“In Plato’s Cave” compares photography to the shadows on the wall in Plato’s famous allegory. While Plato was concerned about the effects of artisanal images on people’s minds, Sontag argues that photography has introduced a nightmarish new relationship to images that Plato couldn’t have predicted—a “new visual code” (1) that reorients all of society in ways that were impossible before the invention of photography. Sontag believes that photographs give people a false sense of knowledge and power over a situation because of their ability to capture slices of time and immortalize them. This sense of knowledge and power over an event or subject makes photography a form of appropriation and social control. Photographs make reality into a series of discrete collectible instances instead of one continuous flow of events.

Sontag looks to famous photographers and organizations to illustrate how aggressive and invasive cameras are. Her two primary examples are Diane Arbus and the Farm Security Administration (FSA). The FSA sought to photograph poverty without bias. Sontag points out that even the FSA took dozens of shots before discerning which photo of their impoverished subjects best fit the bill. Arbus’s photography exemplifies the voyeuristic tourism that Sontag believes is inherent in photography.