opposing; the superfluity of the curious organization of plants and animals on his system, &c. His answers bring out nothing new. He repeats his attacks on abstract ideas, in the leading instances of Time, Space, and Motion; and combats the doctrine of mathematicians as to the Infinite Divisibility of lines.

He is strenuous in maintaining the existence of spirit apart from ideas; spirit is the support and substratum of ideas, and cannot be itself an idea. The supposition that spirit can be known after the manner of an idea, or sensation, is a root of scepticism. He considers the Deity the immediate cause of all our sensations, and that the theory of the world is simplified by reducing everything to his direct agency; while atheism is deprived of its greatest support-the independent existence of

matter.

All the ingenuity of a century and half, has failed to see a way out of the contradiction exposed by Berkeley; although he has not always guarded his own positions. It is to be regretted that he could not find some other name than idea, for expressing our object consciousness. In spite of all his attempts to distinguish ideas of sensation from the commonly understood ideas, he laboured under a heavy disadvantage in running counter to the associations of familiar language. He laid himself open to refutation by something more severe than a 'grin,' or a nicknameIdealist.

HUME. Hume is noted for having embraced the views of Berkeley, with the exception of that relating to a separate soul or spirit. He thus reduced all existence to perceptions and ideas.

Hume's philosophy is given at greatest length in the Treatise on Human Nature.' The application of his philosophical principles to Material Perception, is found in Part IV. His subsequent work, entitled, 'An Enquiry concerning Human Understanding,' is prefaced by a note, desiring that this work, and not the Treatise on Human Nature, may be taken as representing his philosophical sentiments and principles. On referring to the Enquiry,' we find that the handling of the doctrine of perception is compressed into one very short chapter (Sect. xii.), entitled, Of the Academical or Sceptical Philosophy.' It does not appear, however, that the author's views on this doctrine underwent any change; or that any injustice would be done to him by referring to the more expanded treatment of Perception in the Human Nature.' His fundamental views of the mind are the same in both treatises. His resolution of all our Intellectual elements into Impressions and Ideas, differing only in vividness or intensity; his thoroughgoing Nominalism; his repudiation of any nexus in Cause and Effect beyond mere experience of their conjunction; his explanation of Belief by the greater vividness of the object; his reference of the belief in nature's uniformity to Custom; his refusal to admit anything that cannot be referred to a primary impression on the mind through the senses,-are cardinal doctrines of his philosophy from first to last.

In the later work, his remarks on Perception are in the following strain:-Men are prompted by a strong instinct of their nature to suppose the very images, presented by their senses, to be the external objects; not to represent them. On the other hand, philosophy so-called teaches that nothing can be present to the mind but an image or perception, that the senses are only the inlets, and do not constitute immediate intercourse between the mind and external objects. Thus philosophy has obviously departed from the dictates of nature, and has been deprived of that support, while exposing itself to the cavils of the sceptic, who asks, how it is that the perceptions of the mind must needs be caused by external objects (different, though resembling), and not from some energy of the mind itself, or through some unknown spirit or other cause? Can there be anything more inexplicable than that body should operate upon mind, the two being so different, and even so contrary in their nature? It is a question of fact, whether the perceptions of the senses be produced by external objects resembling them. How shall this question be determined? By experience surely; but in such a matter experience must be silent. The mind has nothing present to it but the perceptions, and cannot reach any experience of their connexion with objects.

He then remarks on the distinction between the secondary and primary qualities, with a view of showing that, as regards the independent existence of their objects, the two classes are on the same level.

If we turn to the Treatise on Human Nature, we find the subject of Sense Perception handled with great fulness of detail (Part IV. Sect. 2). Hume argues that, by the senses, we cannot know either continued or distinct existence. He then enquires how we came by the belief in the continued existence of the objects of the senses, and ascribes it to the coherence and constancy of our impressions respecting them. He observes that the mind once set agoing in a particular track, has a tendency to go on, even when objects fail it; and, through this tendency, we transmute interrupted existence into continued existence. He accounts, on his general theory of belief (following vividness of impression) for our believing in this imagined continuity. Continued existence, when once recognized, easily conducts us to distinct or independent existence; both being equally grounded on imagination, and not on reality.

In Sect. v., he treats of the Immateriality of the Soul, in which he represents the question, 'Whether our perceptions inhere in a material or in an immaterial substance?' as one wholly devoid of meaning. We have no perfect idea of anything but a perception. A substance is entirely different from a perception. We have therefore no idea of a substance. The doctrine of the immateriality, simplicity, and indivisibility of a thinking substance is a true atheism, and will serve to justify all those sentiments for which Spinoza is so universally infamous.'

In the chapter (Sect. vi.) on Personal Identity, he denies the existence of self in the abstract; there is nothing to give us the impression of a perennial and invariable self. When I enter,' he says, 'most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure.' Mind is nothing but a bundle of conceptions, in a perpetual flux and movement. He goes on to explain by what tendencies of the mind the fiction of a pure, absolute self is set up, and what is the real nature of what we call 'personal identity.'

Such is a brief indication of the celebrated scepticism of Hume. It is, however, to be remarked of him, in contrast to Berkeley, that he often expresses himself as if his theory was at variance with the experience of mankind. As he was a man fond of literary effects, as well as of speculation, we do not always know when he is earnest; but he speaks as if the belief that fire warms and water refreshes, was the revolt of nature against his scepticism. It is no wonder that others have supposed him to deny both the existence of matter and the existence of mind, although, in point of fact, he denies neither, but only a certain theoretic mode of looking at and expressing the phenomena admitted by all. The outery against him and Berkeley proves that a rose under another name does not always smell as sweet.

REID. Reid reclaimed against Berkeley and Hume, on the

ground of what he called Common Sense. To what purpose,' he says, 'is it for philosophy to decide against common sense in this or in any other matter? The belief of a material world is older, and of more authority, than any principles of philosophy.' "That we have clear and distinct conceptions of extension, figure, and motion, and other attributes of body, which are neither sensations, nor like any sensation, is a fact of which we may be as certain as that we have sensations.' In general, it may be said, that Reid declaims, rather than reasons on the question; and Hamilton, who equally repudiates the ideal theory, and appeals to consciousness in favour of the prevailing opinion, finds Reid often at fault, often confused, and sometimes even contradictory.' In his edition of Reid (Note C, p. 820), Hamilton draws up two classes of statements on the part of Reid, pointing to two opposing doctrines, one called 'the doctrine of mediate perception,' which Hamilton disavows, and the other called immediate perception,' which Hamilton adopts.

The doctrine of mediate conception, or representative conception, is the most glaring form of the doctrine of the separate existence of matter; its self-contradictory character is exposed by no one more vigorously than by Hamilton. He finds Reid slipping into it, in saying that the primary qualities, Extension, &c., are suggested to us through the secondary: the secondary are the signs, on occasion of which we are made to 'conceive' the primary. But, says Hamilton, if the primary qualities are suggested conceptions, our knowledge of the external world is wholly

subjective or ideal. Equally unguarded is the expression that, if sensation be produced, the perception follows, even when there is no object.' So, to localize sensation (a pain in the toe, for instance) in the brain is conformable to mediate or representative perception. Reid's use of the terms notion' and 'conception' likewise favours the same view. Also, in calling imagination of the past an immediate knowledge, Reid is on dangerous ground: such immediate knowledge, applied to perception, is really a mediate knowledge. Again, the doctrine of Reid and Stewart, that perception of distant objects is possible, if sifted, leads to representationism. Once more, Reid's calling perception an inference is of the same tendency. Finally, he ought not to separate, as he does, our belief of an external world from our cognition of it.

On the other hand, Hamilton adduces statements conformable to Real or Immediate presentation. These chiefly consist in repeating the common opinion of mankind, that whatever is perceived exists. Mr. J. S. Mill, in opposition to Hamilton, maintains that Reid throughout adhered to the doctrine of Representation, or mediate perception, and quotes numerous passages, where he iterates the view that the sensations are merely signs, and that the objects themselves are the things signified. What he did not maintain was, that the sign resembled the original; which is a crude form of representative perception.

STEWART followed Reid so closely on the subject of Perception, that a separate account of his opinions is unnecessary. BROWN is noted for the virulence of his attack upon Reid's claims to have vindicated Common Sense against Idealism. The attack has been reviewed by Hamilton, who in his turn is reviewed by Mr. J. S. Mill. Mr. Mill's reading of Brown is that he is substantially at one with Reid. 'He (Brown) thought that certain sensations, irresistibly, and by a law of our nature, suggest, without any process of reasoning, and without the intervention of any tertium quid, the notion of something external, and an invincible belief in its real existence. Brown differed from Reid (and also from Hamilton) in denying an intuitive perception of the Primary Qualities of bodies.

HAMILTON. Hamilton has distinguished himself both as the historian and critic of the Theories of Perception, and as the propounder of a theory of his own, different alike from Berkeley and from Reid.

He has endeavoured to give an exhaustive classification of all the possible theories. [See Edition of Reid, Note C, and Lectures.]

As his scheme is a theoretical rather than a historical one, it comprehends doctrines that have probably never been held. The first great division is into Presentation and Representation; or into those that consider what is presented to the mind as the whole fact, and those that consider that there is some other fact not presented to the mind. The first class-the Presentationists-

is divided into the Natural Realists or Natural Dualists, who accept the common sense view that the object of perception is something material, extended, and external [Hamilton's own opinion], and the Idealists, who consider that nothing exists beyond ideas of the mind. He gives various refined subdivisions of this class, which must of course take in Berkeley and Hume. Hume's extreme doctrine, he calls (in the Lectures) Nihilism, and expressively describes it as 6 a consciousness of various bundles of baseless appearances.' The second great class—the Representationists-has many supposed varieties; but the main example of it is designated by the phrase 'Cosmothetic Idealism'; meaning that an External World is supposed apart from our mental perception, as the inconceivable and incomprehensible cause of that perception. The mental fact or perception is thus not ultimate, but vicarious, and intermediate, the means of suggesting or introducing something else. This view Hamilton, in common with Berkeley, Hume, and Ferrier, holds to be untenable, and absurd.

His own doctrine-Natural Realism-by which he proposes to vindicate the common sense view, and yet avoid the difficulties of the Representative scheme, contains the following allegations:

1. In the act of sensible perception, I am conscious of two things-of myself the perceiving subject, and of an external reality in relation with my sense as the object perceived.

2. I am conscious of knowing each not mediately in something else, as represented, but immediately, as existing.

3. The two are known together, but in mutual contrast; they are one in knowledge, but opposed in existence.

4. In their mutual relation, each is equally dependent, and equally independent.

5. We are percipient of nothing but what is in proximate contact, in immediate relation with our organs of sense; in short, with the rays of light on the retina (Reid, p. 814). From which it follows as an inference, that when different persons look at the sun, each sees a separate object.

In the hostile criticisms of Mr. Samuel Bailey, and Mr. Mill, this last position has been singled out as the author's greatest contradiction both of fact and of himself. It may be remarked, however, that in his more fundamental positions, there is an insurmountable contradiction. By his hypothesis of immediate perception, he has escaped the difficulties of the Representationist, to fall into others equally serious. If we are to interpret terms according to their meaning, how are we to reconcile immediate knowledge, and an external reality? A reality external to us must be removed from us, if by never so little interval; and it is impossible to understand how the mind can be cognizant of a thing detached from itself. Then, how can the two things be equally dependent and equally independent. This is admissible as an epigram, but must be resolvable by a double sense of the words. In no sense can we reconcile independent existence with the dependence necessary to knowledge.