Abstract
Theory is a resource for informing one’s practice. The concepts that are highly useful in understanding how a sense of self emerges over the lifespan are drawn from attachment, self psychological and object relations theories. These theories focus primarily on early development. The chapter also attends to the development in later childhood and adolescence and then introduces the emergence of the self in the adulthood. Beginning in this chapter, vignettes from psychotherapy with clients are used to tie concepts to practice.