[Sontag] attributes her essays [in On Photography] to "my obsession with photography" and expresses herself often in the language of disease. She particularly favors "addiction" and "pollution"—"Industrial societies turn their citizens into image-junkies; it is the most irresistible form of mental pollution"—and "compulsive consumption"—"We consume images at an ever faster rate and … images consume reality." Evidently, her intention is to tell what she has learned from her own forced closeness.

In choosing to deal with what William Gass aptly calls "the act of photography at large," Sontag associates herself with a group of writers on photography that includes Hawthorne, Baudelaire, Oliver Wendell Holmes, Moholy-Nagy, James Agee, Richard Rudisill, and, of course, Walter Benjamin. A major difficulty in dealing with the subject defined at large, which can only increase as consciousness of the number and kinds of photography increases, is the tendency to look at photography...