Ἀρετὴ αὐτάρκης πρὸς εὐδαιμονίαν — "virtue is sufficient for happiness." One of the hardest and most characteristic Stoic theses: for a happy life (understood as TERMεὔρους βίος — the smooth flow of existence) one needs only virtue, and nothing besides. Health, wealth, reputation, children, country — all these are "indifferents" (ἀδιάφορα); their presence or absence does not alter the status of a life as one that has gone well. The thesis provokes the natural objection ("but the person deprived of health suffers!"), and the Stoic answer: suffering is the artefact of false assents (pathos), not an objective deficit. The sage on the rack is eudaimōn to exactly the same degree as the sage in a palace.

SVF I 187 (Zeno); III 49–67 (Chrysippus' extensive argumentation); the classical formulations: DL VII 127; Stob. Ecl. II 71, 99 W; Cic. De fin. III 27; Tusc. V (the whole — "De virtute ad beate vivendum satis," the principal treatise); Sen. Ep. 9 (on the self-sufficiency of the sage); LS 63. In Marcus the thesis is everywhere assumed, but especially explicit at Med. 1.16; 02-05 ("how few things are needed for the smooth-flowing life"); 04-32 (contentment with one's own task, not chasing vanities); 05-12 (the seeming goods of the many vs true virtue); 05-14 (reason is self-sufficient); 05-15 (only the human is a human's; the τέλος is self-sufficient); 05-34; 05-37 (happiness is good acts of the soul, not the lot that fell); 06-02 (cold or heat, blame or praise, even death — indifferent to "doing what is fitting"); 06-16 (value lies only in the internal; else neither freedom, self-sufficiency, nor ἀπάθεια); 06-30 (the one fruit of earthly life is a holy disposition and social acts); 06-34 (scoundrels too revel in pleasures — so pleasure is no good); 07-28 (the ruling part is sufficient to itself in acting justly — and therein is γαλήνη); 07-42 (a verse of Euripides: "the good is with me — and the just"); 07-44 (Plato, Apol. 28b: look only to the justice of the act, not to life or death); 07-45 (Plato, Apol. 28d: reckon nothing ahead of the shameful); 07-66 (Socrates' measure — content with justice and piety, not glory); 07-67 (in the very least lies εὐδαιμόνως βιῶσαι); 07-73 (you did good, another received it — to seek a "third thing" (fame, return) is folly); 08-01 (the good — only what makes one just, temperate, brave, free; all else is no good); 08-10 (pleasure is no good: the sage never repents a missed pleasure); 08-19 (a human is not "for pleasure" — the notion will not bear such a τέλος); 09-42 (the wage of a kindness is the act itself: the eye demands no recompense for seeing); 12.27.

In 02-05 the doctrine is given a closing rhetorical formulation: ὁρᾷς πῶς ὀλίγα ἐστίν, ὧν κρατήσας τις δύναται εὔρουν καὶ θεουδῆ βιῶσαι βίον — "see how few things one must master in order to live a smoothly-flowing, god-fearing life." "A few things" = the four virtues (σεμνότης, φιλοστοργία, ἐλευθερία, δικαιότης) + freedom from the passions + the absence of murmuring against fate (amor-fati). This narrow list is the "sufficient" for eudaimonia. Linked to dichotomy-of-control: only virtue is in "what is up to us," and only virtue is what is needed; a happy dependence on the external is therefore ruled out not as a sub-ideal, but as a category error.

In 03-06 the thesis is cast as a decision-procedure: "is there anything better (κρεῖττον) than justice, truth, temperance, courage, and the self-sufficiency of reason? If not — give place to nothing else." The external (pleasure, wealth, power, praise) is declared ἑτερογενές — "of another kind" than the good of reason, and to set it alongside is οὐ θέμις. The sharp addition: the external, once granted even a slight value-as-good, "suddenly takes command" (κατεκράτησεν ἄφνω) — which is why only an all-or-nothing stance is admissible.

In 03-08 the thesis is applied to the length of life: fate never catches the purified soul's life ἀσυντελῆ (unfinished), "as one would say of a tragic actor who left before playing out his part." A good life is whole at any moment, because completeness is a matter of virtue, not of span; the fear of "dying too soon" is dissolved. (Lifespan is an indifferent.)