 I’ve learned a lot over the years from talking about Lewis’s philosophy with Wolfgang Schwarz. I trust his book (2009) is excellent on all these topics, but unfortunately it’s only out in German so far, which I don’t read. But a lot of important points are collected on his  blog,  which is listed under other internet resources. This entry draws heavily on Daniel Nolan’s excellent book David Lewis (2005). Without that book, section 7.5 of this entry wouldn’t exist, section 6.3 would be unintelligible, and every section would be worse. Much of the biographical information in the introduction is taken from Hájek (2008), supplemented by the information in the short biography that written by Stephanie Lewis (2015). Many people helpfully spotted typos and infelicities of expression in earlier versions of this entry. Thanks especially to Zachary Miller for many suggested improvements and revisions. The bibliography is based in large part on a bibliography provided to me by Stephanie Lewis.