Is there such a thing as mental causation? Is it possible for the mental to have causal influence on the physical? Or has the old “mind over matter” question been rendered obsolete by the advent of brain science? Whatever our answers to these questions, it seems that we cannot systematically pursue them without considering what makes mental causation problematic in the first place: The causal closure of the physical world. This paper revisits the problem of mental causation by drawing on (...) a classical debate between Dharmakirti and the Indian materialists. The main argument of the paper is that expanding our conception of causality to accommodate phenomenal content can cast new light on the problem of mental causation. A satisfactory solution to the problem of mental causation must reject the completeness of the physical principle in favor of conceptions of causality that allow for phenomenal properties to play a causal-explanatory function. (shrink)