Descartes's Moral Theory is clearly written and well structured. Marshall makes his arguments easy to follow and uses illustrative examples. He considers and amply cites the relevant Cartesian texts, and is so fair to the opposing point of view in cases of textual ambiguity that one can mount strong counterarguments simply on the basis of evidence Marshall himself provides in his notes.- Sarah Donahue (The Review of Metaphysics) Rene Descartes is an important but neglected moral philosopher. John Marshall's book is designed 'to introduce Descartes's moral thought to an anglophone audience' and he succeeds.(Ethics)