Habituation occupies a distinctive niche within the depth-psychology corpus, functioning simultaneously as one of the most elementary forms of learning and as a conceptual boundary marker separating nonassociative from associative processes. Kandel’s neuroscientific account, developed through decades of work on Aplysia, renders habituation a paradigm case of synaptic plasticity: repeated stimulation progressively weakens synaptic efficacy, producing measurable behavioral attenuation that mirrors, at the cellular level, what classical learning theory had charted behaviorally. LeDoux sharpens the conceptual contrast by positioning habituation as a stimulus-repetition procedure suited to innate or preexisting sensitivities — a nonassociative complement to extinction’s associative logic — thereby opening therapeutic relevance for clinicians treating fear responses that lack a discrete learning history. Ogden’s sensorimotor framework introduces the orienting reflex as the phenomenological counterpart, framing habituation as the adaptive dimming of attentional vigilance to inconsequential stimuli, while insisting on the equally vital counter-capacity for resensitization. Across these positions, a productive tension emerges: habituation is celebrated as the simplest, most tractable form of memory modification, yet its very simplicity raises questions about its relationship to more architecturally complex forms of learning, long-term memory consolidation, and the survival imperatives that keep organisms perpetually responsive to novelty. The corpus treats habituation not as mere fatigue but as genuine, reversible learning with structural correlates.