In "The Structuralist Activity," of 1960, Roland Barthes defines structure as a simulacrum of the object in which something new occurs: the simulacrum is "intellect added to the object," making something appear which remained invisible, or if one prefers, unintelligible. For Barthes, "Structural man takes the real, decomposes it, then recomposes it."
Poststructuralist thinkers sever the link between the natural object and its imitation.
For them, a simulacrum is a copy without an original.
Thus, the function of the simulacrum is to effect the derealization of the surrounding world of everyday reality. (Jameson) Jameson describes photo-realist art as a simulacrum. It seemed to be about a return of realism after the hegemony of abstraction, but its obects were not "real," but rather images.
For Baudrillard, postmodern reality is hyperreality: a condition in which the real and the imaginary are confused.
"Produced by a code or linguistic form that does not really refer but merely simulates reference, the simulacrum is the image or the reproduction that testifies to the short-circuiting of reference in postmodernism." (Simpson, Time, Technology, and the Conversations of Modernity.), p.138) For Simpson, "The simulacrum is the form that value takes in postmodernism. Simpson distinguishes value from meaning. The latter is inseparable from practice (cf. praxis) whereas the former becomes a subjective matter of will.
Is a computer program a simulacrum?
Is the virtual a state of simulacrum? In Plato, ideas and simulacra exist in some state of virtuality
In her influential " Cyborg Manifesto" Donna Haraway calls microelectronics the technical basis of simulacra. (p. 165)