Julian, To the Cynic Heracleios, Oration 7 (215d-216b)
“I should now say a little bit about the divisions or tools of philosophy. For it is no big deal whether someone applies logic with practical or natural philosophy, for it is similarly necessary in both cases. But these three divisions can each be split into three others. Natural philosophy has theology, mathematics and as a third the examination of things that develop and perish and those that are unseen and which concerns what their essence is and existence entails for each one.
Practical philosophy, because it concerns a single man, has ethics, economics—when it pertains to a household—and politics—when it concerns the state. Logic in turn is demonstrative through truths, but rather violent when dealing with opinions or polemical when concerned with beliefs that merely appear to be true.
These are the subdisciplines of philosophy unless something has escaped me. Indeed, it would not be shocking were some mere soldier incapable of precisely describing or managing these kinds of definitions, since they come not from book learning but from observation and some experience. You can be my witnesses for this to, if you consider how many days there were because the lecture we recently heard and today and in addition the number of matters which have taken my attention. But, the thing I was saying, if I missed anything, and I really don’t think I did, if someone else can finish it, he won’t be my enemy but my friend.”
Μικρὰ οὖν ὑπὲρ τῶν τῆς φιλοσοφίας εἴτε μορίων εἴτε ὀργάνων προρρητέον. ἔστι γὰρ οὐ μέγα τὸ διαφέρον ὁποτέρως ἄν τις τῷ πρακτικῷ καὶ τῷ φυσικῷ τὸ λογικὸν προσαριθμῇ· ἀναγκαῖον γὰρ ὁμοίως φαίνεται κατ᾿ ἀμφότερα. τριῶν δὴ τούτων αὖθις ἕκαστον εἰς τρία τέμνεται, τὸ μὲν φυσικὸν εἰς τὸ θεολογικὸν καὶ τὸ περὶ τὰ μαθήματα καὶ τρίτον τὸ περὶ τὴν τῶν γινομένων καὶ ἀπολλυμένων καὶ τῶν ἀιδίων μέν, σωμάτων δὲ ὅμως θεωρίαν, τί τὸ εἶναι αὐτοῖς καὶ τίς ἡ οὐσία ἑκάστου· τοῦ πρακτικοῦ δὲ τὸ μὲν πρὸς ἕνα ἄνδρα, ἠθικόν, οἰκονομικὸν δὲ τὸ περὶ μίαν οἰκίαν, πολιτικὸν δὲ τὸ περὶ πόλιν· ἔτι μέντοι τοῦ λογικοῦ τὸ μὲν ἀποδεικτικὸν διὰ τῶν ἀληθῶν, τὸ δὲ διὰ τῶν ἐνδόξων βιαστικόν, τὸ δὲ διὰ τῶν φαινομένων ἐνδόξων παραλογιστικόν. ὄντων δὴ τοσούτων τῶν τῆς φιλοσοφίας μερῶν, εἰ μή τί με λέληθε· καὶ οὐδὲν θαυμαστὸν ἄνδρα στρατιώτην μὴ λίαν ἐξακριβοῦν μηδ᾿ ἐξονυχίζειν τὰ τοιαῦτα, ἅτε οὐκ ἐκ βιβλίων ἀσκήσεως, ἀπὸ δὲ τῆς προστυχούσης αὐτὰ ἕξεως ἀποφθεγγόμενον· ἔσεσθε γοῦν μοι καὶ ὑμεῖς μάρτυρες, εἰ τὰς ἡμέρας λογίσαισθε, πόσαι τινές εἰσιν αἱ μεταξὺ ταύτης τε καὶ τῆς ἔναγχος ἡμῖν γενομένης ἀκροάσεως ὅσων τε ἡμῖν ἀσχολιῶν πλήρεις· ἀλλ᾿, ὅπερ ἔφην, εἰ καί τι παραλέλειπται παρ᾿ ἐμοῦ· καίτοι νομίζω γε μηδὲν ἐνδεῖν· πλὴν ὁ προστιθεὶς οὐκ ἐχθρός, ἀλλὰ φίλος ἔσται.