Wiktionary
n. A concept concerning the structure of human subjectivity and the imaginary order in the psychoanalysis theory of http://en.wikipedia.org/wiki/Jacques_Lacan.
Wikipedia
The mirror stage is a concept in the psychoanalytic theory of Jacques Lacan. The mirror stage is based on the belief that infants recognize themselves in a mirror (literal) or other symbolic contraption which induces apperception (the turning of oneself into an object that can be viewed by the child from outside themselves) from the age of about six months.
Initially, Lacan proposed that the mirror stage was part of an infant's development from 6 to 18 months, as outlined at the Fourteenth International Psychoanalytical Congress at Marienbad in 1936. By the early 1950s, Lacan's concept of the mirror stage had evolved: he no longer considered the mirror stage as a moment in the life of the infant, but as representing a permanent structure of subjectivity, or as the paradigm of " Imaginary order". This evolution in Lacan's thinking becomes clear in his later essay titled "The Subversion of the Subject and the Dialectic of Desire."