The hippocampus occupies a structurally and functionally central position across the depth-psychology corpus, appearing most consistently as the neural substrate of explicit, declarative, and spatial memory. Kandel’s sustained research programme—spanning cellular electrophysiology, place-cell mapping, and molecular biology—provides the corpus’s most detailed treatment, tracing the hippocampus from its pyramidal-cell architecture through long-term potentiation to its role in spatial cognition and age-related memory decline. Milner’s classical work on H.M. establishes the hippocampus as necessary for the consolidation of new explicit memories, a finding that anchors the entire field. The trauma literature, represented by Lanius and Ogden, shifts the register dramatically: here the hippocampus appears as a structure diminished by chronic stress, its volumetric atrophy and functional deficits mediating the fragmented, dysregulated memory characteristic of PTSD, with neurogenesis offering a potential therapeutic vector. Burnett adds an evolutionary dimension, arguing for the co-development of hippocampal navigation and olfactory memory systems. Panksepp and Mohandas extend the hippocampus into affective neuroscience and altered states, connecting it to the SEEKING system’s theta rhythms and to meditation-induced shifts in perfusion. Across these positions, a productive tension persists between the hippocampus as a site of constructive spatial and episodic encoding and as a structure rendered vulnerable by overwhelming experience.