Two triumvirates. Marcus sets two threes against each other: the conquerors — PERSONAlexander, Gaius, Pompey — and the philosophers — PERSONDiogenes, PERSONHeraclitus, PERSONSocrates. The question "τί πρός;" ("what are they beside?") is rhetorical: the fame of rulers pales next to those who mastered not lands but themselves. Cf. 6.24, where death has already leveled Alexander with his muleteer.
Why the philosophers rank higher. Not by virtue in general, but by a specific work of mind: they "saw the things, the causes, and the matter" (τὰ πράγματα, τὰς αἰτίας, τὰς ὕλας) — the threefold dissection of any object, the EXERCISEanalytic definition (cf. the canonical 8.11: "what is this in itself, in its structure, in its matter"; 12.10, 12.18). One who sees a thing through — down to cause and stuff — is not enslaved by it. Hence their "ruling faculties were the same" (τὰ TERMἡγεμονικὰ ἦν αὐτῶν ταὐτά): their DOGMAgoverning faculty is identical with itself, unsplit by passion and independent of externals.
Care and slavery. The reverse side belongs to the conquerors: "for how many things had they care (πρόνοια), and of how many were they slaves (δουλεία)." There is a fine irony in πρόνοια: what in the cosmos is providence becomes, in the ruler, an exhausting oversight of countless things — and the conqueror's "freedom" is slavery. The strict term by the word is ἡγεμονικόν; αἰτία and ὕλη are left without term-cards (not established in the corpus). The governing discipline is assent (the right seeing of essence), the sustaining one desire (not to prize outward power).