In the depth-psychology corpus, ‘Opening’ operates simultaneously as a structural, temporal, and metaphysical concept, traversing registers from archaic Greek etymology to contemporary clinical practice. The most concentrated treatment appears in the etymological recovery of kairos — the penetrable aperture through which an archer’s shaft must pass at precisely the right moment — a motif developed by Onians and elaborated with mythopoeic force by Hillman, who links the opening in the warp-threads of fate to the puer figure’s capacity for decisive, irreversible breakthrough. Here, Opening is never passive: it is constitutively time-bound, demanding readiness and power simultaneously. Giegerich radicalizes the concept in an entirely different register, arguing that in the soul’s inverted world, the deterrent ‘No!’ is itself the only opening — the entrance that negates ordinary thresholds. Frank, drawing on Levinas, employs ‘half opening’ to describe the ethical aperture that suffering creates between self and Other, a space simultaneously too small and the only passage toward the inter-human. Woodman and Hillman both invoke the opening as visionary passage beyond psychological enclosure, while ACT clinical literature transposes the term into the therapeutic goal of ‘opening up’ as defusion and acceptance. Across these trajectories, the term consistently marks the threshold condition: a narrow, time-sensitive, high-stakes passage constitutive of transformation.