Plato, Epinomis 992a

γὰρ πεφυκὼς πάντων τούτων εἷς ἀναφανήσεται διανοουμένοις —εἰ δʼ ἄλλως πως ταῦτα μεταχειριεῖταί τις, τύχην δεῖ καλεῖν, ὥσπερ καὶ λέγομεν. οὐ γὰρ ἄνευ γε τούτων μήποτέ τις ἐν πόλεσιν εὐδαίμων γένηται φύσις, ἀλλʼ οὗτος ὁ τρόπος, αὕτη ἡ τροφή, ταῦτα τὰ μαθήματα· εἴτε χαλεπὰ εἴτε ῥᾴδια, ταύτῃ πορευτέον. ἀμελῆσαι δὲ οὐ θεμιτόν ἐστιν θεῶν, καταφανοῦς γενομένης τῆς πάντων αὐτῶν κατὰ τρόπον λεγομένης φήμης

for it will be manifest to us, as we reflect, that there is one bond naturally uniting all these things: but if one goes about it in some other way, one must call it Fortune, as we also put it. For never, without these lessons, will any nature be happy in our cities: no, this is the way, this the nurture, these the studies, whether difficult or easy, this the path to pursue: to neglect the gods is not permissible, when it has been made manifest that the fame of them, stated in proper terms, hits the mark.