I was reading this thread at Leiter's about the nature of philosophy (glad to see people thinking about that, but I wasn't too jazzed about any of the answers there), and a mention of David Lewis reminded me that I had always thought there was an interesting comparison between Lewis's modal realism and Deleuze's conception of the virtual (unfortunately, I'm not well-versed enough in either to make anything of that myself). So I thought, huh, let's see what Google has to say about "Deleuze virtual David Lewis". First result = a pdf of the fifth paper on this page, entitled "Deleuze and Lewis on the real, the virtual, and the possible". Bingo! Not only that, this paper turns out to be a chapter from this book, the full text of which is available in pdf form at that second link, along with a lot of related material. Now if I just had time to read it ...
Also, random link-following has revealed that another discussion of the a priori is taking place here. Check it out!
2 hours ago