Plutarch, De Iside et Osiride 2

διὸ θειότητος ὄρεξίς ἐστιν ἡ τῆς ἀληθείας μάλιστα δὲ τῆς περὶ θεῶν ἔφεσις, ὥσπερ ἀνάληψιν ἱερῶν τὴν μάθησιν ἔχουσα καὶ τὴν ζήτησιν, ἁγνείας τε πάσης καὶ νεωκορίας ἔργον ὁσιώτερον, οὐχ ἥκιστα δὲ τῇ θεῷ ταύτῃ κεχαρισμένον, ἣν σὺ θεραπεύεις ἐξαιρέτως σοφὴν καὶ φιλόσοφον οὖσαν, ὡς τοὔνομά γε φράζειν ἔοικε, παντὸς μᾶλλον αὐτῇ τὸ εἰδέναι καὶ τὴν ἐπιστήμην προσήκουσαν. Ἑλληνικὸν γὰρ ἡ Ἶσίς ἐστι καὶ ὁ Τυφὼν, ὢν πολέμιος τῇ θεῷ καὶ διʼ ἄγνοιαν καὶ ἀπάτην τετυφωμένος καὶ διασπῶν καὶ ἀφανίζων τὸν ἱερὸν λόγον, ὃν ἡ θεὸς συνάγει καὶ συντίθησι καὶ παραδίδωσι τοῖς τελουμένοις θειώσεως, σώφρονι μὲν ἐνδελεχῶς διαίτῃ καὶ βρωμάτων πολλῶν καὶ ἀφροδισίων ἀποχαῖς κολουούσης τὸ ἀκόλαστον καὶ φιλήδονον, ἀθρύπτους δὲ καὶ στερρὰς ἐν ἱεροῖς λατρείας ἐθιζούσης ὑπομένειν, ὧν τέλος ἐστὶν ἡ τοῦ πρώτου καὶ κυρίου καὶ νοητοῦ γνῶσις, ὃν ἡ θεὸς παρακαλεῖ ζητεῖν παρʼ αὐτῇ καὶ μετʼ αὐτῆς ὄντα καὶ συνόντα. τοῦ δʼ ἱεροῦ τοὔνομα καὶ σαφῶς ἐπαγγέλλεται καὶ γνῶσιν καὶ εἴδησιν τοῦ ὄντος. ὀνομάζεται γὰρ Ἰσεῖον ὡς εἰσομένων τὸ ὄν, ἂν μετὰ λόγου καὶ ὁσίως εἰς τὰ ἱερὰ παρέλθωμεν τῆς θεοῦ.

Therefore the effort to arrive at the Truth, and especially the truth about the gods, is a longing for the divine. For the search for truth requires for its study and investigation the consideration of sacred subjects, and it is a work more hallowed than any form of holy living or temple service; and, not least of all, it is well-pleasing to that goddess whom you worship, a goddess exceptionally wise and a lover of wisdom, to whom, as her name at least seems to indicate, knowledge and understanding are in the highest degree appropriate. For Isis is a Greek word, and so also is Typhon, her enemy, who is conceited, as his name implies, because of his ignorance and self-deception. He tears to pieces and scatters to the winds the sacred writings, which the goddess collects and puts together and gives into the keeping of those that are initiated into the holy rites, since this consecration, by a strict regimen and by abstinence from many kinds of food and from the lusts of the flesh, curtails licentiousness and the love of pleasure, and induces a habit of patient submission to the stem and rigorous services in shrines, the end and aim of which is the knowledge of Him who is the First, the Lord of All, the Ideal One. Him does the goddess urge us to seek, since He is near her and with her and in close communion. The name of her shrine also clearly promises knowledge and comprehension of reality; for it is named Iseion, to indicate that we shall comprehend reality if in a reasonable and devout frame of mind we pass within the portals of her shrines.