This book is an empirically informed investigation of the philosophical problem of mental causation, and a philosophical investigation of the status of cognitive scientific generalisations. If there are mental causes which can be classified in a way useful for predicting and explaining, then they are natural kinds. First. we develop an account of natural kinds that accommodates the cognitive. Second, we show how statements using these are not reducible to statements about physical kinds, involving biological and social facts. Finally, Virtual Machine Functionalism is defended as the correct account of the relationship between cognition and the material world.