Three parts — and a proviso easily missed. σωμάτιον, TERMπνευμάτιον, TERMνοῦς: two belittling diminutives and one full word. The triad is familiar — cf. 2.2 (σαρκία / πνευμάτιον / ἡγεμονικόν) and 6.32. But here the third member is called νοῦς, not ἡγεμονικόν, and the substitution is not idle: ἡγεμονικόν arrives further down, where the work of purification begins. The proviso runs: the first two are yours μέχρι τοῦ ἐπιμελεῖσθαι δεῖν — "so far as they must be cared for." Not "not yours": ownership is measured out by the duty of upkeep, which is more exact than the usual Stoic disdain of the body; cf. 7.16 and 8.56.
A sentence begun twice. The syntax here breaks, and not through a copyist: the period ὃ ἐὰν χωρίσῃς… runs off into a list of six members, loses its government — and Marcus starts again: ἐὰν χωρίσῃς, φημί, "if you separate, I say." This is the trace of live writing: the writer lost his way inside his own list and picked the thread up aloud. Such recoveries are rare in the Meditations, and they are the best proof that what we have is a notebook and not a treatise.
What exactly is separated off. The list is not casual; it covers every entrance for disturbance: what others do and say; one's own past deeds and words; the future, troubling one "as about to be"; the TERMnon-volitional (ἀπροαίρετα) in the body and in the breath grown together with it; and the "external circumfluent vortex" — δίνη, a word of Presocratic cosmology, in the atomists the very whirl out of which worlds are put together. The most unexpected item is the second: one's own past is separated off on the same terms as another's.
Three disciplines in three participles. TERMποιοῦσαν τὰ δίκαια καὶ DOGMAθέλουσαν τὰ συμβαίνοντα καὶ λέγουσαν τἀληθῆ — "doing what is just, willing what happens, speaking what is true." These are the disciplines of action, desire and assent, named in a row and without terminology; cf. 8.7, 9.6 and 11.37, where the same three are set out as school doctrine on Epictetus's authority. It is worth noting that the third member is put in terms of speech: assent is tested by what a man is prepared to say aloud — the very move Marcus unfolds in the next passage, 12.4.
The sphere. The quotation is introduced by οἷος ὁ Ἐμπεδόκλειος — "such as the Empedoclean [sphere]": the source is named while the word "sphere" itself is withheld, arriving only with the verse. In Empedocles the Σφαῖρος is a state of the cosmos; in Marcus it is a state of the mind, and the transfer is made in silence. He copied the same line at 8.41, and at 11.12 developed it without quoting, setting out the spoiling of the sphere as four distinct deformations; the card is MOTIFmind-as-sphere.
The close is not impassivity. The three adverbs of the ending rise in warmth: ἀταράκτως (untroubled), εὐμενῶς (kindly) and ἵλεως — a word of cultic language, "graciously," as one speaks of a god well disposed toward you. And it is referred to one's own TERMdaemon: to live out the remainder "graciously toward one's own genius." The end, then, is not numbness but being on good terms with the divine in oneself; cf. 5.27. The governing discipline is assent (the whole labour of the passage is χωρίζειν, separation), the sustaining one desire.