PREPARATION of this book was made possible by my tenure of a British Academy Readership in the Humanities during 1982-4, and by a term's sabbatical leave from my college thereafter. Jonathan Adler supplied me with many perceptive comments on an earlier draft, and provoked me into making some drastic revisions of it. Ian Maclean enabled me to think how the various arguments of that draft might appear to many philosophers outside the analytical tradition, and I have tried to clarify the relevant passages accordingly. To both of these friends I owe a substantial debt of gratitude for the care with which they read the text and for the time they devoted to thinking about it. I only hope that the final version will not disappoint them too much. I am also grateful for the comments and criticisms offered by the Oxford University Press's reader, and by those attending various lectures, conferences, seminars, or classes (in about three dozen universities or institutes in Australia, China, Hungary, Italy, Netherlands, New Zealand, UK, USA, and USSR) at which I have read papers that included earlier drafts of parts of the book.
Almost all the text is published here for the first time. But some paragraphs of § 13 have appeared in Russian in Voprosi Filosofii, 2, 1980, pp. 143-56 and in Chinese in Philosophical Problems of Natural Sciences, 1, 1981, pp. 12-18. And some paragraphs of Chapter IV are about to appear in the published proceedings of the 7th International Congress for Logic, Methodology, and Philosophy of Science. I am grateful to the editors concerned for not objecting to my weaving this material into the text of the present book.
Pat Lloyd has typed and retyped and re-retyped my manuscript with the care, patience, and accuracy that characterize all her work.
Unless there are contextual reasons to suppose otherwise, the pronoun 'he' is to be understood in the text as meaning 'he or she', the pronoun 'him' as meaning 'him or her' and the pronoun 'his' as meaning 'his or her'.
The Queen's College Oxford 19 February 1985