Abstract

When the atomic theory was revived in the seventeenth century, the atomists faced a problem concerning the status of the laws of nature. On the face of it, the postulation of absolutely hard, rigid, and impenetrable atoms seems to entail the existence of natural necessities and impossibilities: Atoms A and B cannot interpenetrate, so atom A must push atom B when they collide. The properties of compound bodies are to be explained in terms of their “textures” (i.e., the arrangements of their constituent atoms) on the famous lock-and-key model. Once again, it looks as if we have a domain of natural necessities depending on the textures of compound bodies. But the atomists seem to think of the laws of nature as radically contingent, not the sorts of things that could in principle be known a priori. This article seeks to address this tension between what the atomists seem committed to by their matter theory (real necessary connections in nature) and what they in fact say (that all the laws are contingent). In my Atomism (1995) I sought to resolve the tension by appealing to a sharp distinction between the atomists’ metaphysics and their epistemology. On this interpretation, they remain committed to natural necessity, but insist that we can never do Natural Philosophy in the “high priori” manner, by discovering real essences and their necessary connections. Our sciences of nature must remain empirical. Since publication of Atomism, however, this possible solution of the problem has come to seem more doubtful. Reflection on the work of my three “dissenting voices” (Margaret Osler, Peter Anstey and Rae Langton) has forced a radical rethink, focussing on the problematic relation between the intrinsic properties of the atoms and their (dynamic) powers. If there is no discoverable intelligible connection between what the atom is in itself (its intrinsic properties) and what it does (its powers), then my earlier solution will turn out to be untenable.