The Nature of Possibility

I want to defend a Combinatorial theory of possibility. Such a view traces the very idea of possibility to the idea of the combinations – all the combinations which respect a certain simple form – of given, actual, elements. Combination is to be understood widely enough to cover the notions of expansion and contraction. (My central metaphysical hypothesis is that all there is is the world of space and time. It is this world which is to supply the actual elements for the totality of combinations. So what is proposed is a Naturalistic form of a combinatorial theory.) The combinatorial idea is not new, of course. Wittgenstein gave a classical exposition of it in the Tractatus. Perhaps its charter is 3.4: ‘A proposition determines a place in logical space. The existence of this logical place is guaranteed by the mere existence of the constituents’ (my italics). There is a small additional combinatorial literature. I myself was converted to a combinatorial view by Brian Skyrms’ brief but fascinating article ‘Tractarian Nominalism.’