In 1949, psychoanalyst Jacques Lacan introduced the concept of the 'Mirror Stage,' positing that an infant's recognition of its own reflection creates an illusory sense of a unified self. This recognition fundamentally splits the subject between their reality and the ideal image they perceive. Lacan's theory has had profound implications for psychoanalysis, philosophy, and cultural studies, reshaping the understanding of identity and subjectivity.

Jacques Lacan's formulation of the 'Mirror Stage' in 1949 revolutionized literary theory, particularly in understanding identity and the gaze. This concept deeply influenced confessional poetry and feminist critiques, prompting writers to explore themes of self-perception and the fragmented nature of identity.