A new route to the necessity of origin

Saul Kripke (1980, 112–4) has claimed that there are necessary connections between material things and their material origins. His presentation of such necessity of origin theses included two paradigmatic examples: that it is impossible for a particular table to have been constructed from any hunk of matter other than that from which it was actually constructed, or for a particular human being to have originated in gametes other than those in which he or she actually did. Necessity of origin theses (henceforth, simply ‘origin theses’) are now standard examples of so-called metaphysical necessities, though unlike many other examples, they posit necessary connections between distinct individuals. Despite their familiarity, the conceptual grounds of origin theses are less clear than is usually supposed. Kripke’s influential discussion provides only the briefest sketch of an argument. More explicit treatments have since been offered, but all of these turn out to be variations of just two strategies. J. L. Mackie and Penelope Mackie suggest that origin theses are grounded in a branching times model of necessity. Nathan Salmon, Colin McGinn, Graeme Forbes, and others suggest that such theses are grounded in a further principle, the sufficiency of origin. Both approaches depend on stronger assumptions than Kripke’s original presentation appeared to call for, assumptions strong enough to engender a measure of skepticism in the philosophical community. In this paper, we identify a third, overlooked approach to such theses, an argument from what we call independence principles. On this approach, origin theses are by-products of a more fundamental feature of the processes by which material objects are produced, their mutual independence. Independence principles are motivated, in turn, as a consequence of a plausible metaphysical