David Lewis Ned Hall David Lewis died on October 14 of last year, from complications due to dia- betes. He was 60 years old. A professor of philosophy at Princeton University, Lewis received his doctorate in philosophy from Harvard University in 1967, work- ing under Willard van Orman Quine. He took up a teaching position at UCLA before moving to Princeton in 1970, where he remained for the rest of his career. Lewis's work reached into every significant philosophical domain. Given this breadth, it is remarkable that all of this work was at least first-rate, and most of it better: Whereas the most accomplished of Lewis's peers could each typically cite but a small number of their essays that deserve to be called "classics," Lewis could cite dozens. Nor was his very best work confined to a narrow range of specialties. On the contrary, he wrote brilliant and seminal papers, and four books, in logic, meta- physics, epistemology, philosophy of mathematics, philosophy of science, philoso- phy of language, philosophy of mind, and other areas. It would be difficult to exag- gerate the impact of these contributions. In the curious currency of our profession, we typically pay one another respect by disputing each other's positions with as much force as we can muster, in the idealistic hope that in the fire of argument last- ing philosophical insights occasionally can be forged. Keeping this measure in mind, one need merely scan the best professional philosophical journals to see with what reverence Lewis is held. And one need only read a Lewis paper to see why his work will remain of such lasting value. There are the philosophical insights, thick on every page. There is the breathtaking ease with which he moves back and forth between close technical work and "big picture" considerations. There is the stunningly lucid prose-unlike too many other famous philosophers, Lewis will not continue to be talked about merely because we don't understand him. There is the deft use of the second person, which quickly makes you feel as though Lewis is talking directly to you, gently and inex- orably persuading you of the merits of his position. Not that persuasion was always forthcoming. Much (though by no means all) of Lewis's work was controversial, albeit almost always in an agenda-setting way. Consider On the Plurality of Worlds, which is perhaps Lewis's most famous book and is the one in which he sets out and defends his notorious thesis that possibility is ontologically on a par with actuality. If, for example, I could have arisen earlier than I did this morning, that is because in another possible world-a world every bit a concrete as our own-a flesh-and-blood "counterpart" of me does in fact arise at the earlier time. Very few philosophers agree with this understanding of modality. Most, I suspect, either secretly or not-so-secretly consider it slightly mad. But after reading Lewis's book, none could dismiss it, as witness the myriad attempts in the subsequent literature to pinpoint exactly where Lewis's arguments go wrong. Moreover, in the course of his defense of the thesis, Lewis presents such an aston- X 2002 THE WARD REV~EW OF PHILOSOPHY 81