Emergence, Downwards Causation and the Completeness of Physics

The 'completeness of physics' is the key premise in the causal argument for physicalism. Standard formulations of it fail to rule out emergent downwards causation. I argue that it must do this if it is tare in a valid causal argument for physicalism. Drawing on the notion of conferring causal power, I formulate a suitable principle, 'strong completeness'. I investigate the metaphysical implications of distinguishing this principle from emergent downwards causation, and I argue that categoricalist accounts of properties are better equipped to sustain the distinction than dispositional essentialist accounts. Finally, I argue that the additional evidence needed for strong completeness renders the causal argument otiose for any properties amenable to scientific reduction.