The term ‘biting’ traverses the depth-psychology corpus along three distinct axes that only partially intersect. In the I Ching commentarial tradition — spanning Wilhelm, Wang Bi, Huang, and the Taoist interpreters — biting is the central operative metaphor of Hexagram 21 (Shi He, ‘Biting Through’), where it signifies the forceful, clarifying act of removing obstruction: juridical, moral, and alchemical. Here biting is not aggression but resolution, the mouth closing upon what impedes union. A second axis runs through Kleinian object-relations theory, where Melanie Klein’s observation of infants biting the nipple with apparent pleasure introduces the problem of oral sadism and its relation to love, envy, and the constitution of the ‘good’ and ‘bad’ breast. This is biting as the earliest ambivalent meeting of drive and object. The third axis is neurobiological: Panksepp distinguishes ‘quiet-biting attack’ — predatory, instrumentally calm — from affective rage-attack, a dissociation with significant implications for understanding aggression as a multi-systemic phenomenon. Across all three registers, biting marks a threshold: between obstruction and resolution, between pleasure and destruction, between predation and rage. The term thus condenses questions of agency, orality, punishment, and the ambivalent sources of desire that animate depth psychology’s core preoccupations.