§ 3. _The Unity of the Thing._—The problem we have to face is as follows: in what sense do we call any thing “one thing,” and what gives it its character as a unity? It is obvious that we may attack this question from either of two rather different points of view. We may ask either, why do we mark off just this portion of our environment from all the rest as a single thing among many things; or, again, how is the oneness which we predicate of any part of the environment so marked off compatible with the multiplicity of its properties? The question we propose to deal with in this section is the former of the two just propounded; the latter shall be dealt with next as the problem of substance and its qualities. What, then, do we mean by the unity which we ascribe to whatever we recognise as one thing among a multiplicity of others? We have, in a way, implicitly answered this question already by the result arrived at in our discussion of the character of the elements or constituents of the system of Reality. But whereas, in our former investigation, we started from the general notion of Reality as a systematic whole of experience, and went on to ask what character is imposed on the elements of such a system by their presence in it as its elements, we have now to raise the same question from the other side; starting with our everyday recognition of our environment as divided into things, we have to ask how far these things possess the character which must belong to the genuinely individual members of an individual whole of subordinate individuals.