Sol — the sun, gold, the masculine principle, and the ego’s luminous field — occupies a structurally indispensable position across the depth-psychological corpus. In Jung’s alchemical studies, Sol operates at multiple registers simultaneously: as the prima materia awaiting transformation, as the gold tincture that is the goal of the opus, and as the ego-consciousness whose brilliant but partial light casts its own shadow. Jung’s Mysterium Coniunctionis establishes the decisive tension: Sol must unite with Luna in the coniunctio to produce the lapis, yet Sol carries sulphurous, corrupting properties that imperil the work. The sol terrenus distinguishes an earthly, preliminary phase from the philosopher’s gold, reminding the reader that solar consciousness remains raw material, not consummation. Edward Edinger, following Jung, explicates Sol’s dual nature — its destructive, overwhelming luminosity on one hand, its redemptive illumination on the other — while grounding both aspects in clinical and mythic phenomenology. Thomas Moore, reading Ficino, positions Sol within a polytheistic psychic ecology: the sun-spirit is one planetary intelligence among several, its drying, purifying tendency potentially corrected by Jupiter and Venus. Abraham’s alchemical dictionary anchors the symbolic pairing Sol–Luna in the chymical wedding tradition. Together these voices establish Sol not as a simple symbol of consciousness but as a dynamic force whose integration with its opposite constitutes the central drama of the individuating psyche.