In the field of psychopathology, the approach to “narcissistic and identity-related suffering” invites us to undertake a rereading of the modalities of structuration of subjectivity in the course of development. In this article, the author proposes elements of a modelization of the construction of identity based on the paradigm of the double. Approached from the angle of paradox, identity is thought of as a process in the service of “becoming a subject” which is based, essentially, on the role of the object and its reflexive function. Drawing on the concept of “transitional double”, this perspective leads the author to describe the stages of the construction of the foundations of subjective identity which underlie the creation of an internal psychic mirror, the locus of the relationship to oneself. These considerations help us to gain a better understanding of the logics of narcissistic and identity-related pathologies, which are characterised in particular by a failure of reflexive capacities, reflecting the uncertainties of the dual relational dynamic in the course of early development.