The papers in this volume, except for the introduction, were all presented, in the order in which they are published here, to the annual conference of the Royal Institute of Philosophy, held at the University of Reading in September 1996. The conference organiser and the Royal Institute of Philosophy would like to thank the Humanities Research Board of the British Academy for a British Conference Grant which went towards the travelling expenses of our U.S. speakers. I should also like to thank Yvonne Stanford, for her invaluable secretarial help in preparing for the conference.