Simulacra and Simulation by Jean Baudrillard

Of all the prostheses that mark the history of the body, the double is doubtless the oldest. But the double is precisely not a prosthesis: it is an imaginary figure, which, just like the soul, the shadow, the mirror image, haunts the subject like his other, which makes it so that the subject is simultaneously itself and never resembles itself again, which haunts the subject like a subtle and always averted death. This is not always the case, however: when the double materializes, when it becomes visible, it signifies imminent death.

In other words, the imaginary power and wealth of the double - the one in which the strangeness and at the same time the intimacy of the subject to itself are played out (heimlich/ unheimlich) - rests on its immateriality, on the fact that it is and remains a phantasm. Everyone can dream, and must have dreamed his whole life, of a perfect duplication or multiplication of his being, but such copies only have the power of dreams, and are destroyed when one attempts to force the dream into the real. The same is true of the (primal) scene of seduction: it only functions when it is phantasmed, reremembered, never real. It belonged to our era to wish to exorcise this phantasm like the others, that is to say to want to realize, materialize it in flesh and bone and, in a completely contrary way, to change the game of the double from a subtle exchange of death with the Other into the eternity of the Same.