What is identity? What is a self? How has selfhood changed over time?
Those are the questions that Charles Taylor, a philosopher with a historical method, sets out to answer in Sources of the Self: The Making of the Modern Identity (Harvard University Press, 1989). His book is an investigation of how the modern sense of what it means to be a person came into being through the influences of philosophers and popular thought. To that end, he first lays a philosophical foundation, then offers a history of selfhood that is somewhere between straightfoward intellectual history and a history of mentalités.
Taylor’s basic argument is that the concept of the self in linked to morality. Morality means not simply a set of claims about what one ought to do or not do to be moral; rather, it means what one ought to be or not be. Morality is related to the self by what Taylor calls a framework. How one thinks about oneself depends (1) on what one considers to be the Good and (2) how one relates to that Good. If this all sounds very philosophical, it is. But the insight is rather simple, though profound: you can only think of yourself as you think of yourself in relation to what is most important.
