Transformation, change of state. For the Stoics, μεταβολή is the fundamental process of the cosmos's existence: fire becomes air, air water, water earth — and back again (the so-called κυκλικὴ μεταβολή, the cyclical transformation of the TERMelements). Every particular thing is only a temporary configuration in this flow: birth is the transformation of matter into a compound body (συγκρίμα), death is the transformation of the compound back into the elements. Death is therefore not an ontological "loss": nothing disappears, everything passes over.

SVF II 413–425 (transformations of the elements); II 596–632 (the role of pneuma in transformations); II 596 (the doctrine of the cycle, κύκλος); DL VII 142; LS 47, 52. The Heraclitean background (to which Marcus himself appeals): Heracl. fr. 30, 36, 76 DK. In Marcus μεταβολή is a leitmotif: Med. 2.3; 2.17; 4.3.8 ("the substance of the universe is a river"); 4.36 ("everything that exists is the seed of what will come to be from it"); 6.15; 7.18; 9.19; 9.28; 12.21.

In 02-03 μεταβολή executes the final argumentative turn: "the cosmos is preserved both by the changes of the elements and by the changes of compound bodies." My individual death, that is, is not a contradiction to the cosmos but its mode of continuation. This thought is the principal Stoic answer to the fear of death: what we fear is the very process that produced us. See meditatio-mortis (the exercise) and the doctrine amor-fati (acceptance of what happens).