The term ‘oceanic’ occupies a charged and contested position within depth-psychological literature, functioning simultaneously as a phenomenological descriptor, a diagnostic category, and a philosophical problem. Its modern clinical lineage begins with Freud’s engagement in Civilization and Its Discontents with Romain Rolland’s account of the ‘oceanic feeling’ — that sense of boundless unity with the universe — which Freud interpreted reductively as a regression to primary narcissism or intrauterine merger, a residue of pre-egoic undifferentiation. This foundational ambivalence — is the oceanic a pathological dissolution or a legitimate mode of knowing? — reverberates throughout the corpus. Mark Epstein, writing from a Buddhist-psychoanalytic perspective, distinguishes the oceanic from genuine meditative insight, arguing that Freud misidentified a God Realm experience for the deeper, egoless condition the Buddha described. Stanislav Grof and Roland Griffiths, working within transpersonal and psychedelic research frameworks, operationalize the oceanic as ‘oceanic boundlessness,’ a measurable dimension of altered-state phenomenology. James Hillman gestures toward the oceanic imagination as a primordial depth — the ‘hidden deeps’ of the titanic Urwelt — while Moore reads it as the claustrophobic pull of the undifferentiated maternal unconscious. Richard Tarnas situates the oceanic within the Neptune complex, associating it with mystical union, boundary dissolution, and the surrender of egoic control. The term thus marks a persistent fault line between regression and transcendence, between pathology and gnosis.