220. It would seem then that the predicate may, though the subject cannot, represent either a single quality, or a set of qualities which falls far short even of those common to the class, much more of those which characterise any individual. If I can think these apart, or have an idea of them, as the predicate of a proposition, why not (it may be asked) as the subject? It may be said, indeed, with truth, that it is a mistake to think of the subject as representing one idea and the predicate another; that the proposition as a whole represents one idea, in the sense of a conception of relation between attributes, and that at bottom this account of it is consistent with Locke’s definition of knowledge as a perception of relation between ‘ideas,’ since with him ‘ideas’ and ‘qualities’ are used interchangeably. [1] It is no less true, however, that the relation between attributes, which the proposition states, is a relation between them in an individual subject. It is the nature of the individuality of this subject, then, that is really in question. Must it, as Hume supposed, be ‘considered’ under other qualities than those to which the predicate relates? When the proposition only concerns the relation between certain qualities of a spherical figure, must the figure still be considered as of a certain colour and material? [1] See above, paragraph 17. As to the subject, he equivocates between singleness of feeling and individuality of conception. 221. The possibility of such a question being raised implies that the step has been already taken, which Hume ignored, from feeling to thought. His doctrine on the matter arises from that mental equivocation, of which the effects on Locke have been already noticed, [1] between the mere singleness of a feeling in time and the individuality of the object of thought as a complex of relations. If the impression is the single feeling which disappears with a turn of the head, and the idea a weaker impression, every idea must indeed be in one sense ‘individual,’ but in a sense that renders all predication impossible because it empties the idea of all content. Really, according to Hume’s doctrine of general names, it is individual in a sense which is the most remote opposite of this, as a multitude of ‘different resemblances and relations’ in ‘simplicity.’ It is just such an individual as Locke supposed to be found (so to speak) ready-made in nature, and from which he supposed the mind successively to abstract ideas less and less determinate. Such an object Hume, coming after Berkeley, could not regard in Locke’s fashion as a separate material existence outside consciousness. The idea with him is a ‘copy’ not of a thing but of an ‘impression,’ but to the impression he transfers all that individualization by qualities which Locke had ascribed to the substance found in nature; and from the impression again transfers it to the idea which ‘is but the weaker impression.’ Thus the singleness in time of the impression