I haven’t done one of these in a while, but I couldn’t let what I found around the close of book five slide. Near the end of that book, Athens makes an expedition against the small island of Melos. But before they invade, they send a few representatives to the islands to negotiate with the Melians. Here’s how, near the beginning of the ensuing dialogue, the Athenians justify the pending invasion:
For ourselves, we shall not trouble you with specious pretenses — either of how we have a right to our empire because we overthrew the Mede, or are now attacking you because of a wrong that you have done us — and make a long speech which would not be believed; and in return we hope that you, instead of thinking to influence us by saying that you did not join the Spartans, although their colonists, or that you have done us no wrong, will aim at what is feasible, holding in view the real sentiments of us both; since you know as well as we do that right, as the world goes, is only in question between equals in power, while the strong do what they can and the weak suffer what they must.
That sounds an awful lot like what Thrasymachus tells Socrates in Plato’s Republic: that justice “is nothing but the advantage of the stronger.”
The Athenians attacked Melos in 416 BCE, Socrates drank the hemlock in 399, and Plato wrote the Republic somewhere around 380. I don’t know if Thrasymachus’ argument was supposed to be representative of popular Athenian opinion; nor do I know how much of Socrates’ positive moral realist argument in the Republic actually came from Socrates, and wasn’t just Plato putting words in the mouth of his mentor and surrogate. But if we take Thucydides’ transcription of events as evidence that Athenians were largely Thrasymachans, and if we take Plato at his word regarding Socrates’ metaethical beliefs, then all of this adds a new shade to popular understandings of the trial of Socrates.
The beliefs that got Socrates killed are generally understood to be negative beliefs. He is said to have questioned the gods, or challenged democratic rule. But maybe his moral realist critique also got him in some trouble. Applying Socratic standards, Athenian behavior during the Peloponnesian War certainly doesn’t look all that stellar. Maybe the shame of the Athenians helped doom Socrates.
But hey, what do I know? I’m no classicist, and this is just uninformed speculation. I’d like to hear from some people who know more about this.