perceptions only that constitute the mind."9 Hume is the frankest, as well as the ablest representative of Sensism, but Mill, Dr. Bain, and all leading members of the school accept this doctrine as the inevitable outcome of their principles; and they are unanimously agreed that the mind is nothing more than a succession of conscious states.

Now, this being on all hands allowed, we contend that Sensationism stands disproved. We do not know in the whole history of Philosophy, nay we cannot even conceive of any confutation more complete and decided being made out against a metaphysical system, than the reductio ad absurdum exhibited in this deduction from the Empiricist assumptions. If the intuitionist or dogmatist were forced to admit such a doctrine as this, the eloquence and sarcasm of his opponents would be plentifully poured forth. The blind prejudice of men claiming to be scientific inquirers, who yet shut their eyes to an obviously fatal flaw in this their theory would be dwelt upon at length, and the familiar credo quia impossibile, misquoted from Tertullian, would be again reproduced as a felicitous description of the mental attitude of the spiritualist philosopher.

be

That the dissolution of the Ego into a procession or series of phenomena is a reductio ad absurdum of Sensism, will become evident to the impartial thinker on a little reflexion. The argument may be summarized in a syllogism: If the mind were but a succession of transient states, then judgment, reasoning, self-conscious reflexion, and rational memory would absolutely impossible; but this is not the case; therefore the mind is not merely such a series. Judgment requires the indivisible unity of the agent which compares the terms; reasoning cannot take place unless the premisses successively apprehended are combined by one and the same simple energy; lastly, self-conscious reflexion and rational memory evidently imply the persistence of an abiding subject which can juxtapose the past with the present. Two terms, or two propositions, each grasped either at the same or 9 Treatise of Human Nature, Pt. IV. sect. 6.

different times by separate intellects do not result in a new judgment. Nor is the excitation of similar thoughts first in one mind and then in another, an act of memory. For knowledge proper the indivisible unity and persisting identity of the faculty which apprehends the subject and predicate of the judgment are essential.10

The truth of our contention here will become more patent by a little consideration of any familiar mental operation. I have, for instance, just awoke from sleep. I remember that yesterday was Sunday, and I recall my rising, dressing, and various other actions which I performed in the forenoon. I am convinced that I who now lie reflecting on my bed am the same person who acted thus yesterday. For the last six or eight hours the continuity of my conscious states, so far as any psychological observation can teach me, has been completely broken, yet I am perfectly certain of my identity. How is this possible, if Self is nothing more than a succession of states? I reproduce images which I recognize as similar to those which I experienced yesterday. These representations are apprehended as numerically different but yet like in kind to the original impressions; the I, on the other hand, is unthinkable unless as the same on the two occasions. Reflexion on this simple psychological experience demonstrates the falsity of the Sensationalist Philosophy.

10 That the Sensist theory is incompatible with the existence of even the simplest forms of intellectual judgment has been clearly exhibited by Lotze. "Any comparison of two ideas, which ends by our finding their contents like or unlike, presupposes the absolutely indivisible unity of that which compares them; it must be one and the same thing which first forms the idea of a, and then that of b, and which at the same time is conscious of the nature and extent of the difference between them. Then again the various acts of comparing ideas and referring them to one another are themselves in turn reciprocally related; and this relation brings a new activity of comparison to consciousness, and so on our whole inner world of thoughts is built up, not as a mere collection of manifold ideas existing with or after one another, but as a work in which these individual members are held together and arranged by the relating activity of this single pervading principle. This is what we mean by the Unity of Consciousness, and it is this we regard as the sufficient ground for assuming an indivisible soul." (Metaphysics, § 242.)

Mill felt this difficulty. He saw that in rejecting the doctrine that the Ego is something more than a succession of states he was forced to accept "the paradox that something which ex hypothesi is but a series of feelings is aware of itself as a series."11 He however abandons the hopeless attempt to remove the "paradox," naively counselling us that "by far the wisest thing we can do is to accept the fact." The term "paradox" is here abused. Incredible absurdity is the phrase which would have precisely described the proposition that a series of feelings could be aware of themselves as a series. We must not deceive ourselves with words. What is a series? It is a succession of distinct events, or several separate events succeeding each other. The terms, a "thread of consciousness," and a "series" of mental states, seem to indicate a unity of some sort to which, loose though it be, the self of the Empiricist Psychology has no claim. The moment we attempt to accurately conceive what is meant by a mere succession of conscious states, we perceive that a conviction of personal identity, and a memory of past actions, such as each man's own experience assures him he is possessed of, is absolutely impossible to it.12

On the other hand, Mill is again wrong in representing his opponents as teaching that "the mind or Ego is something different from any series of feelings or possibilities of them," if by "different" is meant that the Ego is something separate, standing out of all relation to its states. The states are nothing but modifications of the Ego; and the true mind is the subject plus its states, or the subject present in its states. It is "an abiding existence with a series of feelings." 13 The ground for the possibility of selfconsciousness, just as for self-determination, lies in the 11 Exam. cxxii. ad fin.

12 As Mr. Courtney urges, "Such a series could never be summed." (Metaphysics of Mill, p. 70.) Similarly Professor Knight, "A succession of states of mind has no meaning except in relation to the substrate of self that underlies the succession, giving it coherence, identity, and intelligibility. The states are different, but the self -whose states they are--is the same." (Hume, p. 177.)

13 Dr. M'Cosh's Exam. of Mill, c. v.,

immateriality of the soul. No material being, no activity intrinsically dependent on a material organ, can know itself or act upon itself. Free volition and self-consciousness therefore are alike incompatible with Sensism; and positivists are only logical in denying or seeking to explain away the existence of these attributes.

Besides the idea of Self, there are certain other abstract notions of such philosophical importance, that a word or two here regarding their genesis will be advisable. The chief and the most disputed of those not already dealt with, are the conceptions of Substance and Accident, of Causality, of the Infinite, of Space, and of Time.

Substance. The origin of the concept of Being we have already indicated. All Being is divided into substance and accident; consequently, the ideas of substance and accident are merely ideas of particular kinds of Being. Substance is defined as that which exists per se, that which subsists in itself; accident, as that which inheres in another as in a subject of inhesion. The primary element, therefore, in the notion of substance is subsistence, not permanence amid change; though the latter feature is usually more prominently suggested to the mind. Motion, sphericity, redness, feelings, volitions, cannot exist by themselves —an accident must always pertain to a subject; consequently, since an infinite series of accidents inhering in each other is an absurdity, we must come at last to a something which exists per se.14 Substance, then, is conceived as a subsisting something that abides the same amid the change of its accidents.

14 For a full defence of the validity of the notion of substance we refer the reader to the volume on Metaphysics, Bk. II. c. i. Cf. also First Principles, pp. 250-255. Here, as elsewhere, the questions of genesis and validity so often confounded must be carefully distinguished. The origin of the idea lies in experience. Its first complete elaboration is a gradual process involving reiterated observation and comparison. But once the conceptions of Substance and Accident are thus reached, it is immediately perceived as a self-evident necessary truth, that accident must ultimately inhere in a substance. This axiom is not a generalization from experience, nor a product of association: it is a rational intuition.

This idea is a product of intellectual experience. Even very early in life I observe things around me subsisting in themselves, and I am conscious that I myself possess real independent existence. Further examination causes me to notice greater or lesser changes taking place both in external objects and in myself. As I begin to reflect, however, I become assured that this change is not annihilation, and that some constituent element must remain the same amid the variations. Internal consciousness manifests to me my own substantial sameness amid my transient mental states, and reflexion on the evidence afforded by my external senses enables me to perceive the necessity of such an enduring identity underlying the transitory qualities of material objects. The reflexion required is not of a very deliberate or laborious character. It is a spontaneous activity of the rational mind. The shape and temperature of the piece of wax in the child's hands, the position and colour of objects before his eyes vary from moment to moment, but the substantiality of the object reveals itself to his intellect. Although the ideas of accident and substance were first wrought out very slowly, in mature life the apprehension of a necessary enduring element amid the fluctuating phenomena is so easy and rapid, that it may fairly be described as an intellectual intuition.

Causality. The notion of causality is connected with that of substance, and can be attained only by rational free beings. Sensuous perception acquaints us with successive phenomena, but from this source alone we could not derive the idea of causation any more than that of substantiality. On the other hand, this concept is not an innate cognition, nor a subjective form of the mind. It is the result of intellectual experience, and it possesses real extra-mental validity. We may distinguish three elements or factors which normally co-operate in the formation of this idea.

(1) In our internal experience we are conscious of change among our mental states. In some cases of variation the order of succession seems casual, or we at least are unaware of the force which determines the