The three terms ‘logic,’ ‘physics,’ and ‘ethics’ name three manners and directions of understanding beings as a whole. Did these three directions of universal knowledge come together by happenstance, or do they originate in a concealed togetherness that entrusts them to one another? We intuit something of this togetherness, even if we do not yet see clearly where it originates or on what it is grounded (i.e., where the unity of these three directions of knowledge has its starting point, its ‘principle’). If these three terms—and most importantly, what they name—belong together in a unity, then this unity contains a structure and an arrangement. Only with this structure and arrangement in mind can the tripartite division be executed.
Regarding the provenance of this tripartite division, we have the report of Sextus Empiricus, a philosophical writer who lived around 200 ad . In his work, Adversus Mathematicos, Book 7, § 16, he states the following:
ἐντελέστερον δὲ [λέγουσιν τὰ μέρη τῆς φιλοσοφίας] . . . οἱ εἰπόντες τῆς φιλοσοφίας τὸ μέν τι εἶναι φυσικὸν τὸ δὲ ἠθικὸν τὸ δὲ λογικόν· ὧν δυνάμει μὲν Πλάτων ἐστὶν ἀρχηγός, περὶ πολλῶν μὲν [226] φυσικῶν [περὶ] πολλῶν δὲ ἠθικῶν οὐκ ὀλίγων δὲ λογικῶν διαλεχθείς· ῥητότατα δὲ οἱ περὶ τὸν Ξενοκράτην καὶ οἱ ἀπὸ τοῦ περιπάτου ἔτι δὲ οἱ ἀπὸ τῆς στοᾶς ἔχονται τῆσδε τῆς διαιρέσεως .