Daniel Nolan discusses a range of important issues in current philosophical work on the nature of possible worlds, general questions about metaphysical analysis and the direction of dependence between what is necessary and what could be.

David Lewis's work is of fundamental importance in many areas of philosophical inquiry and there are few areas of Anglo-American philosophy where his impact has not been felt. Lewis's philosophy also has a rare unity: his views form a comprehensive philosophical system, answering a broad range of questions in metaphysics, philosophy of mind, philosophy of language, philosophy of action and many other areas. This breadth of Lewis's work, however, has meant that it is difficult to know where to start in Lewis's work and a casual reader may often miss some of the illuminating connections between...