In this short yet ambitious work, Philip Pettit offers a single, unified, and overarching theory of freedom. A puzzling topic, freedom extends from the individual and the metaphysical (i.e. free will) to the social and the political, yet a theory connecting these two realms has yet to be devised. In an elegant, accessible manner, Pettit presents a survey of available theories of freedom, then develops his own--one that manages to straddle the personal and political spheres. The view he develops--which includes the seemingly paradoxical notion that we are free to the extent that we are capable of being held responsible--will make this pioneering book highly important to a wide range of philosophers.