Three Essays on the Theory of Sexuality

Sigmund Freud’s 1905 work argues that sexuality begins in infancy and develops through changing forms of pleasure, shaping adult desire and psychosexual development.

Infantile sexuality: The idea that bodily pleasure and sexual drives are present from infancy, though not in adult form. The essays make childhood sexuality central to the formation of adult desire.
Oral stage: The proposed early phase of psychosexual development in which pleasure is centered on the mouth. Sucking is one of Freud’s examples of pleasure initially detached from nutrition.
Sigmund Freud: An Austrian neurologist who founded psychoanalysis and developed influential theories of the unconscious. Freud wrote the essays and revised them repeatedly across later editions.
Behaviorism: A psychological approach that explains behavior through observable actions and learning rather than unconscious drives. Its emphasis on learning contrasts with Freud’s account of unconscious sexual development.
Psychosexual development: Freud’s account of how libido develops through successive bodily and psychological stages. The work lays out the developmental framework later called psychosexual development.
Anal stage: The proposed phase in which pleasure and conflict are associated with bowel control and elimination. Freud treats control of bodily functions as a formative source of pleasure and conflict.
Psychoanalysis: A theory and therapeutic practice centered on unconscious mental processes, conflict, and desire. The book is an early foundational work in Freud’s psychoanalytic project.
Attachment theory: A theory of how early caregiver relationships shape emotional bonds and later social development. It offers a different developmental framework, centered on relationships rather than libido.
Libido: In psychoanalytic theory, the psychic energy associated with sexual drives and desire. Freud uses libido to explain how sexual drives change direction and organization.
Phallic stage: The proposed phase in which children’s attention centers on the genitals and related family fantasies. The essays’ discussion of childhood sexual theories anticipates this developmental phase.

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