Michel de M'Uzan describes a way to think about identity in which two distinct sources of our sense of identity must be considered. His innovation is the concept of the vital-identital, which he suggests is equally foundational with the sense of identity derived from the early human environment. The term endogenous identity is used to unify under one heading the ideas that de M'Uzan employs to build his concept of vital-identital. The author summarizes de M'Uzan's earlier work, elaborates on his more recent ideas, and illustrates the use of de M'Uzan's ideas with a cultural and a clinical example.