This book develops some of the most important themes of Sen's works over the last decade. He argues in a rich and subtle approach that we should be concerned with people's capabilities rather than their resources or welfare.

Liberty is an expanded edition of Isaiah Berlin's classic of liberalism, Four Essays on Liberty. Berlin's editor Henry Hardy has incorporated a fifth essay, as Berlin wished, and added further pieces on the same topic, so that Berlin's principal statements on liberty are available together for the first time. He also describes the gestation of the book and throws further biographical light on Berlin's preoccupation with liberty in appendices drawn from his unpublished writings.