This book is the result of many years of thought and research, and has taken on several different shapes before reaching its final version. It started as a project based on (and soon took off beyond) my Ph.D. thesis, written between 1992 and 1995. My research on Plato's cosmology goes back somewhat further, and I am happy that, as this book is coming to fruition, my La noción de dios en el Timeo de Platón, originally published in Buenos Aires in 1991, is due to appear in its second edition for a Spanish-speaking readership. Proper acknowledgements were made in both those productions to scholars and institutions, in Argentina and in England, which contributed to my research then. But I would like here to thank David Sedley and Richard Sorabji for their keen criticism early on. I am also grateful to Christopher Shields and Raphael Woolf, who commented on different chapters of the book, and to the anonymous referees for Cambridge University Press for their helpful suggestions. It is my pleasure to thank, in addition, the National Endowment for the Humanities for generous financial support, and the Center for Human Values at Princeton University, which has allowed me to finalise the manuscript in optimal research conditions and in an excellent collegial environment.

Previous versions of sections of this book have appeared as follows: Chapter 2, Section II.2 is based on Carone (2004c); Chapter 3, Section III is based on Carone (1997); parts of Chapter 5, Section I are based on Carone (2000); Chapter 6 is based on Carone (2004a); parts of Chapter 7 are based on Carone (1993); and parts of Chapter 8 are based on Carone (1994).