Abstract

Physicalism should be characterized in a way that makes it compatible with the possibility that the physical world is infinitely decomposable. Some have proposed solving this problem by replacing a widely accepted No Fundamental Mentality requirement on physicalism with a more general No Low-Level Mentality requirement. The latter states that physicalism could be true if there is a level of decomposition beneath which nothing is mental, whereas physicalism is false otherwise. Brown argues that this solution does not work. He devises an infinitely decomposable possible world in which physicalism should come out as true even though there is mentality all the way down. I propose a solution that circumvents his argument. The key is to specify the sort of mentality that physicalism cannot abide at any level, namely, mentality that does not consist solely in a structural-dynamic arrangement of entities. I also argue that the problem Brown identifies has significant implications for what is at stake in the debate over physicalism’s truth or falsity—implications he undersells.