Aristotle, Parts of Animals IV 689a
“The male organ has differences akin to those throughout the whole body. For some animals are completely sinewy, others are not. And this is the only one of the appendages which experiences increase and decrease in size without any disease. The first of these qualities is useful for copulation; the second is good for the use of the rest of the body. For it would impede the rest of the body if it were always distended.
By nature, then, it is made up of those kinds of materials which are able to do both of these things. For it has both sinew and cartilage and for this reason it can contract and expand and can admit air into itself.”
ἔχει δὲ διαφορὰς τὸ τῶν ἀρρένων ὄργανον κατὰ τὰς τοῦ σώματος διαφοράς. οὐ γὰρ ὁμοίως ἅπαντα νευρώδη τὴν φύσιν ἐστίν. ἔτι δὲ μόνον τοῦτο τῶν μορίων ἄνευ νοσερᾶς μεταβολῆς αὔξησιν ἔχει καὶ ταπείνωσιν· τούτων γὰρ τὸ μὲν χρήσιμον πρὸς τὸν συνδυασμόν, τὸ δὲ πρὸς τὴν τοῦ ἄλλου σώματος χρείαν· ἀεὶ γὰρ ὁμοίως ἔχον τἆλλα ἐνεπόδιζεν ἄν. συνέστηκε δὲ τὴν φύσιν ἐκ τοιούτων τὸ μόριον τοῦτο ὥστε δύνασθαι ταῦτ᾿ ἀμφότερα συμβαίνειν· τὸ μὲν γὰρ ἔχει νευρῶδες τὸ δὲ χονδρῶδες, διόπερ συνιέναι τε δύναται καὶ ἔκτασιν ἔχειν καὶ πνεύματός ἐστι δεκτικόν.
Aristotle, Problems 879a-b
20 “Sexual excitement is also due to an exiting of breath. If its rush finds some exit while arousal is ongoing then it does not make the semen ejaculate. But instead, it cools. Then, it ruins the rigidity of the penis.”
ἔστι δὲ καὶ ὁ ἀφροδισιασμὸς μετὰ πνεύματος ǁ ἐξόδου. εἰ οὖν ὁδοποιεῖται ἡ ὁρμὴ γινομένου αὐτοῦ, οὐ ποιεῖ ὁρμᾶν τὸ σπέρμα, ἀλλὰ καταψύχεται· μαραίνει οὖν τὴν συντονίαν τοῦ αἰδοίου.
4.23 “Why does rigidity and increase happen to the penis? Is it for two reasons? First, is it because that weight develops on the bottom of the testicles, raising it—for the testicles are like a fulcrum? And is it because the veins become full of breath [pneuma]? Or does the mass become bigger because of an increase in moisture or some change in position or from the development of moisture itself? Extremely large things are raised less when the wight of the fulcrum is far away.”
Διὰ τί ἡ σύντασις γίνεται τοῦ αἰδοίου καὶ ἡ αὔξησις; ἢ διὰ δύο, διά τε τὸ βάρος ἐπιγίνεσθαι ἐν τῷ ὄπισθεν τῶν ὄρχεων αἴρεσθαι (ὑπομόχλιον γὰρ οἱ ὄρχεις γίνονται) καὶ διὰ τὸ πνεύματος πληροῦσθαι τοὺς πόρους; ἢ τοῦ ὑγροῦ αὐξανομένου καὶ μεθισταμένου ἢ ἐξ ὑγροῦ γινομένου ὁ ὄγκος | μείζων γίνεται; τὰ λίαν δὲ μεγάλα ἧττον αἴρεται διὰ τὸ πορρωτέρω τὸ βάρος τοῦ ὑπομοχλίου γίνεσθαι.
