A command to the imagination. The passage opens with TERMΦαντάζου — "picture to yourself," the verb from which φαντασία is formed. It is a rare case in Marcus where the exercise is set as work with an image: not "reason it out" but "imagine" — and keep the image ready against the hour when you begin to murmur yourself.

The piglet and its silent double. The first image is deliberately coarse: the man who TERMgrieves is like a χοιρίδιον at the sacrifice, kicking and squealing (ἀπολακτίζοντι καὶ κεκραγότι). But the force of the passage lies in the second sentence: ὅμοιος καὶ ὁ οἰμώζων ἐπὶ τοῦ κλινιδίου μόνος σιωπῇ — "like it too is the man who laments on his bed, alone and in silence." Marcus closes the loophole: restraint does not save. The squealing piglet and the silently grieving philosopher differ in volume, not in position — both are kicking in the same cord. Both nouns are diminutives (χοιρίδιον, κλινίδιον), which rhymes them together.

ἔνδεσις. A rare word — "a being bound, a tether." Not "fate" or "necessity" as abstractions, but literally the thing the sacrificial piglet is tied with. And so the second half of the passage reads as a continuation of the image rather than a turn to theory.

The one difference. DOGMAμόνῳ τῷ λογικῷ ζῴῳ δέδοται τὸ ἑκουσίως ἕπεσθαι — "to the rational animal alone it is given to follow willingly," τὸ δὲ ἕπεσθαι ψιλὸν πᾶσιν ἀναγκαῖον — "but to follow bare is a necessity for all." The choice is not between going and not going but between two ways of going. The classic formulation of the same is Cleanthes', in Seneca's rendering: ducunt volentem fata, nolentem trahunt. Cf. 10.25 (the griever is a runaway slave) and 6.42 (all cooperate, even the one who resists). The governing discipline is desire, the sustaining one assent.