The ascent of union: from elements to stars. Marcus builds a physical ladder of "striving toward the kindred" (πρὸς τὸ TERMὁμογενές σπεύδει). At the bottom, the simple tending of the elements: the earthy toward earth, the fluid flowing together, air toward air; fire rises, yet readily "co-kindles" (συνεξάπτεσθαι) with the fire here below. Higher up, ensouled beings: even the non-rational have swarms, herds, the rearing of nestlings, "something like love" (οἷον ἔρωτες), for soul (ψυχή) has appeared and the "drawing-together" (τὸ συναγωγόν) is intensified. Higher still, the rational: DOGMAstates, friendships, families, assemblies, treaties. At the summit, what is one even in separation: DOGMAthe stars, among which a συμπάθεια holds across distance. The more perfect the nature, the stronger its pull to fuse with the TERMakin.
The paradox of the rational. The climax is bitter: the intelligent beings alone have "now forgotten" (ἐπιλέλησται) the mutual striving; in them alone the "flowing-together" (τὸ σύρρουν) is not seen. Yet nature has its way: "though they flee, they are overtaken, for TERMnature prevails (κρατεῖ ἡ φύσις)." The closing image seals it: you will sooner find earth touching nothing earthy than MOTIFa man severed from a man (ἄνθρωπον ἀνθρώπου ἀπεσχισμένον) — cf. the severed hand of 8.34 and the physical premise of 9.8 (one intelligent soul for all). The governing discipline is action: DOGMAsociability here is not an ideal but a physical law, and to shun it is as unnatural as for water not to flow.