Physiological metaphor occupies a distinctive and theoretically charged position across the depth-psychology corpus, functioning not merely as decorative rhetoric but as a structural mechanism through which inner states, psychological processes, and even cosmic orders are rendered intelligible. The range of treatments is remarkable. In the archaic Greek materials examined by Jaynes, Padel, and Caswell, physiological terms such as thumos, kradie, and phrenes are not metaphors applied to pre-existing concepts but rather the original organs of psychic experience — the body generating the very vocabulary of interiority. Rank traces this logic forward into anatomical nomenclature itself, showing that Western medical terminology preserves cosmological and mythological projections from ancient Eastern systems. Porges, writing from neurophysiology, reclaims the term with precision, proposing that the vagal system constitutes a ‘physiological metaphor’ for emotional regulation — here the body is not merely a source domain for psychological language but actively models the structure of affect. Damasio approaches the same territory through the skin and viscera, illustrating how popular idioms unwittingly encode physiological truth. The deep tension in the corpus runs between literalism and metaphoricity: pre-Aristotelian thinkers, as Padel shows, did not distinguish them, using bodily images as explanations rather than as figures of speech. This unresolved boundary — where the somatic ends and the symbolic begins — is what makes physiological metaphor indispensable to depth-psychological inquiry.