Mental causation is the causation of physical effects by mental causes. The paradigm case of mental causation is the causation of someone’s bodily movement by a mental state or event of hers. The belief that mental causation exists is deeply rooted in common sense. It seems uncontroversial to say, for instance, that a sudden pain caused Jones to wince, or that Smith’s thirst caused him to have a drink. Nevertheless, explaining how the mind can have physical effects has proven a challenge for philosophers of mind. For physical effects already have physical causes, which threatens the claim that they also have mental causes. The problem is most pressing for positions according to which the mind is not itself physical. However, recent decades have also seen a debate over whether the view that the mind is physical can adequately explain mental causation.