The four elements — fire, air, water, and earth — constitute one of the most generative structural symbols in the depth-psychology corpus, functioning simultaneously as a cosmological inheritance from pre-Socratic philosophy, an alchemical operational schema, and a psychological model of psychic wholeness. Jung’s decisive contribution was to read the quaternary arrangement of the elements as an archetypal system of orientation: correlating fire, air, water, and earth with the four psychological functions of thinking, feeling, intuition, and sensation, he argued that this fourfold schema always expresses a totality, particularly the totality of consciousness. Von Franz elaborated the ambivalence inherent in this structure, noting the perpetual alchemical vacillation between three and four — between Trinity and quaternary — and locating the inferior or fourth element as a gateway to the unconscious. Edinger applied the elemental schema clinically, finding in the alchemical injunction ‘separate the earth from the fire’ a precise instruction for differentiating concrete from symbolic reality. Arroyo extended the model astrologically, treating the four elements as fields of energy and modes of perception structuring human experience from birth. Plato’s Timaeus stands as the foundational philosophical text to which nearly all subsequent treatments return, establishing the geometrical derivation and cosmic proportionality of the four. Throughout the corpus the tension between three and four — between dynamic process and stable totality — marks the four elements as irreducibly paradoxical: simultaneously a map of completion and a site of ongoing psychic conflict.