The same rite can have different meanings
The reason for the circumcision of the Jews is not the same as the reason for the circumcision of the Egyptians or of the Colchians, and so it could not be thought the same circumcision. Just as one who sacrifices does not sacrifice to the same being, even if he seems to sacrifice in the same way, and one who prays does not pray to the same being, even if he asks for the same things in his prayers, so too, when someone is circumcised, it is not in every case the same as circumcision directed to another. For the purpose, the law and the intention of the one who circumcises make the act different.
To make the point of this subject still clearer, it must be said that the name of justice is the same among all the Greeks; yet it is shown that justice according to Epicurus is one thing; justice according to the Stoics, who deny that the soul has three parts, is another; and justice according to the Platonists, who say that justice is each part of the soul doing its own work, is another again. So too the courage of Epicurus, who endures pains to escape greater pains, is one thing; the courage of the Stoic, who chooses every virtue for its own sake, is another; and courage according to Plato, who says that it is the virtue of the spirited part of the soul and assigns to it a place about the chest, is another again.
In the same way circumcision would differ according to the different doctrines of those who are circumcised. About this it is not necessary to speak now in a work of this kind; whoever wishes to see what moved us on this subject may read what we have written about it in our treatment of Paul's Epistle to the Romans.
Greek
Τὸ δ᾿ αἴτιον τῆς Ἰουδαίων περιτομῆς οὐ ταὐτὸν ἐστι τῷ αἰτίῳ τῆς Αἰγυπτίων περιτομῆς ἢ Κόλχων· διὸ οὐχ ἡ αὐτὴ νομισθείη ἂν περιτομή. καὶ ὥσπερ ὁ θύων οὐ τῷ αὐτῷ θύει, εἰ καὶ ὁμοίως θύειν δοκεῖ. καὶ ὁ εὐχόμενος οὐ τῷ αὐτῷ εὔχεται, εἰ καὶ τὰ αὐτὰ ἐν ταῖς εὐχαῖς ἀξιοῖ· οὕτως οὐδ᾿ εἴ τις περιτέμνεται, ἀδιαφορεῖ πάντως τῆς πρὸς ἕτερον περιτομῆς. ἡ γὰρ πρόθεσις καὶ ὁ νόμος καὶ τὸ βούλημα τοῦ περιτέμνοντος ἀλλοῖον ποιεῖ τὸ πρᾶγμα. ἵνα δ᾿ ἔτι μᾶλλον νοηθῇ τὸ κατὰ τὸν τόπον, λεκτέον ὅτι τὸ τῆς δικαιοσύνης ὄνομα ταὐτὸν μέν ἐστι παρὰ πᾶσιν Ἕλλησιν· ἤδη δὲ ἀποδείκνυται ἄλλη μὲν ἡ κατ᾿ Ἐπίκουρον δικαιοσύνη, ἄλλη δὲ ἡ κατὰ τοὺς ἀπὸ τῆς Στοᾶς, ἀρνουμένους τὸ τριμερὲς τῆς ψυχῆς, ἄλλη δὲ κατὰ τοὺς ἀπὸ Πλάτωνος, ἰδιοπραγίαν τῶν μερῶν τῆς ψυχῆς φάσκοντας εἶναι τὴν δικαιοσύνην. οὕτω δὲ καὶ ἄλλη μὲν ἡ Ἐπικούρου ἀνδρεία, ὑπομένοντος πόνους διὰ φυγὴν πόνων πλειόνων, ἄλλη δ᾿ ἡ τοῦ ἀπὸ τῆς Στοᾶς, δι᾿ αὐτὴν αἱρουμένου πᾶσαν ἀρετὴν. ἄλλη δ᾿ ἡ ἀπὸ Πλάτωνος, τοῦ θυμικοῦ μέρους τῆς ψυχῆς φάσκοντος αὐτὴν εἶναι ἀρετὴν καὶ ἀποτάσσοντος αὐτῇ τόπον τὸν περὶ τὸν θώρακα. οὕτως δ᾿ εἴη ἂν κατὰ τὰ διάφορα τῶν περιτεμνομένων δόγματα διάφορος ἡ περιτομὴ, περὶ ἧς ἐν τοιούτῳ συγγράμματι οὐκ ἀναγκαῖον νῦν λέγειν· ὅτῳ γὰρ φίλον ἰδεῖν τὰ κινήσαντα ἡμᾶς εἰς τὸν τόπον, ἀναγνώτω περὶ αὐτοῦ ἐν τοῖς εἰς τὴν πρὸς Ῥωμαίους ἐπιστολὴν Παύλου πραγματευθεῖσιν ἡμῖν.