For myself I feel no such compulsion. When things are complex I recollect the several properties as cohering together, and when I abstract one or some for special consideration, I sometimes think of the others as forming a 'substance' in which the abstracted properties inhere. But I cannot discover any inherence or coherence except the mutual, and the notion of an invisible material setting which holds all the parts of a thing together seems to me superfluous and unwarranted. If it existed it would not be, as logicians argue, something superior and antithetical to phenomena; it would be simply an inferred or latent phenomenon like the luminiferous ether of science. The material substance is evidently a groping of the mind after the noumenal (mental) substance which causes the appearance of objects. XIV--NOMINALISM Nominalists deny the existence of general ideas as distinct from particular ideas. Most of them affirm that we employ general or common words to signify the common properties of similar things, but that we are incapable of thinking of these common properties apart from the other properties that accompany them. Why we should wish to use signs of things we cannot think about, or how a word can be a 'sign' when we are incapable of attaching a definite meaning to it, are points not satisfactorily cleared up by nominalists. Considering how well Berkeley's principle, combined with the plasmic theory, accounts for generalisation, and how inevitable it is that there should be general ideas distinguishable from particular ideas by superior brilliancy and endurance, it is surprising to find in Berkeley one of the most convinced and eloquent of nominalists. His views on the subject have so much weight with philosophers that I must examine them at length. 'It is agreed on all hands,' he writes in the Introduction to his _Principles_, 'that the qualities or modes of things do never really exist each of them apart by itself, and separated from all others, but are mixed, as it were, and blended together, several in the same object. But, we are told, the mind being able to consider each quality singly, or abstracted from those other qualities with which it is united, does by that means frame to itself abstract ideas. For example, there is perceived by sight an object extended, coloured, and moved: this mixed or compound idea the mind resolving into its simple constituent parts, and viewing each by itself, exclusive of the rest, does frame the abstract ideas of extension, colour, and motion. Not that it is possible for colour or motion to exist without extension; but only that the mind can frame to itself by _abstraction_ the idea of colour exclusive of extension, and of motion exclusive of both colour and extension.'