The term ‘Holy’ occupies a foundational yet contested position within the depth-psychology corpus, where it functions simultaneously as a phenomenological category, a theological attribute, and a psychological object of inquiry. Rudolf Otto’s 1917 treatise remains the conceptual lodestar: his analysis of the holy as a sui generis category—irreducible to rational or ethical predicates, expressing instead the ‘numinous’ as an inexpressible quality that elicits creature-feeling, awe, and self-abasement—supplies the vocabulary that Jung and his successors would repeatedly engage. Otto’s ‘mysterium tremendum et fascinans’ structures the emotional encounter with the sacred as something prior to, and generative of, doctrinal elaboration. Jung and Edinger transpose this phenomenological category into psychological idiom, treating the Holy Spirit as the dynamic, transformative third person of the Trinity whose indwelling in ‘creaturely man’ signals an epochal shift in the God-image. Von Franz extends this into alchemical territory, reading the Holy Ghost movements of the twelfth and thirteenth centuries as precursors of depth-psychological individuation. Benveniste’s linguistic archaeology of hierós traces the semantic evolution from ‘strong’ through ‘filled with divine influence’ to ‘sacred,’ grounding Otto’s phenomenology in philological evidence. The Orthodox corpus—John of Damascus, the Philokalia, Bulgakov—preserves the liturgical and theological register in which holiness is commanded imitation of divine perfection. The central tension runs between holiness as external, commanding otherness and holiness as an immanent, transformative interior process.