A Treatise of Human Nature · David Hume
GENERAL INTRODUCTION TO VOL. I.
But it is not maintained: the testimony is to operation of permanent identical things. 66. In short, as we have seen the simple idea of sensation emerge from Locke’s inquiry as to the beginning of knowledge transformed into the judgment, ‘I have an idea different from other ideas which I did not make for myself,’ so now from the inquiry as to the correspondence between knowledge and reality it emerges as the consciousness of a thing now acting upon me, which has continued to exist since it acted on me before, and in which, as in a common cause, have existed together powers to affect me which have never affected me together. If in the one form the operation of thought in sense, the ‘creation of the understanding’ within the simple idea, is only latent or potential, in the other it is actual and explicit. The relations of substance and quality, of cause and effect, and of identity--all ‘inventions of the mind’--are necessarily involved in the immediate, spontaneous testimony of passive sense. Locke’s treatment of relations of cause and identity.
67. It will be noticed that it is upon the first of these, the relation of substance and quality, that our examination of Locke’s Essay has so far chiefly gathered. In this it follows the course taken by Locke himself. Of the idea of substance, _eo nomine_, he treats at large: of cause and identity (apart from the special question of personal identity) he says little. So, too, the ‘report of the senses’ is commonly exhibited as announcing the sensible qualities of a thing rather than the agency of a cause or continuity of existence. The difference, of course, is mainly verbal. Sensible qualities being, as Locke constantly insists, nothing but ‘powers to operate on our senses’ directly or indirectly, the substance or thing, as the source of these, takes the character of a cause. Again, as the sensible quality is supposed to be one and the same in manifold separate cases of being felt, it has identity in contrast with the variety of these cases, even as the thing has, on its part, in contrast with the variety of its qualities. Something, however, remains to be said of Locke’s treatment of the ideas of cause and identity in the short passages where he treats of them expressly. Here, too, we shall find the same contrast between the given and the invented, tacitly contradicted by an account of the given in terms of the invented.
That from which he derives idea of cause pre-supposes it. 68. The relation of cause and effect, according to Locke’s general statement as to relation, must be something ‘not contained in the real existence of things, but extraneous and superinduced.’ (Book II. chap. xxv. sec. 8.) It is a ‘complex idea,’ not belonging to things as they are in themselves, which the mind makes by its own act. (Book II. chap xii. secs. 1, 7, and chap. xxv. sec. 1.) Its origin, however, is thus described:--‘In the notice that our senses take of the constant vicissitude of things, we cannot but observe that several particular, both qualities and substances, begin to exist; and that they receive this their existence from the due application and operation of some other being. From this observation we get our ideas of cause and effect. That which produces any simple or complex idea we denote by the general name cause; and that which is produced, effect. Thus, finding that in that substance which we call wax, fluidity, which is a simple idea that was not in it before, is constantly produced by the application of a certain degree of heat, we call the simple idea of heat, in relation to fluidity in wax, the cause of it, and fluidity the effect.
So, also, finding that the substance, wood, which is a certain collection of simple ideas so-called, by the application of fire is turned into another substance called ashes, _i.e._ another complex idea, consisting of a collection of simple ideas, quite different from that complex idea which we call wood; we consider fire, in relation to ashes, as cause, and the ashes as effect.’ Here we find that the ‘given,’ upon which the relation of cause and effect is ‘superinduced’ or from which the ‘idea of it is got’ (to give Locke the benefit of both expressions), professedly, according to the first sentence of the passage quoted, involves the complex or derived idea of substance. The sentence, indeed, is a remarkable instance of the double refraction which arises from redundant phraseology. Our senses are supposed to ‘take notice of a constant vicissitude of things,’ or substances. Thereupon we observe, what is necessarily implied in this vicissitude, a beginning of existence in substances or their qualities, ‘received from the due application or operation of some other being.’ Thereupon we infer, what is simply another name for existence thus given and received, a relation of cause and effect. Thus not only does the _datum_ of the process of ‘invention’ in question, _i.e._ the observation of change in a thing, involve a _derived_ idea, but a derived idea which presupposes just this process of invention.
Rationale of this ‘petitio principii’. 69. Here again it is necessary to guard against the notion that Locke’s obvious _petitio principii_ might be avoided by a better statement without essential change in his doctrine of ideas. It is true that ‘a notice of the vicissitude of things’ includes that ‘invention of the understanding’ which it is supposed to suggest, but state the primary knowledge otherwise--reduce the vicissitude of things, as it ought to be reduced, in order to make Locke consistent, to the mere multiplicity of sensations--and the appearance of suggestion ceases. Change or ‘vicissitude’ is quite other than mere diversity. It is diversity relative to something which maintains an identity. This identity, which ulterior analysis may find in a ‘law of nature,’ Locke found in ‘things’ or ‘substances.’ By the same unconscious subreption, by which with him a sensible thing takes the place of sensation, ‘vicissitude of things’ takes the place of multiplicity of sensations, carrying with it the observation that the changed state of the thing is due to something else. The mere multiplicity of sensations could convey no such ‘observation,’ any more than the sight of counters in a row would convey the notion that one ‘received its existence’ from the other.
Only so far as the manifold appearances are referred, as its vicissitudes, to something which remains one, does any need of accounting for their diverse existence, or in consequence any observation of its derivation ‘from some other being,’ arise. Locke, it is true, after stating that it is upon a notice of the vicissitude of things that the observation in question rests, goes on to speak as if an _origination_ of substances, which is just the opposite of their vicissitude, might be observed; and the second instance of production which he gives--that of ashes upon the burning of wood--seems intended for an instance of the production of a substance, as distinct from the production of a quality. He is here, however, as he often does, using the term ‘substance’ loosely, for ‘a certain collection of simple ideas,’ without reference to the ‘substratum wherein they do subsist,’ which he would have admitted to be ultimately the same for the wood and for the ashes. The conception, indeed, of such a substratum, whether vaguely as ‘nature,’ or more precisely as a ‘real constitution of insensible parts’ (Book III. chap. iii. secs. 18, &c.), governed all his speculation, and rendered to him what he here calls _substance_ virtually a _mode_, and its production properly a ‘vicissitude.’ Relation of cause has to be put into sensitive experience in order to be got from it.
70. We thus find that it is only so far as simple ideas are referred to things--only so far as each in turn, to use Locke’s instance, is regarded as an appearance ‘in a substance which was not in it before’--that our sensitive experience, the supposed _datum_ of knowledge, is an experience of the vicissitudes of things; and again, that only as an experience of such vicissitude does it furnish the ‘observation from which we get our ideas of cause and effect.’ But the reference of a sensation to a sensible thing means its reference to a cause. In other words, the invented relation of cause and effect must be found in the primary experience in order that it may be got from it. [1] [1] Locke’s contradiction of himself in regard to this relation might be exhibited in a still more striking light by putting side by side with his account of it his account of the idea of power. The two are precisely similar, the idea of power being represented as got by a notice of the alteration of simple ideas in things without (Book II. chap. xxi. sec. 1), just as the idea of cause and effect is. Power, too, he expressly says, is a relation. Yet, although the idea of it, both as derived and as of a relation, ought to be complex, he reckons it a simple and original one, and by using it interchangeably with ‘sensible quality’ makes it a primary _datum_ of sense.
Origin of the idea of identity according to Locke. 71. The same holds of that other ‘product of the mind,’ the relation of identity. This ‘idea’ according to Locke, is formed when, ‘considering anything as existing at any determined time and place, we compare it with itself existing at another time.’ ‘In this consists identity,’ he adds, ‘when the ideas it is attributed to, vary not at all from what they were that moment wherein we consider their former existence, and to which we compare the present; for we never finding nor conceiving it possible that two things of the same kind should exist in the same place at the same time, we rightly conclude that whatever exists anywhere, at any time, excludes all of the same kind, and is there itself alone. When, therefore, we demand whether anything be the same or no? it refers always to something that existed such a time in such a place, which it was certain at that instant was the same with itself, and no other; from whence it follows that one thing cannot have two beginnings of existence, nor two things one beginning; it being impossible for two things of the same kind to be or exist in the same instant in the very same place, or one and the same thing in different places. That, therefore, that had one beginning, is the same thing; and that which had a different beginning in time and place from that is not the same, but diverse.’ He goes on to inquire about the _principium individuationis_, which he decides is ‘existence itself, which determines a being of any sort to a particular time and place, incommunicable to two beings of the same kind ... for being at that instant what it is and nothing else, it is the same, and so must continue as long as its existence is continued; for so long it will be the same, and no other.’ (Book II. chap, xxvii. secs. 1-3).
Relation of identity not to be distinguished from idea of it. 72. It is essential to bear in mind with regard to identity, as with regard to cause and effect, that no distinction according to Locke can legitimately be made between the relation and the idea of the relation. As to substance, it is true, he was driven in his controversy with Stillingfleet to distinguish between ‘the being and the idea thereof,’ but in dealing with relation he does not attempt any such violence to his proper system. Between the ‘idea’ as such and ‘being’ as such, his ‘new way of ideas,’ as Stillingfleet plaintively called it, left no fair room for distinction. In this indeed lay its permanent value for speculative thought. The distinction by which alone it could consistently seek to replace the old one, so as to meet the exigencies of language and knowledge, was that between simple ideas, as given and necessarily real, and the reproductions or combinations in which the mind may alter them. But since every relation implies a putting together of ideas, and is thus always, as Locke avows, a complex idea or the work of the mind, a distinction between its being and the idea thereof, in that sense of the distinction in which alone it can ever be consistently admitted by Locke, was clearly inadmissible. Thus in the passages before us the relation of identity is not explicitly treated as an original ‘being’ or ‘existence,’ It is an idea formed by the mind upon a certain ‘consideration of things’ being or existent. But on looking closely at Locke’s account, we find that it is only so far as it already belongs to, nay constitutes, the things, that it is formed upon consideration of them.
This ‘invented’ relation forms the ‘very being of things’. 73. When it is said that the idea of identity, or of any other relation, is formed upon consideration of things as existing in a certain way, this is naturally understood to mean--indeed, otherwise it is unmeaning--that the things are first _known_ as existing, and that afterwards the idea of the relation in question is formed. But according to Locke, as we have seen, [1] the first and simplest act of knowledge possible is the perception of identity between ideas. Either then the ‘things,’ upon consideration of which the idea of identity is formed, are not known at all, or the knowledge of them involves the very idea afterwards formed on consideration of them. Locke, having at whatever cost of self-contradiction to make his theory fit the exigencies of language, virtually adopts the latter alternative, though with an ambiguity of expression which makes a definite meaning difficult to elicit. We have, however, the positive statement to begin with, that the comparison in which the relation originates, is of a thing with itself as existing at another time. Again, the ‘ideas’ (used interchangeably with ‘things’), to which identity is attributed, ‘vary not at all from what they were at that moment wherein we consider their former existence.’
It is here clearly implied that ‘things’ or ‘ideas’ _exist_, _i.e._ are given to us in the spontaneous consciousness which we do not make, as each one and the same throughout a multiplicity of times. This, again, means that the relation of identity or sameness, _i.e._ unity of thing under multiplicity of appearance, belongs to or consists in the ‘very being’ of those given objects of consciousness, which are in Locke’s sense the real, and upon which according to him all relation is superinduced by an after-act of thought. So long as each such object ‘continues to exist,’ so long its ‘sameness with itself must continue,’ and this sameness is the complex idea, the relation, of identity. Just as before, following Locke’s lead, we found the simple idea, as the element of knowledge, become complex--a perceived identity of ideas; so now mere existence, the ‘very being of things’ (which with Locke is only another name for the simple idea), resolves itself into a relation, which it requires ‘consideration by the mind’ to constitute. [1] See above, paragraph 25. 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.’
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.
What Locke understood by essence. 80. The essence of a thing with Locke, in the only sense in which we can know or intelligibly speak of it, is the meaning of its name. This, again, is an ‘abstract or general idea,’ which means that it is an idea ‘separated from the circumstances of time and place, and any other ideas that may determine it to this or that particular existence. By this way of abstraction it is made capable of representing more individuals than one; each of which, having in it a conformity to that abstract idea, is (as we call it) of that sort.’ (Book III. chap. iii. sec. 6.) That which is given in immediate experience, as he proceeds to explain, is this or that ‘particular existence,’ Peter or James, Mary or Jane, such particular existence being already a complex idea. [1] That it should be so is indeed in direct contradiction to his doctrine of the primariness of the simple idea, but is necessary to his doctrine of abstraction. Some part of the complex idea (it is supposed)--less or more--we proceed to leave out. The minimum of subtraction would seem to be that of the ‘circumstances of time and place,’ in which the particular existence is given.
This is the ‘separation of ideas,’ first made, and alone suffices to constitute an ‘abstract idea,’ even though, as is the case with the idea of the sun, there is only one ‘particular substance’ to agree with it. (Book III. chap. vi. sec. 1.) In proportion as the particular substances compared are more various, the subtraction of ideas is larger, but, be it less or more, the remainder is the abstract idea, to which a name--_e.g._ man--is annexed, and to which as a ‘species’ or ‘standard’ other particular existences, on being ‘found to agree with it,’ may be referred, so as to be called by the same name. These ideas then, ‘tied together by a name,’ form the essence of each particular existence, to which the same name is applied (Book III. chap. iii. secs. 12 and the following.) Such essence, however, according to Locke, is ‘nominal,’ not ‘real.’ It is a complex--fuller or emptier--of ideas in us, which, though it is a ‘uniting medium between a general name and particular beings,’ [2] in no way represents the qualities of the latter. These, consisting in an ‘internal constitution of insensible parts,’ form the ‘real essence’ of the particular beings; an essence, however, of which we can know nothing. (Book III. chap. vi. sec. 21, and ix. sec. 12.) [1] Book III. chap, iii, sec. 7, at the end.
Text from Project Gutenberg, public domain in the United States.