Within the depth-psychology corpus, ‘concern’ operates across at least three distinct registers that intersect yet resist simple unification. Winnicott establishes the term’s most technically precise psychoanalytic meaning: concern is the developmental achievement whereby the infant integrates love and aggression, recognizes the mother as a whole person, and assumes responsibility for the destructive content latent in instinctual life. For Winnicott, concern is the affective foundation of guilt, reparation, constructive play, and all subsequent ethical life — a capacity that emerges prior to the Oedipal triangle and whose failure marks serious psychopathology. Heidegger deploys ‘concern’ (Besorgen) in an entirely different key: as the ontological term for Dasein’s characteristic manner of Being-in-the-world alongside ready-to-hand entities, grounded ultimately in the temporal structure of care (Sorge). This existential register treats concern not as an emotion but as the constitutive mode through which world discloses itself to a being whose Being is always already at issue. A third, biological register appears in Thompson’s reading of Jonas and Spinoza, where the organism’s minimal ‘concern’ to persist in being is identified with conatus — life’s immanent purposiveness. The tensions among these registers — developmental, ontological, biological — illuminate why ‘concern’ proves indispensable to any psychology that takes seriously the relationship between selfhood, world, and the claims of others.