The imaginary is one of the three orders that structure human existence, the others being the symbolic and the real.
Lacan's concept of the Imaginary first appeared in his 1936 paper "The Mirror Stage".
The imaginary arises from the infant's experience of its specular ego.
In the mirror stage, the child identifies with the specular image, and this inaugurates the series of identifications that will consturct the ego.
The child is literally captivated by a specular other thanks to an identification which is also an alienation.
The imaginary is thus the realm in which self and other merge, and in which identity is grounded in a mere semblance of unity.
The imaginary is not a stage which is overcome or transcended, and is a cosntant presence in the lives of human subjects.
It arises with the mirror stage but extends far into the adult individual's experience of others and of the external world.