Fair for Its Day: He wouldn't exactly sign on to the Geneva Conventions, but he was a believer in liberty (for those who deserved it).
Values Dissonance: He had values dissonance at the time for recommending classical pagan values over many of the Christian ones, as well as for advocating quite a bit of liberty. Oddly, the values dissonance seems to have shrunk over time in some ways (though slaughtering the male residents of a city tends to be frowned upon these days).
Vindicated by History: Even if his name is vilified these days, the US constitution is based in many places on his ideas, especially the idea of mixed government (separation of powers). His recommendation to mix Monarchy (the Presidency), Aristocracy (originally the Senate, but now more the Supreme Court), and Democracy (Congress and the right to protest) have worked fairly well.
Even more obvious with the UK, where the power is (at least nominally) split between the Queen (officially a Monarch), the House of Lords (officially Aristocrats) and the House of Commons (elected).