Some things are up to us (τὰ ἐφ' ἡμῖν); others are not (τὰ οὐκ ἐφ' ἡμῖν). Up to us are opinion, impulse, desire, aversion — in a word, whatever is our own doing. Not up to us are the body, property, reputation, office — in a word, whatever is not our own doing. Good and evil lie only in what is up to us; in everything else there is neither good nor evil.

Canonically formulated by Epictetus at the opening of the Enchiridion (Ench. 1). The formula does not occur as such in Marcus, but pervades the whole corpus: 05-05 (much is in your power — sincerity, gravity, endurance); 05-19 (things do not touch the soul; it troubles itself); 05-20 (the obstructor becomes indifferent to me, like the sun); 05-25 (another sins against me — his affair; I keep my own disposition); 05-26 (the ruling part is unmoved by the motions of the flesh); 05-29 (if they do not let you live as you ought — "smoke, and I depart"); 05-33 (what is prized in life is empty; guard only the ruling part); 05-34 (you can always "flow well" if you judge and act rightly); 05-35 (not my vice, no harm to the common — why be disturbed?); 06-08 (the ruling part makes all that happens appear to it as it wills); 06-20 (it is in our power to draw aside, without suspicion or hatred); 06-32 (the mind's activities are in its power, ἐπ’ αὐτῇ; all else indifferent); 06-41; 06-50 (impulse with a reserve-clause — not reaching for the impossible); 06-51 (the good of the rational being lies in his own action, not another's or in sensation); 06-52 (hold no opinion — the soul is untroubled); 07-02 (what is outside my mind is nothing at all to my mind; rekindling the impressions is in your power); 07-14 (not to take what happened for an evil is in my power; without that there is no harm); 07-15 (whatever anyone does — I must keep my own colour, like the emerald); 07-16 (the ruling part needs nothing, ὅσον ἐφ’ ἑαυτῷ, unless it makes a need for itself); 07-33 (to the mind — γαλήνη by walling off; to the suffering parts — the right to declare); 07-44 (Plato, Apol. 28b: life/death are not in the act's reckoning, only justice); 07-58 (leave others' "turns" to their owners; be yourself about how to use the event); 07-62 (not to need the approval of those whose ruling part is corrupted); 07-71 (flee your own κακία (possible), not others' (impossible) — the "mine/not-mine" mapping); 08-04 (others' acts are not up to me — "they will do the same, though you burst"); 08-07 (ὀρέξεις and ἐκκλίσεις confined to τὰ ἐφ’ ἡμῖν); 08-08 (no leisure to read — but to curb pride, pleasure, fame: all ἔξεστιν); 08-17 (ἐπὶ σοί or ἐπ’ ἄλλῳ — in either case there is no one to blame); 08-28 (κρίσις, ὁρμή, ὄρεξις, ἔκκλισις — all ἔνδον; no evil ascends); 08-29 (νῦν ἐπ’ ἐμοί — now it is in my power to keep the soul clean); 08-32 (the external cannot hinder acting δικαίως, σωφρόνως, εὐλογίστως); 08-41 (τὰ τοῦ νοῦ ἴδια no one impedes — not fire, not tyrant; the mind-sphere); 08-47 (not the thing but your judgment troubles you — and to wipe it out is in your power); 08-49 ("you are reviled" is reported; "you are harmed" is not reported); 08-55 (vice holds by assent and is undone by decision — "the moment you will"); 08-56 (another's προαιρετικόν is not up to me — like his breath and flesh); 09-13 (trouble is not outside (ἔξω) but within, in the ὑπολήψεις: "I threw it out"); 09-15 (things "outside the doors" are mute, pronouncing nothing of themselves — τὸ ἡγεμονικόν judges); 09-20 (another's fault — "leave it there where it is": it is not up to me and not my evil); 09-31 (ἀταραξία toward the "external cause," δικαιότης toward "your own cause": the line of what is up to us); 09-32 (what troubles you "lies in the ὑπόληψις" — it can be removed by judgement); 09-40 (the reform of prayer: ask not for the thing but for freedom from fear, desire and grief — and the gods lend a hand even in τὰ ἐφ’ ἡμῖν); 09-41 (the διάνοια, sharing the motions of the poor flesh, keeps its own good and ἀταρακτεῖ); 10-03 (to make what happens bearable "lies with your own ὑπόληψις" — the boundary of the endurable runs through judgement); 10-11 (justice for what is his own, the nature of the Whole for all else; others' words are "not even taken into his mind"); 10-32 (πᾶν δὲ τοῦτο ἐπὶ σοί· τίς γὰρ ὁ κωλύων; — to be simple and good is achievable precisely because it bears not on reputation but on ones own doing); 10-33 (νοῦς and λόγος pass through all that resists: "the remaining hindrances belong either to the poor dead body, or, apart from judgement, do no evil"); 11-11 (a reversal of direction: things do not come to you — it is you who "in a manner" go to them, and pursuit and flight are alike a movement toward the object; what is prescribed is not the suppression of the impulse but the falling silent of the κρῖμα); 11-13 (ὄψεται — one word holds both halves: another’s contempt is his affair, my not deserving it is mine); 11.37; 12.22. It goes back to the classical Stoic doctrine of freedom (ἐλευθερία) as unattachment to externals. See further 11-16: things put no opinion of themselves into us and do not come to us — "they stay unstirring, and it is we who beget the verdicts about them." From the Epictetan excerpts: 11-36 (Λῃστὴς προαιρέσεως οὐ γίνεται — there is no brigand of the will, because there is no purchase on it) and 11-37 (ἐκκλίσει πρὸς μηδὲν τῶν οὐκ ἐφ’ ἡμῖν χρῆσθαι — to use aversion toward nothing that is not up to us). In Book XII — 12-03 (the line is drawn inside the "I" itself: the first two components are yours μέχρι τοῦ ἐπιμελεῖσθαι δεῖν, the third is κυρίως σόν). Cf. also 12-08 (πῶς οὐδεὶς ὑπ’ ἄλλου ἐμποδίζεται, as one item in the checklist); 12-22 (the decisive addition to "everything is opinion": καὶ αὕτη ἐπὶ σοί). And 12-25 (the unanswered question that is itself the dichotomy: τίς οὖν ὁ κωλύων ἐκβάλλειν; — who, then, is preventing you from throwing the opinion out?). In Books I–IV the dichotomy is drawn above all through another's soul: 02-06 (lodging one's happiness in the souls of others), 02-08 (not to watch what goes on in another's soul); and through the impossibility of hindrance: 02-07, 02-09 (οὐδεὶς ὁ κωλύων), 02-11 (ἐπ’ αὐτῷ τὸ πᾶν ἔθεντο), 03-06 (what falls to one's lot lies outside choice), 04-03 (things do not touch the soul, it stands outside them, and the troubles come from the inward opinion alone), 04-39.

The modern literature distinguishes a "strict" and a "soft" version of the doctrine: does "what is up to us" cover only acts of judgment and assent (the narrow reading, the TERMhegemonikon) or actions as well (the broader reading)? Marcus apparently holds the narrow version.