Counterfactuals is David Lewis' forceful presentation of and sustained argument for a particular view about propositions which express contrary to fact conditionals, including his famous defense of realism about possible worlds.

David Lewis (1941- 2001) was Professor of Philosophy at Princeton University. His publications include Convention (reissued by Blackwell 2002), On the Plurality of Worlds (reissued by Blackwell, 2000), Parts of Classes (1991), and of numerous articles in metaphysics and other areas. Many of his writings are available in his Collected Papers.