But more unnerving was Sontag’s proclamation of the camera as a weapon. “To photograph people is to violate them,” she wrote. The more images of violence we see—of war; of victims of hunger or famine; or other injustices—the more immune to them we become.

In recent years, the Black Lives Matter movement has decried the circulation of pictures showing violence against the black body. This issue was at the root of the 2017 protests at the Whitney Museum , which challenged a white painter’s depiction of a photograph of the mutilated Emmett Till in his coffin. “Photographs shock insofar as they show something novel,” Sontag wrote four decades before the brouhaha. “Unfortunately, the ante keeps getting raised—partly through the very proliferation of such images of horror.”

More than any other 20th-century critic, Sontag gave readers a reason to care about photography. Whether at a conscious or subconscious level, the images that bombard us daily affect how we finetune our sense of morality and our perceptions of the world. In 2019, her writings still incite more mindful looking, picture-taking, and consideration of the way we experience so much of modern life: through screens and lenses.