the very question of whether photography is or is not an art is essentially a misleading one. Although photography generates works that can be called art—it requires subjectivity, it can lie, it gives aesthetic pleasure—photography is not, to begin with, an art form at all. Like language, it is a medium in which works of art (among other things) are made. Out of language, one can make scientific discourse, bureaucratic memoranda, love letters, grocery lists, and Balzac’s Paris. Out of photography, one can make passport pictures, weather photographs, pornographic pictures, X-rays, wedding pictures, and Atget’s Paris. Photography is not an art like, say, painting and poetry. Although the activities of some photographers conform to the traditional notion of a fine art, the activity of exceptionally talented individuals producing discrete objects that have value in themselves, from the beginning photography has also lent itself to that notion of art which says that art is obsolete. The power of photography—and its centrality in present aesthetic concerns—is that it confirms both ideas of art. But the way in which photography renders art obsolete is, in the long run, stronger.
— Susan Sontag, On Photography, 1977