Things going for it:
1. Gets it right.
2. Reclaims Aristotle's reputation from the damage done by that ho Mary Renault. ^_^
3. Believable vocabulary. Yes, stick to standard English for your historical fic; it works.
4. Believable attitudes. The sympathetic hero regrets not having a slave put to judicial torture when he had the chance in order to get the man's testimony. The hero is a very nice man but slaves under examination in Athens were always tortured. That was how it was done. And you can see from what he says that the very nice hero doesn't think of slaves or foreigners as human like himself. He's an Athenian. They're... slaves and foreigners. Different. His attitudes are appalling by our standards and he's still the sympathetic hero. Renault included a footnote about this but Doody shows it up close, is why Doody's Athens strikes me as more accurate than Renault's romanticized one in The Last of the Wine. (Qui est joli quand même, il faut dire.)