Thus, even if two theories instantiate a relation of the sort required by Nagel’s model, we should not speak of proper reduction, if as a matter of epistemic possibility the connection between the domains of the two theories remains too loose to support the materialist claims. Levine (1993) gives this an epistemological interpretation; Chalmers (1996) seems to suggest that the epistemic possibility of two concepts coming apart implies that there is a metaphysical possibility of the two propertie