[2] ‘Indifferently either abstract or confused,’ because of the conception that is most confused the least can be said; and it is thus most abstract.

Mathematical ideas, though ideas of ‘primary qualities of body,’ have ‘barely an ideal existence’.

112. From such a contradiction, even though he was not distinctly aware of it, he could not but seek a way of escape, From his point of view two ways might at first sight seem to be open—the priority in sensitive experience, and with it reality, might be assigned exclusively either to the idea of body or to that of space. To whichever of the two it is assigned, the other must become a nominal essence. If it is the idea of body that is conveyed to the mind directly from without through sensation, then it must be by a process in the mind that the spatial relations are abstracted from it; and conversely, if it is the latter that are given in sensation, it must be by a mental operation of compounding that the idea of body is obtained from them. Now, according to Locke’s fundamental notion, that the reality of an idea depends upon its being in consciousness a copy through impact of that which is not in consciousness, any attempt to retain it in the idea of space while sacrificing it in that of body would be obviously self-destructive. Nor, however we might re-write his account of the relations of space as ‘found in bodies,’ could we avoid speaking of them as relations of some sort; and if relations, then derived from the ‘mind’s carrying its view from one thing to another,’ and not ‘actually present sensations.’ We shall not, then, be surprised to find Locke tending to the other alternative, and gradually forgetting his assertion that ‘a circle or a square are the same whether in idea or in existence,’ and his elaborate maintenance of the ‘real existence’ of a vacuum, i.e., extension without body. (Book II. chap. xiii. secs. 21 and the following, and xvii. 4.) In the Fourth Book it is body alone that has real existence, an existence revealed by actually present sensation, while all mathematical ideas, the ideas of the circle and the square, have ‘barely an ideal existence’ (Book IV. chap. iv. sec. 6); and this means nothing else than the reduction of the primary qualities of body to a nominal essence. Our ideas of them are general (Book IV. chap. iii. sec. 24), or merely in the mind. ‘There is no individual parcel of matter, to which any of these qualities are so annexed as to be essential to it or inseparable from it.’ (Book III. chap. vi. sec. 6.) How should there be, when the ‘individual parcel’ means that which copies itself by impact in the present sensation, while the qualities in question are relations which cannot be so copied? Yet, except as attaching to such a parcel, they have no ‘real existence;’ and, conversely, the ‘body,’ from which they are inseparable, not being an individual parcel of matter in the above sense, must itself be unreal and belong merely to the mind. The ‘body’ which is real has for us no qualities, and that reference to it of the ‘actually present sensation’ by which such sensation is distinguished from other feeling, is a reference to something of which nothing can be said. It is a reference which cannot be stated in any proposition really true; and the difference which it constitutes between ‘bare vision’ and the feeling to which reality corresponds, must be either itself unreal or unintelligible.

Summary view of Locke’s difficulties in regard to the real.

113. We have now pursued the antithesis between reality and the work of the mind along all the lines which Locke indicates, and find that it everywhere eludes us. The distinction, which only appeared incidentally in the doctrine of substance, between ‘the being and the idea thereof—between substance as ‘found’ and substance as that which ‘we accustom ourselves to suppose’—becomes definite and explicit as that between real and nominal essence, but it does so only that the essence, which is merely real, may disappear. Whether we suppose it the quality of a mere sensation, as such, or of mere body, as such, we find that we are unawares defining it by relations which are themselves the work of the mind, and that after abstraction of these nothing remains to give the antithesis to the work of the mind any meaning. Meanwhile the attitude of thought, when it has cleared the antithesis of disguise, but has not yet found that each of the opposites derives itself from thought as much as the other, is so awkward and painful that an instinctive reluctance to make the clearance is not to be wondered at. Over against the world of knowledge, which is the work of the mind, stands a real world of which we can say nothing but that it is there, that it makes us aware of its presence in every sensation, while our interpretation of what it is, the system of relations which we read into it, is our own invention. The interpretation is not even to be called a shadow, for a shadow, however dim, still reflects the reality; it is an arbitrary fiction, and a fiction of which the possibility is as unaccountable as the inducement to make it. It is commonly presented as consisting in abstraction from the concrete. But the concrete, just so far as concrete, i.e., a complex world of relations, cannot be the real if the separation of the real from the work of the mind is to be maintained. It must itself be the work of the compounding mind, which must be supposed again in ‘abstraction’ to decompose what it has previously compounded. Now, it is of the essence of the doctrine in question that it denies all power of origination to the mind except in the way of compounding and abstracting given impressions. Its supposition is, that whatever precedes the work of composition and abstraction must be real [1] because the mind passively receives it: a supposition which, if the mind could originate, would not hold. How, then, does it come to pass that a ‘nominal essence,’ consisting of definite qualities, is constructed by a mind, which originates nothing, out of a ‘real’ matter, which, apart from such construction, has no qualities at all? And why, granted the construction, should the mind in ‘abstraction’ go through the Penelopean exercise of perpetually unweaving the web which it has just woven?

[1] ‘Simple ideas, since the mind can by no means make them to itself, must necessarily be the product of things operating on the mind.’ (Book IV. chap. v. sec. 4.)

Why they do not trouble him more.

114. It is Hume’s more logical version of Locke’s doctrine that first forces these questions to the front. In Locke himself they are kept back by inconsistencies, which we have already dwelt upon. For the real, absolutely void of intelligible qualities, because these are relative to the mind, he is perpetually substituting a real constituted by such qualities, only with a complexity which we cannot exhaust. By so doing, though at the cost of sacrificing the opposition between the real and the mental, he avoids the necessity of admitting that the system of the sciences is a mere language, well-or ill-constructed, but unaccountably and without reference to things. Finally, he so far forgets the opposition altogether as to find the reality of ‘moral and mathematical’ knowledge in their ‘bare ideality’ itself. (Book IV. chap. iv. sec. 6, &c.) Thus with him the divorce between knowledge and reality is never complete, and sometimes they appear in perfect fusion. A consideration of his doctrine of propositions will show finally how the case between them stands, as he left it.

They re-appear in his doctrine of propositions.

115. In the Fourth Book of the Essay the same ground has to be thrice traversed under the several titles of ‘knowledge,’ ‘truth,’ and ‘propositions.’ Knowledge being the perception of agreement or disagreement between ideas, the proposition is the putting together or separation of words, as the signs of ideas, in affirmative or negative sentences (Book IV. chap. v. sec. 5), and truth—the expression of certainty [1]—consists in the correspondence between the conjunction or separation of the signs and the agreement or disagreement of the ideas. (Book IV. chap. v. sec. 2.) Thus, the question between the real and the mental affects all these. Does this or that perception of agreement between ideas represent an agreement in real existence? Is its certainty a real certainty? Does such or such a proposition, being a correct expression of an agreement between ideas, also through this express an agreement between things? Is its truth real, or merely verbal?