egoistical; and each of which, if perception be reduced to a representative faculty, affords premises equally available to the absolute idealist and the sceptic. Hence he was led into various inconsistences of a historical character, especially in the exposition of his own doctrine of perception.7

Yet, notwithstanding these defects of development and exposition, Reid performed good service to psychology by banishing the imaginary images interposed between perception and its objects.

Having indicated Reid's view of perception, I proceed to give a brief account of his treatment of the other phenomena of the mind. He divides the mental phenomena into the intellectual powers and the active powers; and he classified the intellectual powers thus :(1) The External Senses; (2) Memory; (3) Conception or Simple Apprehension; (4) Abstraction; (5) Judgment—First Truths; (6) Reasoning; (7) Taste. He distributed the active powers into three parts-I. Mechanical principles of actions (1) Instinct, (2) Habit; II. Animal principles (1) Appetites, (2) Desires, (3) Affections; III. Rational principles (1) Self-love, (2) Duty.8

9

Following the order just indicated, the first essay is devoted to an explication of terms and principles taken for granted. The second essay treats of the external senses, which we have already considered; in it also he reviews at great length the opinions of various philosophers touching the perception of the external world. He then passes to memory, which he treats at length, and affirms that it is an original faculty. He states that by memory we have an immediate knowledge of things in the past, and that it is always accompanied with the belief of that which we remember. Under the head of memory he discusses duration and personal identity. Of the latter he says:- "The conviction which every man has of his identity, as far back as his memory reaches, needs no aid of philosophy to strengthen it; and no philosophy can weaken it, without first producing some degree of insanity. indivisible, and is what Leibnitz calls a monad. tity of a person is a perfect identity; wherever it is real, it admits of no degrees, and it is impossible that a person should be in part

A

person

is something The iden

the same, and in part different; because a person is a monad, and is not divisible into

parts.

"10

He describes conception, and says that conceiving, imagining, apprehending, and understanding are words used to express that operation of the mind called simple apprehension; the having an idea of a thing is, in common language, used in the same sense. He refers to the train of thought in the mind, but he adduces nothing specially original on the association of thoughts and ideas, and in fact he was behind some of his predecessors in this important branch of mental science.

In his essay on abstraction, he explains general words, general conceptions, and the process of classification. Then, under the general heading of judgment, he discusses common sense and first principles. Common sense he regards as a special faculty, and the following quotation will indicate what Reid meant by this phrase:

"In common language, sense always implies judgment. A man of sense is a man of judgment. Nonsense is what is evidently contrary to right judgment. Common sense is that degree of judgment which is common to men with whom we can converse and transact business. Men rarely ask what common sense is; because every man believes himself possessed of it, and would take it for an imputation upon his understanding to be thought unacquainted with it.

"It is absurd to conceive that there can be any opposition between reason and common sense. It is indeed the first-born of reason, and as they are commonly joined together in speech and in writing, they are inseparable in their nature. We ascribe to reason two offices, or two degrees. The first is to judge of things self-evident; the second to draw conclusions that are not self-evident from those that are. The first of these is the province, and the sole province, of common

sense." 11

Thus Reid considered it the province of common sense to judge of first principles; and he further avers that, to judge of first prin

7 Hamilton's Reid, Vol. I., pp. 106, 128, 130, 131, 210, 226, 256, 257, 269, 274, 277, 293, 299, 318, 427.

8 This classification is not founded upon any essential principle of division of mental phenomena.

This is a mistake: we can only have a mediate knowledge of past things or events—that is, only a representative knowledge.

10 Hamilton's Reid, Vol. I. pp. 339-345.

11 Ibid., Vol. I., pp. 421-425.

ciples require no more than a sound mind free from prejudice and a clear conception of the question. The learned and the unlearned, the philosopher and the day-labourer, are upon a level, and will pass the same judgment, when they are not misled by some bias. He then proceeds to deliver his views of first principles.

Although first principles are self-evident, and cannot be proved by arguments, yet a certain kind of reasoning may be applied in their support:-1. To show that the principle rejected stands upon the same footing with others that are admitted. 2. As in mathematics, a reduction to absurdity may be employed. 3. The consent of ages and nations, of the learned and unlearned, ought to have great authority with regard to first principles, where every man is a competent judge. 4. Opinions that appear so early in the mind, that they cannot be the effect of education, or of false reasoning, have a good claim to be considered as first principles.

He asks whether the conclusions of common sense can be enumerated and digested in such a form as all reasonable men will assent to it. He recognises the difficulties besetting this, and admits that his own enumeration is not perfectly satisfactory. His classification proceeds on the distinction between necessary and contingent truths, and may be summarised thus:

(A.) Principles of Contingent Truths:-1. Everything that I am conscious of exists. 12 The irresistible conviction of the reality of what we are conscious of is not the effect of reasoning; it is immediate and intuitive, and therefore a first principle. 2. The thoughts that I am conscious of are the thoughts of a being that I call myself, my mind, my person. 3. Those things did really happen that I distinctly remember. 4. Our own personal identity and continued existence, as far back as we remember anything distinctly. 5. Those things do really exist that we distinctly perceive by our senses, and are what we perceive them to be. 6. We have some degree of power over our actions and the determinations of our will. The origin of our idea of power is not easily assigned. Power is not an object of sense or consciousness. We see events as successive, but not the power whereby they are produced. We are conscious of the operations of our minds; but power is not an operation of the mind. It is evidently, however, implied in every act of volition, and in all deliberation and resolution. Likewise, when we approve or disap

12 Reid treats consciousness as a special faculty which cannot be defined.