Within the depth-psychology corpus, Lucifer functions not as a simple synonym for the Christian Devil but as a densely layered symbolic figure whose primary valence is the ‘light-bringer’ — the Phosphoros or Eosphoros of classical tradition, he who carries the morning star. Jung establishes the conceptual ground: Lucifer stands in a compensatory, shadow-relation to Christ, embodying what the trinitarian formula excludes — matter, darkness, the earth-bound pole of the God-image. In alchemical hermeneutics, particularly in the Mylius tradition cited repeatedly in the Collected Works, Lucifer and Mercurius are near-equivalents; the purification of Mercurius precipitates Lucifer’s fall from heaven, disclosing how closely illumination and perdition interpenetrate. Edinger’s Anatomy of the Psyche crystallizes this double valence: Lucifer is simultaneously the stella matutina, the evening and morning star, and the figure whose light-bearing function degenerates — in von Franz’s gloss on Jung — into the ‘father of lies’ when the lumen naturae is perverted by propaganda and collective inflation. Hillman inflects the term differently, situating Lucifer in the icy, post-Dantean Ninth Circle as an image of radical betrayal that the therapist must meet with corresponding coldness rather than redemptive warmth. Campbell introduces the Grail tradition’s ‘neutral angels,’ connecting Lucifer’s refusal to bow to man with the question of spiritual pride. Woodman reads Lucifer as the seductive animus-force that captures the puer-identified puella. Across these positions, Lucifer marks the threshold where illumination, shadow, and archetypal evil converge.