The term ‘Relational Prosthesis’ does not appear as an explicit, named construct within the candidate passages drawn from this segment of the depth-psychology corpus; no author deploys the phrase as a technical term. Nevertheless, the conceptual territory the term would occupy — the use of an external relational structure, whether person, institution, or therapeutic relationship, to supplement, scaffold, or compensate for a deficit in self-regulatory or attachment capacity — is richly if obliquely populated. Frank’s wounded storytellers press illness memoirs and testimony into service as narrative prostheses that reconstitute selfhood fractured by disease. Ogden’s sensorimotor framework treats the therapeutic dyad itself as a corrective relational apparatus, explicitly foregrounding ‘implicit relational knowing’ as both the wound and the vehicle of repair. Herman’s developmental data implicate the earliest caregiving bond as the constitutive relational structure whose failure produces the dissociative and borderline sequelae that later clinical relationships must remediate. Sacks and Gallagher, approaching the question from neurology and phenomenology of embodiment, document how physical prostheses interact with body-image and phantom sensation, offering an analogue for the relational domain. The central tension in this material concerns whether such supplementary relational structures restore an original capacity or produce a new, structurally dependent configuration — a question the corpus raises but does not resolve.