Prevention, Independence, and Origin

In 'A New Route to the Necessity of Origin' (2004, henceforth 'NR'), we offered an argument for the thesis that there are necessary connections between material things and their material origins. Much of the philosophical interest lay in our claim that the argument did not depend on so-called sufficiency principles for crossworld identity. It has been the verdict of much recent work on the necessity of origin that valid arguments for the thesis require some such sufficiency principle as a premise but that such principles are deeply problematic.' Finding an argument free of such principles would advance both our understanding and the plausibility of that thesis. These claims are now the subject of a pair of insightful critiques by Teresa Robertson and Graeme Forbes (2006, henceforth 'RF') and by Ross Cameron and Sonia Roca (2006, henceforth 'CR'), and we welcome the opportunity to clarify and improve our account of the matter. The argument we offered comes in two parts. The first is a derivation of a model necessity of origin thesis for tables from what we called an independence principle for tables: