Aporrhoia literally means "an effluence," "that which flows out from." In Stoic theology it is one way of describing the bond between the rational human soul and the cosmic Logos: the human being is not "god's creation" in the sense of something produced from outside, but an "effluence" — a stream that has separated off from a primary river but is ontologically of one and the same matter with it. The metaphor of river and outflow works more accurately here than that of creator and creation: between source and stream there is no ontological break, only a local distinction.

SVF I 135, 495 (the doctrine of the soul as ἀπόσπασμα τοῦ θεοῦ, a kindred notion); II 633, 774 (the pneumatic contact between the human soul and the cosmic pneuma); Epict. Disc. 1.14.6 ("you are a fragment of god"); 2.8.10–14. The term ἀπόρροια appears in Marcus only at Med. 2.4; the kindred formula (μετοχὴ νοῦ καὶ θείας ἀπομοίρας) occurs at Med. 2.1 and 12.26.

In 02-04 ἀπόρροια operates within a self-positioning question: "of what governor of the cosmos are you an effluence?" (τίνος διοικοῦντος τὸν κόσμον ἀπόρροια ὑπέστης). This formula is paired with μετοχὴ νοῦ καὶ TERMθείας ἀπομοίρας from 02-01 and describes the same relation, but through the image of the stream rather than the portion. The nuance differs: ἀπομοῖρα is a portion set apart (like a piece broken off from a whole loaf); ἀπόρροια is a flow that has split off (like a brook from a river). Both images underscore consubstantiality with the cosmic reason — the first through discreteness, the second through continuity. See also unity-of-cosmos (the ontological ground) and TERMpronoia (the principle of governance).