Diodorus Siculus, History 32.12
“Similarly in Naples and many other places there are accounts that sudden changes like this happened—not that male and female were naturally built into a two-bodied type (for that is impossible) but that much to the surprise and mystification of human beings, nature forms some parts of the body deceptively.
This is why we think it is right to describe these kinds of sex changes: not to entertain but so we can help those who are reading this. For there are many people who believe that these kinds of things are signs for the gods and not isolated individuals but even entire communities and cities. For example, at the beginning of the Marsian war, they say that there was an Italian living near Rome who had married, a hermaphrodite like the one we mentioned earlier and revealed this to his senate. The senate, overwhelmed by superstition and persuaded by the Etruscan interpreters, decided that they should be burned alive. In this case, a person who was like us in nature and was not in truth any monster died unfairly because of the ignorance about their affliction. When there was a similar case near Athens a little while later, they again burned a person alive through ignorance.
People also make up stories about hyenas, that they are female and male at the same time and that they take turns mounting each other annually when this is completely untrue. Each sex has its own kind of nature and they are not mixed up. But there is a time when something deceives when it is presented to someone who is merely glancing. The female has an appendage that looks something like a male feature; and the male has one which corresponds to the female’s.
This is generally the case for all living creatures. Although many monsters of all kinds are born, in truth, they cannot be nourished and are not capable of growing to maturity. Let this be enough said as a redress against superstitious beliefs.”
῾Ομοίως δ’ ἐν τῇ Νεαπόλει καὶ κατ’ ἄλλους τόπους πλείονας ἱστοροῦνται γεγονέναι τοιαῦται περιπέτειαι, οὐκ ἄρρενος καὶ θηλείας φύσεως εἰς δίμορφον τύπον δημιουργηθείσης, ἀδύνατον γὰρ τοῦτο, ἀλλὰ τῆς φύσεως διὰ τῶν τοῦ σώματος μερῶν ψευδογραφούσης εἰς ἔκπληξιν καὶ ἀπάτην τῶν ἀνθρώπων.
διόπερ καὶ ἡμεῖς τὰς περιπετείας ταύτας ἀναγραφῆς ἠξιώσαμεν, οὐ ψυχαγωγίας ἀλλ’ ὠφελείας ἕνεκα τῶν ἀναγινωσκόντων. πολλοὶ γὰρ τέρατα τὰ τοιαῦτα νομίζοντες εἶναι δεισιδαιμονοῦσιν, οὐκ ἰδιῶται μόνον ἀλλὰ καὶ ἔθνη καὶ πόλεις. κατ’ ἀρχὰς γοῦν τοῦ Μαρσικοῦ πολέμου πλησίον τῆς ῾Ρώμης οἰκοῦντά φασιν ᾿Ιταλικόν, γεγαμηκότα παραπλήσιον τοῖς εἰρημένοις ἀνδρόγυνον, προσαγγεῖλαι τῇ συγκλήτῳ, τὴν δὲ δεισιδαιμονήσασαν καὶ τοῖς ἀπὸ Τυρρηνίας ἱεροσκόποις πεισθεῖσαν ζῶντα προστάξαι καῦσαι. τοῦτον μὲν οὖν ὁμοίας κεκοινωνηκότα φύσεως, ἀλλ’ οὐ πρὸς ἀλήθειαν τέρας γεγενημένον, φασὶν ἀγνοίᾳ τῆς νόσου παρὰ τὸ προσῆκον ἀπολωλέναι. μετ’ ὀλίγον δὲ καὶ παρ’ ᾿Αθηναίοις τοῦ τοιούτου γενομένου διὰ τὴν ἄγνοιαν τοῦ πάθους ζῶντά φασι κατακαῆναι. καὶ γὰρ τὰς λεγομένας ὑαίνας τινὲς μυθολογοῦσιν ἄρρενας ἅμα καὶ θηλείας ὑπάρχειν, καὶ παρ’ ἐνιαυτὸν ἀλλήλας ὀχεύειν, τῆς ἀληθείας οὐχ οὕτως ἐχούσης. ἑκατέρου γὰρ τοῦ γένους ἁπλῆν ἔχοντος καὶ ἀνεπίμικτον τὴν φύσιν, προσώρισται τὸ ψευδογραφοῦν καὶ παρακρουόμενον τοὺς εἰκῇ θεωροῦντας· τῇ μὲν γὰρ θηλείᾳ πρόσκειταί τι κατὰ τὴν φύσιν παρεμφερὲς ἄρρενι μορίῳ, τῷ δὲ ἄρρενι κατὰ τὸ ἐναντίον ἔμφασις θηλείας φύσεως. ὁ δ’ αὐτὸς λόγος καὶ ἐπὶ πάντων τῶν ζῴων, γινομένων μὲν πρὸς ἀλήθειαν πολλῶν καὶ παντοδαπῶν τεράτων, μὴ τρεφομένων δὲ καὶ εἰς τελείαν αὔξησιν ἐλθεῖν οὐ δυναμένων. ταῦτα μὲν εἰρήσθω πρὸς διόρθωσιν δεισιδαιμονίας.
Some other related resources:
Hilary Ilkay’s essay on “Ovid’s Mythological Hermaphrodite”
Cassie Garrison’s Essay on “Gender and Sexuality in Antiquity: The Trial and Consciousness of Callon”