Three locations of the good. A triptych-passage: where each supposes (ὑπολαμβάνει — an act of TERMjudgment) his own TERMgood to lie. The fame-lover (φιλόδοξος) — in another's activity (ἀλλοτρία ἐνέργεια): his good is in the hands of others who appraise him. The pleasure-lover (φιλήδονος) — in his own sensation (πεῖσις), a passive state of the body. The TERMman of understanding (ὁ νοῦν ἔχων) — in his own action (ἰδία πρᾶξις). The governing discipline is assent (where you place value); the sustaining one is action.
Only one's own action is in one's power. The key is the contrast "another's / one's own sensation / one's own action." The first two goods are not DOGMAup to us: another's activity is outside me, and sensation is passive (it happens to me). Only πρᾶξις — an active deed born of assent and impulse — is truly mine. Hence the good of the rational being is self-sufficient: it lies where nothing external can take it away.
Parallels. The DOGMAdichotomy of control; TERMjudgment as the locus of value — 06-52; cf. 06-16 (value lies in the internal); Med. 9.16 (the good and evil of the rational being lie in activity, not in passivity, ἐν ἐνεργείᾳ, οὐκ ἐν πείσει).