The cosmos is a single living being, pervaded by a single pneuma and a single Logos. All its parts are bound by sympathy (συμπάθεια): a movement in one resonates through all. Rational beings share in this unity at the highest level — through their common intellect (TERMnous), which is a TERMportion of the cosmic Logos. Every separation, therefore — between human and human, between human and nature — is illusory: each is a part (μέρος / μέλος, "member" or "limb") of a single body.

SVF II 473, 528, 532, 546 (the doctrine of συμπάθεια and of the pneumatic continuum); 1027 (the cosmos as a living being); DL VII 138–143; LS 47, 54. In Marcus the doctrine recurs as a leitmotif: Med. 04-40 (the world as one living being, one soul); 04-45 (harmonious co-ordination, a wonderful kinship); 04-46 (the Logos governing the Whole; Heraclitus); 05-08; 05-13; 05-21 (honour the mightiest in the cosmos — that which governs all); 05-24 (you are the tiniest part of the single substance); 05-32 (the reason pervading all substance); 06-01 (the single substance of the Whole, obedient to the one Logos); 06-09 (all is by the nature of the Whole; no other nature without or within); 06-25 (the simultaneity of all processes in the One-and-Whole — from microcosm to macrocosm); 06-35 (human reason is shared with the gods: one λόγος pervades gods and humans); 06-36 (all proceeds from a single source — the common ἡγεμονικόν); 06-37 (all of one kin and one form, ὁμογενῆ καὶ ὁμοειδῆ); 06-38 (all interwoven: τονικὴ κίνησις, σύμπνοια, unity of substance); 06-42 (all cooperate to one outcome); 06-43 (different, yet cooperating to one end); 06-45 (what happens to each benefits the Whole); 06-58 (nothing will befall you contrary to the reason of the common nature); 07-09 ("all things are interwoven, and the bond is holy"; the hymn of ones — one cosmos, god, substance, law, logos); 07-10 (matter into the substance, cause into the Logos of the Whole); 07-19 (bodies in the torrent — yet "connatural with the Whole" and cooperating with it, as members with one another); 07-23 (the one substance as wax: shapes succeed, the mass is one); 07-25 (out of the substance of some things — others, that the world may be ever young); 07-48 (the view from above: the all-mingled — "an order composed of contraries"); 08-18 (what dies does not fall outside the κόσμος — nowhere to fall: the world contains all); 08-34 (whoever cuts himself off — like a severed hand outside the body; yet a human can grow back); 08-52 (not to know what the κόσμος is is not to know where you are); 08-54 (to think-with the all-embracing νοερόν; the intelligent power diffused everywhere); 09-08 (one intelligent soul parcelled among the rational; one earth, one light, one air); 9.1; 09-09 (all akin strives toward the akin — συμπάθεια even among the stars, separated by space); 09-22 (the ἡγεμονικόν of the Whole — "remember whose part you are": one's place in the cosmic unity); 09-39 (ὡς ἑνὶ σώματι — it does not befit the part to blame what is done for the sake of the Whole); 12.30.

In 02-01 this doctrine is the load-bearing ontology of the argument: if all human beings are particles of a single Logos, then mutual counter-action is the self-fission of the whole. The body-images (body-parts, cooperation) are the anthropomorphic expression of cosmic unity: rows of teeth, eyelids, and hands cooperate because they are one body — and so do human beings, because they share one Logos. See oikeiosis (the ethical correlate) and view-from-above (the exercise that makes the unity intuitively evident).