§51.1Fr. 51
Καλῶς ὁ Πλάτων τὴν φυσιολογίαν εἰκοτολογίαν ἔλεγεν εἶναι, ᾧ καὶ Ἀριστοτέλης συμμαρτυρεῖ, τὴν κυρίως ἀπόδειξιν ἐξ ἀμέσων καὶ ἀξιοπίστων ἀρχῶν καὶ ἐκ τῶν κυρίως αἰτίων καὶ τῇ φύσει προτέρων εἶναι βουλόμενος.
Plato rightly said that the study of nature is a plausible account, to which Aristotle also bears witness, wishing that proper demonstration should derive from immediate and credible principles, and from causes that are proper and prior by nature.
Ἀλλʼ οὐκ ἀτιμαστέον διὰ τοῦτο φυσιολογίαν, ἀλλʼ ἀρκεῖσθαι χρὴ τῷ κατὰ τὴν ἡμετέραν χρῆσιν καὶ δύναμιν ὡς καὶ Θεοφράστῳ δοκεῖ.
But one must not on this account disparage the study of nature, but must be content with what is according to our use and capacity, as it also seems to Theophrastus.