  Suppose Gus decides to illuminate the room and subsequently flips a switch, thereby turning on the light. In this case we have a cause that, if Davidson is right, could be given both a mental and a physical description, and an effect that has a physical description. If this means that the cause has a mental property (in virtue of which it satisfies a mental description) and a physical property (in virtue of which it satisfies a physical description), we are faced with a further question. Granting that the event with the mental property is the event with a physical property, why should we think that the mental property had anything at all to do with the event’s physical effect?  Davidson’s second two principles appear to block such relevance. If all causal relations are subsumed under strict laws, and if there are no strict psychophysical laws, then any instance of mind–body causation is subsumed only by physical laws. But then it looks as though only a mental event’s physical properties are relevant to what it causes. The mental properties (or mental types) are causally irrelevant (see, e.g., Stoutland 1980; Honderich 1982; Sosa 1984; a review of this literature is in McLaughlin 1989).