Four beats, and always the same conjunction. Ἓν … μία … μία … μία, and each time κἄν ("even though"): light, substance, soul, intelligent soul. The form is deliberately monotonous — a series in which only the subject changes while the assertion stays put: what is one does not stop being one for being partitioned.

Why light is taken first. The sun's light is the one of the four about which it is obvious that a wall does not divide it: what is partitioned is not the light but its passage. The image sets the way to read the other three, and is therefore placed first; cf. 8.57, where the sun's rays are said to be not "poured out" but stretched (τάσις) — and the card MOTIFmind-as-light.

And a proviso that keeps the balance. Marcus does not claim that all parts are one: TERMπνεύματα and the insensate substrates are "foreign to one another" — ἀνοικείωτα, literally "not made kin, not appropriated." What holds them together is not kinship but two physical principles: τὸ ἑνοῦν ("the unifying," the Stoic ἕξις) and τὸ ἐπὶ τὰ αὐτὰ βρῖθον — "what inclines the same way," that is, weight. The unity of the lifeless is mechanical.

The difference the passage was written for. διάνοια δὲ ἰδίως — "but mind in its own way": it is not held from outside; it itself stretches (τείνεται) toward what is of a kind with it and stands together with it (συνίσταται). And the conclusion: οὐ διείργεται τὸ TERMκοινωνικὸν πάθος — "the social feeling is not partitioned off." The very κἄν that carried the first four beats is dropped here: for mind there are no partitions at all. Thus the physics of unity becomes the ground of DOGMAfellowship; cf. 12.26: a community not of blood but of mind. The governing discipline is assent, the sustaining one action.