Within the depth-psychology corpus, hexis occupies a structurally pivotal position at the intersection of Stoic natural philosophy, Aristotelian psychology, and the broader question of how enduring dispositions relate to action, virtue, and psychological change. The term designates a settled, scalar condition of pneumatic tension in Stoic thought — a kind of tonic holding-together that distinguishes coherent entities from mere aggregates, and that underlies the graduated hierarchy of nature from stones (unified by hexis alone) through plants (governed by phusis) to animals and rational beings. Brad Inwood’s sustained analysis is the dominant voice here, demonstrating that the Stoic mind harbours multiple powers each constituted as a hexis, and that active impulse itself is generated by such a disposition rather than being a mere momentary event. Margaret Graver sharpens a crucial distinction: Stoics differentiated hexis as a scalar condition (admitting more or less) from diathesis as a nonscalar one, reversing the Aristotelian priority wherein hexis was the more stable term. Nussbaum, reading Aristotle, underscores the contrast between hexis as latent, inactive potentiality and energeia as its actualization — a distinction with direct consequences for understanding vulnerability, impediment, and the fragility of the good life. The term thus bridges metaphysics of soul, ethics of character, and the philosophy of action.