Abstract
This paper introduces the term "Hempel's Dilemma" to refer to the following challenge to any formulation of physicalism that appeals to the content of physics: if physical properties are those mentioned as such in current physics, then physicalism is probably false; but if they are those mentioned as such in a completed physics, then, since we have no idea what completed physics will look like, the resulting formulation of physicalism will lack content that is determinable by us now. It shows how the first horn of Hempel's Dilemma can be avoided. The key is an account of what is required for the acceptance of physicalism according to which to accept physicalism does not require assigning to physicalism a high probability, merely a higher probability than is assigned to any of its relevant rivals. This account of acceptance is shown to satisfy all the intuitive demands of the scientific realist, so that to be a physicalist is simply to be a scientific realist regarding physicalism.