Years ago I read and took some notes on various works by Hannah Arendt. In particular her classic Origins of Totalitarianism. It's a great book, although perhaps insufficiently Marxist and somewhat idiosyncratic in a few of its interpretations, so I posted those notes and others on Academia.edu. I also took notes on an interesting book about Max Weber's sociology of culture. And, just for the heck of it, here are thoughts on an old book about traditional Chinese culture.
Actually, since this blog entry is already totally random, I might as well also provide a link to brief summaries I wrote years ago of some famous economists.