Saul Kripke has claimed that there are necessary connections between material things and their material origins. The usual defences of such necessity of origin theses appeal to either a sufficiency of origin principle or a branching-times model of necessity. In this paper we offer a different defence. Our argument proceeds from more modest ‘independence principles’, which govern the processes by which material objects are produced. Independence principles are motivated, in turn, by appeal to a plausible metaphysical principle governing such processes, (...) their invulnerability to non-local prevention. We outline the new argument, and distinguish it from both of the usual defences. (shrink)

There is a long tradition in philosophy of using a priori methods to draw conclusions about what is possible and what is necessary, and often in turn to draw conclusions about matters of substantive metaphysics. Arguments like this typically have three steps: first an epistemic claim , from there to a modal claim , and from there to a metaphysical claim.