Locke fails to distinguish between identity and mere unity.
74. The process of self-contradiction, by which a ‘creation of the mind’ finds its way into the real or given, must also appear in a contradictory conception of the real itself. Kept pure of all that Locke reckons intellectual fiction, it can be nothing but a simple chaos of individual units: only by the superinduction of relation can there be sameness, or continuity of existence, in the minutest of these for successive moments. Locke presents it arbitrarily under the conception of mere individuality or of continuity, according as its distinction from the work of the mind, or its intelligible content, happens to be before him. A like see-saw in his account of the individuality and generality of ideas has already been noticed. [1] In his discussion of identity the contradiction is partly disguised by a confusion between mere unity on the one hand, and sameness or unity in difference, on the other. Thus, after starting with an account of identity as belonging to ideas which are the same at different times, he goes on to speak of a thing as the same with itself, at a single instant. So, too, by the principium individuationis, he understands ‘existence itself, which determines a being of any sort to a particular time and place.’ As it is clear from the context that by the principium individuationis he meant the source of identity or sameness, it will follow that by ‘sameness’ he understood singleness of a thing in a single time and place. Whence then the plurality, without which ‘sameness’ is unmeaning? In fact, Locke, having excluded it in his definition, covertly brings it back again in his instance, which is that of ‘an atom, i.e. a continued body under one immutable superficies, existing in a determined time and place.’ This, ‘considered in any instant of its existence, is in that instant the same with itself.’ But it is so because—and, if we suppose the consideration of plurality of times excluded, only because—it is a ‘continued’ body, which implies, though its place be determined, that it exists in a plurality of parts of space. Either this plurality, or that of instants of its existence, must be recognised in contrast with the unity of body, if this unity is to become ‘sameness with itself.’ In adding that not only at the supposed instant is the atom the same, but ‘so must continue as long as its existence continues,’ Locke shows that he really thought of the identical body under a plurality of times ex parte post, if not ex parte ante.
[1] See above, paragraphs 43, and the following.
Feelings are the real, and do not admit of identity. How then can identity be real?
75. But how is this continuity, or sameness of existence in plurality of times or spaces, compatible with the constitution of ‘real existence’ by mere individua? The difficulty is the same, according to Locke’s premisses, whether the simple ideas by themselves are taken for the real individua, or whether each is taken to represent a single separate thing. In his chapter on identity he expressly says that ‘things whose existence is in succession’ do not admit of identity. Such, he adds, are motion and thought; ‘because, each perishing the moment it begins, they cannot exist in different times or in different places as permanent beings can at different times exist in distant places.’ (Book I. chap, xxvii. sec. 2.) What he here calls ‘thought’ clearly includes the passive consciousness in which alone, according to his strict doctrine, reality is given. So elsewhere (Book II. chap. vii. sec. 9), in accounting for the ‘simple idea of succession,’ he says generally that ‘if we look immediately into ourselves we shall find our ideas always, whilst we have any thought, passing in train, one going and another coming, without intermission.’ [1] No statement of the ‘perpetual flux’ of ideas, as each having a separate beginning and end, and ending in the very moment when it begins, can be stronger than the above. If ‘ideas’ of any sort, according to this account of them, are to constitute real existence, no sameness can be found in reality. It must indeed be a relation ‘invented by the mind.’
[1] It is true that in this place Locke distinguishes between the ‘suggestion by our senses’ of the idea of succession, and that which passes in our ‘minds,’ by which it is ‘more constantly offered us.’ But since, according to him, the idea of sensation must be ‘produced in the mind’ if there is to be any either sensation or idea at all (Book II. chap, ix. secs. 3 and 4), the distinction between the ‘suggestion by our senses’ and what passes in our minds’ cannot be maintained.
Yet it is from reality that the idea of it is derived.
76. This, it may be said, is just the conclusion that was wanted in order to make Locke’s doctrine of the particular relation of identity correspond with his general doctrine of the fictitiousness of relations. To complete the consistency, however, his whole account of the origin of the relation (or of the idea in which it consists) must be changed, since it supposes it to be derived from an observation of things or existence, which again is to suppose sameness to be in the things or to be real. This change made, philosophy would have to start anew with the problem of accounting for the origin of the fictitious idea. It would have to explain how it comes to pass that the mind, if its function consists solely in reproducing and combining given ideas, or again in ‘abstracting’ combined ideas from each other, should be able to invent a relation which is neither a given idea, nor a reproduction, combination, or abstract residuum of given ideas. This is the great problem which we shall find Hume attempting. Locke really never saw its necessity, because the dominion of language—a dominion which, as he did not recognise it, he had no need to account for—always, in spite of his assertion that simple ideas are the sole data of consciousness, held him to the belief in another datum of which ideas are the appearances, viz., a thing having identity, because the same with itself in the manifold times of its appearance. This datum, under various guises, but in each demonstrably, according to Locke’s showing, a ‘creation of thought,’ has met us in all the modes of his theory, as the condition of knowledge. As the ‘abstract idea’ of substance it renders ‘perishing’ ideas into qualities by which objects may be discerned. (Book II. chap. xi. sec. 1.) As the relative idea of cause, it makes them ‘affections’ to be accounted for. As the fiction of a universal, it is the condition of their mutual qualification as constituents of a whole. Finally, as the ‘superinduced’ relation of sameness, the direct negative of the perpetual beginning and ending of ‘ideas,’ it constitutes the ‘very being of things.’
Transition to Locke’s doctrine of essence.
77. ‘The very being of things,’ let it be noticed, according to what Locke reckoned their ‘real,’ as distinct from their ‘nominal,’ essence. The consideration of this distinction has been hitherto postponed; but the discussion of the relation of identity, as subsisting between the parts of a ‘continued body,’ brings us upon the doctrine of matter and its ‘primary qualities,’ which cannot be properly treated except in connection with the other doctrine (which Locke unhappily kept apart) of the two sorts of ‘essence.’ So far, it will be remembered, the ‘facts’ or given ideas, which we have found him unawares converting into theories or ‘invented’ ideas, have been those of the ‘secondary qualities of body.’ [1] It is these which are united into things or substances, having been already ‘found in them:’ it is from these that we ‘infer’ the relation of cause and effect, because as ‘vicissitudes of things’ or ‘affections of sense’ they presuppose it: it is these again which, as ‘received from without,’ testify the present existence of something, because in being so received they are already interpreted as ‘appearances of something.’ That the ‘thing,’ by reference to which these ideas are judged to be ‘real,’ ‘adequate,’ and ‘true’—or, in other words, become elements of a knowledge—is yet itself according to Locke’s doctrine of substance and relation a ‘fiction of thought,’ has been sufficiently shown. That it is so no less according to his doctrine of essence will also appear. The question will then be, whether by the same showing the ideas of body, of the self, and of God, can be other than fictions, and the way will be cleared for Hume’s philosophic adventure of accounting for them as such.