The single letter ‘S’ appears in the depth-psychology corpus not as a unified theoretical concept but as a bibliographic and indexical marker — a section-heading letter organizing concordances, glossaries, and indices across the major works of the tradition. Across Jung, Eliade, Campbell, Heidegger, Zimmer, and others, the passages grouped under ‘S’ constitute dense cross-referential terrain: alchemical terms (Sol, solutio, scintillae), psychological constructs (Self, shadow, schizophrenia, suggestion), Sanskrit and Pali technical vocabulary (samsara, samadhi, shunyata, skandha), mythological figures (Shiva, Saturn, Solomon), and ontological categories from Heidegger’s existential analytic (Selbst, Sorge, situation). What the concordance entry for ‘S’ reveals, paradoxically, is the breadth of the library’s comparative ambition: the same alphabetic section harbors alchemical Sol and Buddhist satori, Jungian Self and Heideggerian Sein. This co-presence is not accidental — it reflects the depth-psychological project’s synthetic drive, its insistence on mapping psychic life across cultures, languages, and historical epochs. The ‘S’ entries thus serve as a cross-section of the library’s methodological range, from Beekes’s etymological precision to Jung’s symbolic amplification to Eliade’s phenomenology of the sacred.