A lot of people have helped me with this book. I started working on Gassendi while writing a dissertation on his Objections and Counter-Objections to the Meditations, and I would like to thank my committee – Peter Klein, Tom Lennon, Pierre Pellegrin, and especially Martha Bolton – for their help and support. I wrote the bulk of this manuscript while I was a joint Fellow at Cal Tech and the Huntington Library, and I am grateful to both institutions (and the Mellon Foundation) for their generous financial support and for the lovely working atmosphere they provided. I would especially like to thank Fiona Cowie, Moti Feingold, and Roy Ritchie.

Portions of this book were presented at Dalhousie University, Simon Fraser University, the University of Florida, the University of Nebraska at Lincoln, the University of Virginia, the University of Pittsburgh, and Virginia Tech; and to the Cartesian Circle at UC Irvine, the History and Philosophy of Science Working Group at Cal Tech, the October 2001 meeting of the Midwest Seminar in the History of Philosophy, a joint meeting of the Midwest Seminar, the Centre d'Études Cartesiennes and the Centro Interdipartimentale di Studi su Descartes, and the Oxford Workshop in Early Modern Philosophy. I am grateful to all these audiences.

A number of people have provided helpful comments on the manuscript or portions thereof: Martha Bolton, Jed Buchwald, Andrew Chignell, Fiona Cowie, Jack Davidson, Raffaella De Rosa, Stewart Duncan, Moti Feingold, Dan Garber, Geoff Gorham, Alan Hajek, Chris Hitchcock, Michael Jacovides, Richard Kroll, Mike Le Boeff, Tom Lennon, Paul Lodge, Dominic Murphy, Steve Nadler, Alan Nelson, Margaret Osler, Pierre Pellegrin, Andrew Pyle, Don Rutherford, Jorge Secada, Ed Slowik, Martin Stone, and two anonymous referees for the Press.