Sensitivity in the depth-psychology corpus does not resolve into a single conceptual domain; it operates simultaneously as a spiritual virtue, a neurobiological parameter, a developmental capacity, and a clinical liability. The Taoist I Ching traditions treat sensitivity (hexagram 31) as a metaphysical principle: authentic sensing arises from the mind of Tao, not from the human mentality, and when sensitivity is true it enables yin and yang to commune rather than dichotomize. In sharp contrast, the neurobiological and trauma-focused literature—Kandel, Ogden, Bowlby, Siegel, Lanius—construes sensitivity as the threshold at which the nervous system registers and responds to stimulation, a parameter that is shaped by constitutional factors, attachment history, and learned fear. Kandel’s work on Aplysia establishes sensitization as the synaptic correlate of learned arousal, showing that threat experience lowers response thresholds across virtually all stimulus modalities. Bowlby adds the crucial observation that individual differences in perceptual sensitivity to emotionally charged stimuli are systematic and bidirectional: some persons are constitutionally primed to heighten, others to suppress, sensory registration of threat. Lanius and Ogden locate sensitivity at the intersection of trauma, window of tolerance, and dysregulation. Clinical sub-literatures extend the term to anxiety sensitivity (Feinstein), interoceptive sensitivity (Herman, Lovelock), and maternal sensitivity in attachment (Lanius). The central tension runs between sensitivity as a gift—the condition of authentic perception—and as a wound, the residue of overwhelm.