Abstract

Sharon Lloyd's new book on Hobbes is one of the most significant in the last twenty-five years. She presents an original thesis about the foundation of Hobbes's moral philosophy, namely, that his basic moral principle is what she calls the "reciprocity theorem": "From our common definition of man as rational, Hobbes argues that we won't count a person as rational unless he can formulate and is willing to offer, at least post hoc, what he regards as justifying reasons for his conduct " . Three features of this explanation should be highlighted. The first is that she appreciates the role of definition in Hobbes's scientific moral philosophy; scientific propositions are theorems deduced from definitions. The second is that rationality is an important component of these deductions. The third, and the crucial one for her book, is that moral reasoning is essentially first-person reasoning. More needs to be said about the second and third features. I begin with the third