Place in the book. After the developed morning exhortation of 05-01, a one-line maxim: the discipline of assent in pure, compressed form. Marcus states not an argument but an observation-cum-technique.

The technique. Two verbs — ἀπώσασθαι ("to push away") and ἀπαλεῖψαι ("to wipe out," as one erases writing) — describe work not on the event but on the TERMimpression of it. What disturbs is not the thing but the assent to a troublesome (ὀχληρά) or alien (ἀνοίκειον, "not one's own") φαντασία; withdraw that assent, and TERMγαλήνη remains. Cf. the fuller formula of Med. 9.7: "wipe out the impression, check the impulse, quench the desire."

"How easy." The key word is εὔκολον. The Stoic wager: assent is what is up to us, and so calm is attainable at once and "easily"; it is we who make it hard, by holding on to the judgement. "Immediately" (εὐθύς) stresses that between the erasing of the impression and the calm there is no gap.

γαλήνη. The word is maritime — the smooth surface of a windless sea. This is a positively felt stillness, not merely the absence of anxiety (ἀταραξία) or freedom from the passions (ἀπάθεια). It is kin to the image of the clear sky: clear away the clouds of false assents, and the sky (or the sea) returns of itself to clarity.

The discipline. Assent: φαντασία → judgement → γαλήνη. Parallels — Med. 9.7 (the full formula of the three disciplines); on the "calm" of serenity — 12.22.