Professor Nadler's research focuses on philosophy in the seventeenth century, particularly issues in metaphysics and epistemology, as well as conceptions of reason and happiness. He has written extensively on Descartes and Cartesianism (especially Malebranche and Arnauld), Spinoza and Leibniz. He also works on medieval and early modern Jewish philosophy. His recent publications include Spinoza's Ethics: An Introduction (Cambridge, 2006) and A Companion to Early Modern Philosophy (Blackwell, 2003). He is currently the editor of the Journal of the History of Philosophy. His most recent books are The Best of All Possible Worlds: A Story of Philosophers, God, and Evil (Farrar, Straus, & Giroux, 2008), and The Cambridge History of Jewish Philosophy: From Antiquity through the Seventeenth Century (2009), which he co-edited with Tamar Rudavsky.