The term ‘vessel’ occupies a remarkably dense conceptual position across the depth-psychology corpus, functioning simultaneously as alchemical apparatus, archetypal symbol, psychological metaphor, and ontological category. Jung establishes the foundational polarity: the vas hermeticum is at once the container of the opus and, paradoxically, identical with its contents — ‘the vas is often synonymous with the lapis, so that there is no difference between the vessel and its content.’ This reflexive identity, in which container and contained collapse, recurs throughout the literature as a signature of transformative processes. Neumann extends the vessel into the Archetypal Feminine, reading the body-vessel as the primordial image through which psychic contents are experienced as ‘inside’ a maternal enclosure — womb, ark, ship, cradle, and coffin all participate in the same symbolic economy. Hillman, working from alchemical texts directly, foregrounds the vessel’s disciplinary function: its walls guard the nascent work, prevent premature escape of volatile contents, and impose the secrecy essential to psychological gestation. Von Franz traces the motif from Zosimos through medieval mysticism to the Grail, emphasizing the vessel’s capacity for visionary perception — it is not merely a container but an organ of revelation. Giegerich introduces a critical tension, noting how ‘personness serves as the by definition unaffected containing vessel,’ a domesticating function that may itself foreclose genuine psychological depth.