Socrates

A stonemason's son who wrote nothing and cross-examined everyone, on the grounds that an unexamined life was not worth living. Athens tried him for impiety and corrupting the young, and he was convicted by a jury of several hundred citizens and executed by hemlock.

He is why 517a says what it says. The man telling the story of a freed prisoner murdered on his return is describing, in an allegory, something that had already happened to his teacher — and that is the fact this app had to make a decision about.