Truthmaking and supervenience

Abstract

In his criticism of Armstrong's argument against nominalism, Parsons (1999) makes a crucial use of a notion of truthmaking in terms of weak supervenience which assumedly: (i) does not entail truthmaker essentialism, (ii) is neutral as to the issue of nominalism, and (iii) is useful in Armstrong's argument against Ryle. I will try to show that Parsons' notion is defective because it does not preserve the explanatory character of truthmakers. Besides, I argue that the natural reformulation of the notion in terms of strong supervenience fails in two respects: (i) it is not neutral as to the issue of nominalism and (ii) it does not preserve the explanatory character of truthmakers if it succeeds in avoiding truthmaker essentialism. As a corollary, Armstrong's truthmaker argument against nominalism is vindicated.