Πρὸς γὰρ ὑγιείας καὶ νόσους ἀρετάς τε καὶ κακίας οὐδεμία συμμετρία καὶ ἀμετρία μείζων ἢ ψυχῆς αὐτῆς πρὸς σῶμα αὐτό· ὧν οὐδὲν σκοποῦμεν οὐδ’ ἐννοοῦμεν, ὅτι ψυχὴν ἰσχυρὰν καὶ πάντῃ μεγάλην ἀσθενέστερον καὶ ἔλαττον εἶδος ὅταν ὀχῇ, καὶ ὅταν αὖ τοὐναντίον συμπαγῆτον τούτω, οὐ καλὸν ὅλον τὸ ζῷον—ἀσύμμετρον γὰρ ταῖς μεγίσταις συμμετρίαις—τὸ δὲ ἐναντίως ἔχον πάντων θεαμάτων τῷ δυναμένῳ καθορᾶν κάλλιστον καὶ ἐρασμιώτατον. οἷον οὖν ὑπερσκελὲς ἢ καί τινα ἑτέραν ὑπέρεξιν ἄμετρον ἑαυτῷ τι σῶμα ὂν ἅμα μὲν αἰσχρόν, ἅμα δ᾽ ἐν τῇ κοινωνίᾳ τῶν πόνων πολλοὺς μὲν κόπους, πολλὰ δὲ σπάσματα καὶ διὰ τὴν παραφορότητα πτώματα παρέχον μυρίων κακῶν αἴτιον ἑαυτῷ, ταὐτὸν δὴ διανοητέον καὶ περὶ τοῦ συναμφοτέρου, ζῷον ὃ καλοῦμεν, ὡς ὅταν τε ἐν αὐτῷ ψυχὴ κρείττων οὖσα σώματος περιθύμως ἴσχῃ, διασείουσα πᾶν αὐτὸ ἔνδοθεν νόσων ἐμπίμπλησι, καὶ ὅταν εἴς τινας μαθήσεις καὶ ζητήσεις συντόνως ἴῃ, κατατήκει, διδαχάς τ’ αὖ καὶ μάχας ἐν λόγοις ποιουμένη δημοσίᾳ καὶ ἰδίᾳ δι’ ἐρίδων καὶ φιλονικίας γιγνομένων διάπυρον αὐτὸ ποιοῦσα σαλεύει, καὶ ῥεύματα ἐπάγουσα, τῶν λεγομένων ἰατρῶν ἀπατῶσα τοὺς πλείστους, τἀναίται αἰτιᾶσθαι ποιεῖ· σῶμά τε ὅταν αὖ μέγα καὶ ὑπέρψυχον σμικρᾷ συμφυὲς ἀσθενεῖ τε διανοίᾳ γένηται, διττῶν ἐπιθυμιῶν οὐσῶν φύσει κατ᾽ ἀνθρώπους, διὰ σῶμα μὲν τροφῆς, διὰ δὲ τὸ θειότατον τῶν ἐν ἡμῖν φρονήσεως, αἱ τοῦ κρείττονος κινήσεις κρατοῦσαι καὶ τὸ μὲν σφέτερον αὔξουσαι, τὸ δὲ τῆς ψυχῆς κωφὸν καὶ δυσμαθὲς ἀμνῆμόν τε ποιοῦσαι, τὴν μεγίστην νόσον ἀμαθίαν ἐναπεργάζονται.
(Plato, Timaeus 87d-88b)
For instance, the factor that has the most bearing on health and sickness, and on moral goodness and badness, is whether or not there’s proportion between soul and body, but we don’t consider these things at all. We fail to see that when a relatively weak and frail body is the vehicle for a soul that has no weakness or pettiness in it, or when the combination of the two of them is imbalanced in the opposite way, the creature as a whole lacks proportion in the most important respects, and therefore lacks beauty. However, for those capable of seeing it, a creature whose soul and body are in balance is a vision of the utmost beauty and attractiveness. Think, for example, of a body which is out of proportion with itself, in the sense that it has one leg longer than the other or some other abnormality: it’s not just that it’s ugly, but also that it makes a lot of trouble for itself in a work context, as its lurching gait exhausts it and makes it liable to all sorts of injuries and accidents. The same goes, we’re bound to think, for the complex of soul and body that we call a living creature. Suppose its soul is stronger than its body. When the soul gets abnormally passionate, it makes the whole body quiver from within and fills it with illnesses; and when it’s intent upon study and research, it causes the body to waste away. Or again, when it’s involved in teaching or disputation, in public or in a private house, surrounded by arguments and competitiveness, it heats the body and churns it up, and induces fluxes, which fool most so-called healers into blaming the innocent party. On the other hand, the balance of power might lie with the body rather than the soul, so that a strong body has a petty, weak mind attached to it. If so, of the two fundamental desires that human beings possess—the bodily desire for food and the desire of the most divine part of us for knowledge… well, when the impulses of the stronger part win and reinforce their favourite, they turn the soul into something obtuse, dull, and forgetful, and give it the worst of all diseases, ignorance. (tr. Robin Waterfield)