Within the depth-psychology corpus, ‘sadistic’ occupies a theoretically dense intersection of drive theory, character structure, social psychology, and developmental pathology. Freud’s foundational treatment in the Three Essays establishes the sadistic impulse as inseparable from masochism — a paired perversion rooted in the aggressive component of the libido, phylogenetically traceable to cannibalistic desire. Abraham elaborates this substrate through his meticulous staging of the anal-sadistic phase, positioning sadistic impulses as multiply sourced — oral, excremental, muscular — and intimately entangled with object-relations and their distortions. Fromm undertakes perhaps the most sustained socio-psychological rethinking of the term, relocating sadistic strivings from purely instinctual ground onto the terrain of character and freedom: sadism, in his account, is the dominant pole of a sado-masochistic structure arising where autonomy fails and the craving for symbiotic power takes hold. His analysis of Nazism renders sadistic character not a clinical aberration but a socially normative pattern among displaced classes. Horney, cataloguing its appearances in the arrogant-vindictive type, distinguishes sadistic trends from vindictiveness and links them to externalised self-torture and the neurotic pride system. Klein traces sadism to early oral and urethral-sadistic phantasies, grounding it in the paranoid-schizoid position and the infant’s destructive attacks on the breast. Rank offers an arresting mythological gloss, framing the archetypal sadist as one driven by the hatred of expulsion — the birth trauma incarnated in violence. Taken together, the corpus resists any single-axis account, oscillating productively between instinct, character, developmental phase, and cultural formation.