In Antiquities, one of my monthly reads, Norman F. Cantor disassembles philosophers via a short and brutal sociological analysis of Plato, Socrates and Aristotle. It's done with such surgical precision that it will leave you breathless (and suddenly understanding certain wailing liberals a lot better.) Cantor is not a lit-snob, though; he does the same thing to religion and other foundations of civilization. No malice involved, no emotional garbage through which you must wade; clean and dry and laser-precise.
Highly recommend this one, but only if you're prepared to have most of what you believe in presented to you in a very different light.