from "On Photography" by Susan Sontag

"In photography's early decades, photographs were expected to be idealized images. This is still the aim of most amateur photographers, for whom a beautiful photograph is a photograph of something beautiful, like a woman, a sunset. In 1915 Edward Steichen photographed a milk bottle on a tenement fire escape, an early example of a quite different idea of the beautiful photograph. And since the 1920s, ambitious professionals, those whose work gets into museums, have steadily drifted away from lyrical subjects, conscientiously exploring plain, tawdry, or even vapid material. In recent decades, photography has succeeded in somewhat revising, for everybody, the definitions of what is beautiful and ugly along the lines that Whitman had proposed. If (in Whitman's words) "each precise object or condition or combination or process exhibits a beauty," it becomes superficial to single out some things as beautiful and others as not. If "all that a person does or thinks is of consequence," it becomes arbitrary to treat some moments in life as important and most as trivial."

– Susan Sontag, 1977