complex into simple ideas, and of sending a man to his senses' for a knowledge of the simple. In fact, however, when he explained ideas of sense as derived from the qualities of body, he was explaining simple ideas by reference to that which, according to his own showing, is a complex idea. To say that, as Locke understood the derivation in question, the primary qualities are an actiov yevéσews to the ideas of secondary qualities, but not an actiOv yvwσews-that without our having ideas of them they cause those ideas of sense from which afterwards our ideas of the primary qualities are formed -is to suppose an order of reality other than the order of our sensitive experience, and thus to contradict Locke's fundamental doctrine that the genesis of ideas is to be found by observing their succession in our own breasts.' It is not thus that Locke himself escapes the difficulty. As we have seen, he supposes our ideas of sense to be from the beginning ideas of the qualities of bodies, and virtually justifies the supposition by sending the reader to his sense of touch for that idea of solidity in which, as he defines it, all the primary qualities are involved. That the sense in question does not really yield the idea is what Hume points out when he says that, 'though bodies are felt by means of their solidity, yet the feeling is quite a different thing from the solidity, nor have they the least resemblance to each other.' In other words, having come to suppose that there are solid bodies, we explain our feeling as due to their solidity; but we may not at once interpret feeling as the result of solidity, and treat solidity as itself a feeling. It was by allowing himself so to treat it that Locke disguised from himself the objection to his interpretation of feeling. Hume tears off the disguise, and in effect gives him the choice of being convicted either of reasoning in a circle or of explaining the simple idea by reference to the complex. The solidity, which is to explain feeling, can itself only be explained by reference to body. If body is only a complex of ideas of sense, in referring tactual feeling to it we are explaining a simple idea by reference to a compound one. If it is not, how is it to be defined except in the circular' way, which Locke in fact adopts when he makes body a texture of solid parts' and solidity a relation of bodies ?! 1 See above, paragraph 101. True rationale of Locke's doctrine. With Hume 231. This vicious circle' was nothing of which Locke need have been ashamed, if only he had understood and avowed its necessity. Body is to solidity and to the primary qualities in general simply as a substance to the relations that determine it; and the 'circle' in question merely represents the logical impossibility of defining a substance except by relations, and of defining these relations without presupposing a substance. It was only Locke's confusion of the order of logical correlation with the sequence of feelings in time, that laid him open to the charge of making body and the ideas of primary qualities, and again the latter ideas and those of secondary qualities, at once precede and follow each other. To avoid this confusion by recognising the logical order the order of intellectual fictions'-as that apart from which the sequence of feelings would be no order of knowable reality at all, would be of course impossible for one who took Locke's antithesis of thought and fact for granted. The time for that was not yet. A way of escape had first to be sought in a more strict adherence to Locke's identification of the sequence of feelings with the order of reality. Hence Hume's attempt, reversing Locke's derivation of ideas of sense from primary qualities of body, to derive what with Locke had been primary qualities, as compound impressions of sense, from simple impressions and to reduce body itself to a name not for any 'just and consistent idea,' but for a propensity to feign,' the gradual product of custom and imagination. The question by which the value of such derivation and reduction is to be tried is our old one, whether it is not a tacit conversion of the supposed original impressions into qualities of body that alone makes them seem to yield the result required of them. If the Fourth Book of the Treatise on Human Nature,' with its elimination of the idea of body, had come before the second, would not the plausibility of the account of mathematical ideas contained in the latter have disappeared? And conversely, if these ideas had been reduced to that which upon elimination of the idea of body they properly become, would not that 'propensity to feign,' which is to take the place of the excluded idea, be itself unaccountable? 232.After exclusion of colours, sounds, heat and cold, from the rank of external existences, there remains nothing which can afford us a just and consistent idea of body.' 6 Our Now, no one can 'exclude them from the rank of external What existences' more decisively than Hume. They are impres- then? sions, and all impressions are internal and perishing existences, and appear as such.' Nor does he shirk the consequence, that we have no 'just and consistent idea of body.' It is true that we cannot avoid a 'belief in its existence 'a belief which according to Hume consists in the supposition of a continued existence of objects when they no longer appear to the senses, and of their existence as distinct from the mind and perceptions;' in other words, as 'external to and independent of us.' This belief, however, as he shows, is not given by the senses. That we should feel the existence of an object to be continued when we no longer feel it, is a contradiction in terms; nor is it less so, that we should feel it to be distinct from the feeling. We cannot, then, have an impression of body; and, since we cannot have an idea which does not correspond to an impression or collection of impressions, it follows that we can have no idea of it. How the 'belief in its existence' is accounted for by Hume in the absence of any idea of it, is a question to be considered later. present concern is to know whether the idea of extension can hold its ground when the idea of body is excluded. 233. The first notion of space and extension,' he says, 'is derived solely from the senses of sight and feeling: nor is there anything but what is coloured or tangible that has parts disposed after such a manner as to convey the idea.' Now, there may be a meaning of 'derivation,' according to which no one would care to dispute the first clause of this sentence. Those who hold that really, i.e. for a consciousness to which the distinction between real and unreal is possible, there is no feeling except such as is determined by thought, are yet far from holding that the determination is arbitrary; that any and every feeling is potentially any and every conception. Of the feelings to which the visual and tactual nerves are organic, as they would be for a merely feeling consciousness, nothing, they hold, can be said; in that sense they are an aπepov; but for the thinking consciousness, or (which is the same) as they really are, these feelings do, while those to which other nerves are organic do not, form the specific possibility of the conception of space. Ac VOL. I. See below, paragraph 303, and foll. Can Space survive Body? Hume derives iden of it from sight and feeling. Signin cance with him of vation. cording to this meaning of the words, all must admit that 'the first notion of space and extension is derived from the senses of sight and feeling;' though it does not follow that a repeated or continued activity of either sense is necessary to the continued presence of the notion. With Hume, however, the derivation spoken of must mean that the notion of space is, to begin with, simply a visual or tactual feeling, and that such it remains, though with indefinite abatement and revival in the liveliness of the feeling, according to the amount of which it is called 'impression' or 'idea.' If we supposed him to mean, not that the notion of space was either a visual or tactual feeling indifferently, but that it was a compound result of both,' we should merely have to meet a further difficulty as to the possibility of such composition of such deri- feelings when their inward synthesis in a soul, and the outward in a body, have been alike excluded. In the next clause of the sentence, however, we find that for visual and tactual feelings there are quietly substituted coloured and tangible objects, having parts so disposed as to convey the idea of extension.' It is in the light of this latter clause that the uncritical reader interprets the former. He reads back the plausibility of the one into the other, and, having done so, finds the whole plausible. Now this plausibility of the latter clause arises from its implying a three-fold distinction-a distinction of colour or tangibility on the one side from the disposition of the parts on the other; a distinction of the colour, tangibility and disposition of parts alike from an object to which they belong; and a distinction of this object from the idea that it conveys. In other words, it supposes a negative answer to the three following questions :— -Is the idea of extension the same as that of colour or tangibility? Is it possible without reference to something other than a possible impression? Is the idea of extension itself extended? Yet to the two latter questions, according to Hume's express statements, the answer must be affirmative; nor can he avoid the affirmative answer to the first, to which he would properly be brought, except by equivocation. It means, in effect, that colour and space are the same, 234. The pièces justificatives for this assertion are not far to seek. Some of them have been adduced already. The idea of space, like every other idea, must be a 'copy of an 6 impression." To speak of a feeling in its fainter stage as an 'image' of what it was in its livelier stage may, indeed, seem a curious use of terms; but in this sense only, according to Hume's strict doctrine, can the idea of space be spoken of as an 'image' of anything at all. The impression from which it is derived, i.e. the feeling at its liveliest, cannot properly be so spoken of, for no impression is presented by the senses as the image of anything distinct, or external, or independent." If no impression is so presented, neither can any idea, which copies the impression, be so. It can involve no reference to anything which does not come and go with the impression. Accordingly no distinction is possible between space on the one hand, and either the impression or idea of it on the other. All impressions and ideas that can be said to be of extension must be themselves extended; and conversely, as Hume puts it, all the qualities of extension are extended. qualities of a perception.' It should follow that space is either a colour or feeling of touch. In the terms which Hume himself uses with reference to substance,' if it be perceived by the eyes, it must be colour; if by the ears, a sound; and so on, of the other senses.' As he expressly tells us that it is 'perceived by the eyes,' the conclusion is inevitable. and that feeling may be of space are parts 235. Hume does not attempt to reject the conclusion di- The parts rectly. He had too much eye to the appearance of consistency for that. But, in professing to admit it, he wholly of a peralters its significance. The passage in question must be ception. quoted at length. The table, which just now appears to me, is only a perception, and all its qualities are qualities of a perception. Now, the most obvious of all its qualities is extension. The perception consists of parts. These parts are so situated as to afford us the notion of distance and contiguity, of length, breadth, and thickness. The termination of these three dimensions is what we call figure. The figure is moveable, separable, and divisible. Mobility and separability are the distinguishing properties of extended objects. And, to cut short all disputes, the very idea of extension is copied from nothing but an impression, and consequently must perfectly agree to it. To say the idea of extension agrees to anything is to say it is extended.' Thus 'there are impressions and ideas that are really extended.'' |