The tripartite psyche — the division of the soul into three functionally distinct regions — constitutes one of the most persistent and contested structural claims in the depth-psychological tradition. Its primary ancient locus is Plato’s Republic, where the psuche is partitioned into the logistikon (rational), the thumoeides (spirited), and the epithumētikon (appetitive), a schema Hobbs, Lorenz, and Nussbaum each examine with philosophical precision, noting how the tripartition organizes Platonic ethics, education, and political theory. The tradition transmits this structure through Neoplatonism into Paracelsian alchemy — where Hillman traces the tria prima of body, soul, and spirit — into Christian asceticism, where the Philokalia’s tripartite soul of intelligence, incensive power, and desire becomes the battleground for demonic and divine forces alike. Freud’s own tripartite division of id, ego, and superego is recognized by Edinger as a modern analogue to Plato’s schema, though not directly derived from it. Jung’s psychology occupies a distinctive position: Hillman insists that Jung’s base is a tripartite ontology — neither matter nor mind but soul as tertium — a reading that grounds archetypal psychology’s entire methodological orientation. The most significant tensions in the corpus concern whether the tripartition is a stable descriptive anatomy or a dynamic, contestable heuristic, and whether its third term (thumos, soul, salt) is properly honored or structurally suppressed by the dominant rational-irrational binary.