A central part of my critique of the argument from causal powers examined in Chapter 2 was that it equivocates on ‘causal powers’, using that notion in both its extended and restricted senses. I claimed that this equivocation reflects a deep problem in this a priori argument for individualism, one that indicates a fundamental incompatibility in the claims that need to be true for any version of this argument to be sound. Less explicit in that chapter was my more general scepticism about the prospects for a priori arguments for individualism. In this chapter, I argue more directly for both the depth of the identified equivocation and this more general scepticism.

A PRIORI ARGUMENTS FOR INDIVIDUALISM

The intuition that causal powers occupy a special place in taxonomy and explanation was expressed in the argument from causal powers by the claim that sciences taxonomize by causal powers (global individualism). One reaction to my critique of the argument from causal powers that I have found common in discussion is to grant the basic points of the critique (e.g., concede that global individualism is false) but to suppose that there is some other, closely related argument from a premise about causal powers to individualism that is immune to the critique. The frequency of this reaction reflects the strength of the intuition that causal powers occupy a special place in scientific taxonomy and explanation.