Plutarch’s De Genio Socratis (“On the Sign of Socrates”) differs from much of the work lumped together in his Moralia in that (1) it is a dialogue not a treatise and (2) it is historical, set around 379 BCE. In it, a group debates events around the rise of Theban hegemony; but they also argue about whether or not Socrates had special communiques from the gods.
“My father interrupted and said ‘Galaxidoros, I myself have heard instead from a certain Megarian, who heard it from Terpsion, that Socrates’ divine sign was a sneeze, either his own or one from others. So, when someone sneezed on his right side, whether in front of him or behind him, he went to action there; if on the left, he turned away. One of his own sneezes was a confirmation either to continue what he was about to do or to stop if it happened after he had begun.
But it seems surprising that Socrates would use a sneeze as such a sign and yet he used to tell his friends that it was a divine signal that hindered or encouraged him, and not that. This, my friend, is some kind of empty and meaningless claim, not one of truth and simplicity which we might credit as true in a great man who differed from so many, that he might be so dumfounded by a voice from without or some sneeze that he would refrain from action and give up something he had planned.’ ”
ὑπολαβὼν δ’ ὁ πατήρ ‘ἀλλὰ μήν’ ἔφη ‘καὶ αὐτός, ὦ Γαλαξίδωρε, Μεγαρικοῦ τινος ἤκουσα, Τερψίωνος δὲ ἐκεῖνος, ὅτι τὸ Σωκράτους δαιμόνιον πταρμὸς ἦν, ὅ τε παρ’ αὐτοῦ καὶ ὁ παρ’ ἄλλων. ἑτέρου μὲν γὰρ πταρόντος ἐκ δεξιᾶς εἴτ’ ὄπισθεν εἴτ’ ἔμπροσθεν ὁρμᾶν αὐτὸν ἐπὶ τὴν πρᾶξιν, εἰ δ’ ἐξ ἀριστερᾶς, ἀποτρέπεσθαι· τῶν δ’ αὐτοῦ πταρμῶν τὸν μὲν ἔτι μέλλοντος βεβαιοῦν τὸν δ’ ἤδη πράσσοντος ἐπέχειν καὶ κωλύειν τὴν ὁρμήν. ἀλλ’ ἐκεῖνό μοι δοκεῖ θαυμαστόν, εἰ πταρμῷ χρώμενος οὐ τοῦτο τοῖς ἑταίροις ἀλλὰ δαιμόνιον εἶναι τὸ κωλῦον ἢ κελεῦον ἔλεγε· τύφου γὰρ ἂν ἦν τινος, ὦ φίλε, κενοῦ καὶ κόμπου τὸ τοιοῦτον, οὐκ ἀληθείας καὶ ἁπλότητος οἷς τὸν ἄνδρα μέγαν ὡς ἀληθῶς καὶ διαφέροντα τῶν πολλῶν γεγονέναι δοκοῦμεν, ὑπὸ φωνῆς ἔξωθεν ἢ πταρμοῦ τινος ὁπηνίκα τύχοι θορυβούμενον ἐκ τῶν πράξεων ἀνατρέπεσθαι καὶ προΐεσθαι τὸ δεδογμένον.