The notion of reduction continues to play a key role in philosophy of mind and philosophy of cognitive science. Supporters of reductionism claim that psychological properties or explanations reduce to neural properties or explanations, while antireductionists claim that such reductions are not possible. In this book, I apply recent developments in philosophy of science, particularly the mechanistic explanation paradigm and the interventionist theory of causation, to reassess the traditional approaches to reduction in philosophy of mind. I then elaborate and defend a pluralistic framework for philosophy of mind, and show how reductionist ideas can be incorporated into it. This leads to a novel synthesis of pluralism and reductionism that I call pluralistic physicalism.