CONCEPT
Index (Semiotics)
The sign that bears a physical, causal connection to its referent—footprint to foot, photograph to photographed subject—whose authority AI-generated images destroy by producing icons that simulate indexical status without possessing it.
The
index is one of three fundamental sign types in
Charles Sanders Peirce's semiotic taxonomy. An icon resembles its referent (a portrait looks like its subject); a symbol refers by convention (the word "dog" refers to canines by linguistic agreement); an index bears a physical, existential connection to what it signifies. A footprint is an index of the foot that made it, smoke is an index of fire, the weathervane is an index of wind direction. Photography's cultural authority—its truth-claim, its evidentiary status—derives from its indexical character: light from the subject struck the photosensitive surface and caused a chemical transformation. The photograph certifies presence. Krauss's analysis of photography in
The Optical Unconscious and subsequent work identified this indexical connection as the medium's defining property, distinguishing it from painting and grounding its unique relationship to reality. AI-generated images sever the indexical connection absolutely—producing icons (images that resemble photographs) that the viewer's perceptual apparatus, trained on photographic conventions, reads as indexes. The gap
between the surface claim