The term ‘interoceptive’ names a domain that depth-psychology and affective neuroscience have progressively recognized as foundational to the very constitution of subjective experience. Historically circumscribed to visceral sensation by Sherrington’s original coinage, the concept was systematically enlarged by A.D. (Bud) Craig, whose lamina I spinothalamocortical research repositioned interoception as the sense of the physiological condition of the entire body — the missing afferent complement to the efferent autonomic nervous system. Craig’s insular cortex findings gave the term its modern neurobiological anchor. Barrett’s constructivist account extended it further, framing interoception as a whole-brain predictive process in which body-budgeting regions and primary interoceptive cortex jointly generate emotion. Khalsa, Khoury, and allied researchers pressed the clinical implications, mapping how interoceptive accuracy, attention, self-efficacy, and insight each constitute distinct measurable dimensions whose disruption underlies psychiatric conditions from depression and panic disorder to addiction. Farb’s mindfulness research demonstrated cortical plasticity in interoceptive representation following contemplative training, while Lovelock, Herman, and Naqvi traced interoceptive signals through addiction circuits, linking insula-mediated body-state representations to craving and substance use. The persistent tensions in the field concern taxonomy — whether accuracy, sensibility, and insight are truly dissociable — and methodology — whether subjective report, heartbeat-detection tasks, and neuroimaging converge on a unitary construct. For depth-psychological work the stakes are clear: interoception is the substrate where soma becomes meaning.