Hempel's Dilemma remains at the center of the problem of defining physicalism. In brief, the dilemma asks whether physicalism should be defined by appeal to current or future physics. If defined by current physics, physicalism is almost certainly false. If defined by an ideal future physics, then physicalism has little determinable content. Montero and Papineau have innovatively suggested that the dilemma may be avoided by defining physicalism structurally. While their definition is one among many definitions, it is significant in that-if successful-it would break the impasse for defining physicalism. I argue, however, that the structural definition fails because it counts metaphysical frameworks (crucially, versions of divine idealism) as "physicalist"-an unwelcome result for physicalists. This paper thus furthers the debate on the definition of physicalism and sheds light on the relationship between physicalism and idealism.
