Abstract
The crudest formulation of physicalism is simply the claim that everything is physical, and perhaps that is all physicalism ought to imply. But in fact a large number of distinct versions of physicalism are currently in play, with very different commitments and implications. There is no agreement about the detailed formulation of the doctrine, even though a majority of philosophers would claim to be physicalists, and a vast majority of them are physicalists of one sort or another. There are several reasons for this lack of agreement: deep and imponderable questions about realism and the legitimacy of a narrowly defined notion of reality, questions about the scope of the term “physical,” issues about explanation and reduction, and worries about the proper range of physicalism, particularly with respect to so‐called abstract objects such as numbers, sets, or properties. And while the traditional challenge of psychological dualism poses a live threat only to a few iconoclasts, the project of specifying a physicalism which plausibly integrates mind into the physical world remains unfinished, despite the huge number and diversity of attempts.