Neural integration, as treated across the depth-psychology and neurobiological corpus housed in this library, names a cardinal organizing principle: the linkage of differentiated elements — neural circuits, psychological states, relational fields, temporal self-states — into a functional, harmonious whole. Daniel Siegel, whose voice dominates this conceptual territory, advances integration as the central mechanism of mental health, self-regulation, and developmental flourishing, articulating it through the FACES framework (flexible, adaptive, coherent, energized, stable) and situating it topographically within the connectome, the prefrontal regions, the corpus callosum, and the hippocampus. The critical tension the corpus sustains is between differentiation and linkage: too much linkage without differentiation collapses into rigidity, too little yields chaos — a dyadic polarity that maps onto psychopathology with genuine diagnostic precision. Allan Schore locates earlier neurobiological groundwork in orbitofrontal ontogeny and monoaminergic systems, while Gilbert Simondon contributes a philosophical dimension, treating integration and differentiation as transductive processes intrinsic to the living being’s ontogenesis. Evan Thompson’s enactivism provides a systems-theory backdrop through self-organization and emergence. What distinguishes this corpus from standard neuroscience is precisely the claim — argued most insistently by Siegel — that impairments to neural integration are impairments to selfhood, and that interpersonal relationship is both the medium through which integration is cultivated and a domain of integration in its own right.