Aristotle on Metaphysics(2004) - Bibotu.com

THE DEFENCE OF PNC 125But we may note that apparently Priest ignores these qualifications, anddoes so deliberately, because his primary aim here is to argue that PNC isnot obviously true, and that, if it is true at all, this has to be shown. If thisis indeed Priest’s primary aim, it is one which <strong>Aristotle</strong> wholly shares. Wewill see (in this chapter and Chapter 6) that <strong>Aristotle</strong> goes to great lengthto defend PNC. He does not at all think that PNC is obviously true.But there may also be a deeper point behind the need to add suchqualifications. If PNC is to be true, it must be understood to say not onlythat a property (e.g. redness or motion) cannot be both true of and not trueof a single thing, in a loose sense of ‘a single thing’. For the tomato is asingle thing in spite of the various times of its existence, and it can be bothred and not red; the shirt is a single thing in spite of its various patterns,and it can be both red and not red; the spinning-top is a single thing inspite of its various geometrical parts, and it can be both in motion and notin motion. Rather, if PNC is to be true, it must be understood to say thata property (e.g. redness or motion) cannot be both true of and not true of asingle thing, in a more strict sense of ‘single’ or ‘unitary’ thing. Forexample, if PNC is to be true of the spinning-top, it must be understoodto say that motion cannot at any particular time be both true of and nottrue of the very same aspect or part of the spinning-top, e.g. itscircumference or its axis.So <strong>Aristotle</strong>, like Plato, argues that, if we at all want to defend theproposition that PNC is true of things and of all things, we need toinvestigate with particular care various ways in which things may or maynot be unitary. This point is extremely important. For it suggests that hethinks that, if we at all want to defend that PNC is true of things and of allthings, we need to engage in metaphysics and to ask the question, ‘What isit for something, anything, to be a being, something that is?’ Indeed, inIV. 2 he argues that to investigate what it is for something, anything, to bea being, is to investigate what it is for something, anything, to be onething. In general this is because metaphysics is centrally concerned withthe individuation of things, i.e. with the question of what it is for a thingto be one or many; and to this issue belongs the examination of howthings may or may not be unitary. So the investigation into various ways inwhich things may or may not be unitary, which is also necessary in orderto defend PNC, belongs at the core of metaphysics.