Plato, Laws 789d

ὅτι τὰ σώματα πάντα ὑπὸ τῶν σεισμῶν τε καὶ κινήσεων κινούμενα ἄκοπα ὀνίναται πάντων, ὅσα τε ὑπὸ ἑαυτῶν, ἢ καὶ ἐν αἰώραις ἢ καὶ κατὰ θάλατταν, ἢ καὶ ἐφʼ ἵππων ὀχουμένων καὶ ὑπʼ ἄλλων ὁπωσοῦν δὴ φερομένων τῶν σωμάτων, κινεῖται, καὶ διὰ ταῦτα τὰς τῶν σίτων τροφὰς καὶ ποτῶν κατακρατοῦντα, ὑγίειαν καὶ κάλλος καὶ τὴν ἄλλην ῥώμην ἡμῖν δυνατά ἐστι παραδιδόναι. τί οὖν ἂν φαῖμεν ἐχόντων οὕτω τούτων τὸ μετὰ τοῦτο ἡμᾶς δεῖν ποιεῖν; βούλεσθε

whether they are moved by their own action—as in a swing or in a rowing-boat—or are carried along on horseback or by any other rapidly moving bodies; and that this is the reason why bodies can deal successfully with their supplies of meat and drink and provide us with health and beauty, and strength as well. This being the state of the case, what does it behove us to do in the future? Shall we risk ridicule,