What is the self? This age-old question is one that, surprisingly, receives little attention even among researchers who study it. In our view, addressing this important question begins with acknowledging that the self is composed of multiple, context-dependent self-aspects represented in an interrelated memory network. These self-aspects develop in the service of pursuing important self-relevant goals (e.g., reproduction, achievement, belongingness) and re ect one's important qualities exhibited in these domains. Because context activates a goal-relevant self-aspect, discrete subregions of self-knowledge are activated at any given time, which limits the impact of core personality attributes and shapes the experience of current affect. This approach has broader implications for explaining how the self can be both stable yet variable, for the conditions under which self-concepts develop and change, for distinguishing between the self as the known and the knower, and for goal pursuit and self-regulatory activities.