There are many avenues of testimony that are close in date to Socrates’ lifetime.
- Four comic plays ranging from the 420s to the 400s BCE: a character satirically representing him appeared in Aristophanes’ Clouds (423-419 BCE) and Ameipsias’ Konnos (fragmentary, 423 BCE); one of his circle, Chaerephon, is a character in Aristophanes’ Birds (414 BCE); Socrates gets mentioned as a well-known public figure in that play and also in Aristophanes’ Frogs (405 BCE).
- Plato’s Socratic dialogues.
- Xenophon’s Socratic dialogues, and the Hellenica (ca. 380s to 360s).
- Evidence that at least six other members of Socrates’ circle wrote about him, though the works themselves are lost: Lysias’ Apology (almost certainly earlier than Plato’s and Xenophon’s Apologies, which appear to be replies to Lysias in some ways); numerous works by Antisthenes; seven dialogues by Aeschines; six by Euclides; two by Phaedo; and vague reports of writings by Aristippus. Of these, Lysias is better known as a legal speechwriter (several dozen of his speeches survive); Antisthenes was regarded as the most important of Socrates’ pupils for the first few years after Socrates’ death, and was firmly opposed to Plato’s philosophy in some important respects; Euclides’ philosophy was, according to the report we have, closely similar to Socrates’ own; Aristippus went professional and took payment for his teachings, and taught (as Epicurus also did, later on) that pleasure was the highest goal in life.
- Copious evidence of other members of Socrates’ circle who had political and other historical significance during Socrates’ lifetime. Alcibiades was one of the most significant generals in the Peloponnesian War; Critias was an ally of Alcibiades, and went on to become one of the Thirty Tyrants whose short-lived regime brutalised and terrorised the people of Athens in 404 BCE; Charmides was involved in a high-profile court case near the end of the Peloponnesian War, and a minister for the Thirty Tyrants, and he and Critias were involved in an attempted coup d’état in 411 BCE. Critias is also the author of a play, Sisyphus, of which a substantial fragment survives that is radically atheist in tone.
And from about 350 BCE onwards:
- Aeschines Against Timarchus 173 (shortly after 346 BCE; not the same Aeschines as above)
- A letter from Speusippus (Plato’s successor as head of the Academy) to Philip of Macedonia
- A statue by the fourth century sculptor Lysippus, which survives in Roman copies
- References in the writings of Aristotle, Arcesilaus, and several Stoics
- A strong biographical tradition attested in later sources (like Cicero, Diogenes Laertius, and others) which is definitely not derived from Plato.
Aeschines’ testimony, in particular, is useful for interpreting the events surrounding Socrates’ death, which are otherwise reported only by allies of Socrates. Aeschines confirms that Socrates’ execution was closely linked to his association with Critias and Critias’ crimes. This is obviously a very different picture from that painted by Plato’s Apology: Plato’s version of Socrates attempts to derail the prosecution by trying to imply that the real target of the charges is an illusory figure, like the caricature by Aristophanes.
The problems with Socrates’ biography are similar to those surrounding Jesus to the extent that his followers mythologized him a great deal. This can be seen particularly in their extreme defensiveness with respect to his trial, and their insistence that he stood up to the Thirty Tyrants when they instructed him to arrest and execute one of their political opponents. Whether that story is true or not, it’s obviously not the whole story: the fact remains that Alcibiades, Critias, and Charmides were all closely linked to Socrates, they all tried to subvert the state in some important ways, and his own hands simply cannot have been totally clean.
His situation is very different from that surrounding Jesus in the sense that Socrates was linked to numerous figures who loom large in historical accounts of the period, and indeed served as a hoplite in two well-attested battles of the Peloponnesian War. But mythologization by followers, and ties (or lack of ties) to political figures, have never been good reasons to dismiss available evidence as though it were wholly made-up.