  Some historians (e.g., Matson 1966; King 2007) say the mind-body problem is relatively recent, the most important source being Descartes’s “real distinction” between mind and body. That said, you can find topics closely related to mental causation in, for example, Plato’s Phaedo and Aristotle’s De Anima, and it might turn out that many features of the contemporary debate are present in some form or other in pre-modern texts (Caston 1997). Skirting such historical questions, we begin with Descartes, who, for better or worse, set the agenda for modern discussions of mental causation. The cluster of causal problems arising from the Cartesian conception of mind is The Problem of Interaction.