identity

Identity refers to the set of features, beliefs, memories, and expressions that define an individual or group, distinguishing them from others. It encompasses personal identity—the sense of self and continuity over time—and social identity—the memberships that come from being part of families, communities, ethnicities, nationalities, or professions. Identity also appears in legal and digital contexts, where official documents or data profiles establish a person’s status or access rights.

Personal identity and continuity. Philosophers ask how identity persists through change: memory, consciousness, and bodily continuity play roles. Theories include psychological continuity, which links successive experiences and traits; bodily continuity, based on physical sameness; and narrative identity, where life stories shape the sense of self. Thought experiments such as the Ship of Theseus illustrate challenges to persistence under substitution or replication.

Social and cultural identity. People derive identity from group affiliations—gender, ethnicity, religion, language, nationality, and profession. Social identity theory examines how group membership influences self-concept and relations with others. Cultural identity reflects shared practices, values, and symbols, while intersectionality recognizes that individuals hold multiple, sometimes conflicting, identities across contexts.

Legal and digital identity; privacy and security. Legal identity relies on official records—birth certificates, names, and IDs—that enable rights and responsibilities. Digital identity relies on online accounts, credentials, and data traces, enabling access and authentication but also raising concerns about privacy, surveillance, and identity theft. Because identity is context-dependent, individuals may present different identities in different arenas.