A while back I wrote a post in which I took a Wittgensteinian line against Descartes' cogito ergo sum. I was never all that happy with parts of it, and finally got around to fixing it. I'm not going to repost it, but here's the link: Descartes Contra Wittgenstein. I took out some parts that were a bit sophomoric and added a little to give a better sense of what Descartes was on about. I wouldn't say the piece is now perfect, but it's a lot better than it was before.