On Photography is an exploration of industrial consumerist society and photography’s place in this socioeconomic structure. Sontag conducts this exploration through photography’s relationship with the idea of the spectacle (see: Index of Terms). Sontag theorizes that photography is one of the most easily accessible forms of surreal spectacle because of the ability to endlessly replicate photographs and film. Spectacle is central to the functioning of a hyper-consumerist society. In Sontag’s logic, photography is a central pillar of modern, hyper-consumerist society because of its ability to endlessly produce spectacles for consumption. Photography is essential to consumerism.

Sontag’s exploration of photography’s relationship to consumerism introduces her work in the first essay, “In Plato’s Cave,” and ends the collection in her concluding essay, “The Image-World.” This theme’s presence at the beginning and end of On Photography positions it as Sontag’s largest theoretical preoccupation. She writes:

Movies and television programs light up walls, flicker, and go out; but with still photography the image is also an object, lightweight, cheap to produce, easy to carry about, accumulate, store. […] [Writing is a] now notorious first fall into alienation […] needed to build modern, inorganic societies. But print seems a less treacherous form of leaching out the world […] than photographic images […] (1-2).