Self

Self refers to the sense of being a distinct, persisting individual, the subject of experiences and actions. It includes an immediate sense of agency and ownership, as well as longer-standing constructs such as self-concept, self-esteem, and self-identity. The term is used across philosophy, psychology, cognitive science, and neuroscience, with varying emphases on phenomenology, cognitive representation, and social context.

In philosophy, the self has been debated for centuries. Descartes proposed a thinking self (cogito) as the essential basis of knowing. Kant argued for the transcendental unity of apperception that underlies experience. Hume offered a bundle theory, suggesting the self is a collection of perceptions without a fixed core. Non-Western traditions, such as Buddhism, describe anatman—the absence of a permanent self. Theories of personal identity examine what makes someone the same person over time, balancing psychological continuity (memories, character) against physical continuity.

In psychology and neuroscience, the self comprises self-schemas, self-esteem, and the sense of agency. Self-recognition in mirrors is used as an index of self-awareness in children and some animals. Neuroscientific work links the sense of self to networks in the brain, including the default mode network and systems for agency attribution and body ownership.

Developmentally, self-awareness emerges in infancy with cues like mirror recognition and joint attention, and expands through language and social experience. The self also arises in social identity, with roles, group memberships, and cultural narratives shaping how individuals see themselves.

Dysfunctions include depersonalization, derealization, and dissociative identity disorder, which can alter or fragment self-experience. The concept remains central to understanding consciousness, autonomy, and human behavior.