A photograph of a group of suffering people: We look at them, and from the sadness of their expressions and gestures, we know something awful has happened. But finding out exact details, through the photograph alone, is more difficult. Who these sufferers are, why they suffer, who or what caused the suffering and what ought to be done about it: These are entirely more complex questions, questions hard to answer only by looking at the photograph.

The accounts journalists typically give of their motivations, particularly in photographing violence, aren’t always convincing. Why go off to wars or conflict zones at great personal risk to take pictures of people whose lives are in terrifying states of disarray? The answer is often tautological: The images are physically dangerous and psychologically costly to make, and therefore they must be the right images.

Susan Sontag, probably the most influential writer on the intersection of violence and photography, didn’t buy this argument. With forensic prose, she cut through complacent apologias for war photography and set photojournalistic images of violence squarely in the context of viewers’ voyeurism. This was the argument advanced in her 1977 essay collection, “On Photography.” Sontag believed that a certain passivity was inescapable in spectatorship, and that any image of violence would be tainted by this passive distance. “Through the camera people become customers or tourists of reality,” she wrote. Looking at those images, she seemed to suggest, was both self-absorbed and self-absolving.

She revisited the subject near the end of her life, with more complexity and focus. In “Regarding the Pain of Others” (2003), she still viewed photojournalists with skepticism (she dubbed them “star witnesses” and “specialized tourists”), and remained averse to the kind of prurient gaze that images of torment can foster. But she amended some of her earlier positions. She previously argued that photographs, despite their capacity to generate sympathy, could quickly shrivel it through overexposure. She became less sure about that. She also queried the idea, implicit in her earlier arguments and explicit in the work of theorists like Guy Debord and Jean Baudrillard, that the abundance and distribution of images made reality itself little more than a spectacle:

It suggests, perversely, unseriously, that there is no real suffering in the world. But it is absurd to identify the world with those zones in the well-off countries where people have the dubious privilege of being spectators, or of declining to be spectators, of other people’s pain, just as it is absurd to generalize about the ability to respond to the sufferings of others on the basis of the mind-set of those consumers of news who know nothing at first hand about war and massive injustice and terror.

Sontag wondered, near the end of “Regarding the Pain of Others,” whether “one has no right to experience the suffering of others at a distance, denuded of its raw power,” and she came to the conclusion that sometimes a bit of distance can be good. “There’s nothing wrong with standing back and thinking,” she wrote. (Even more than the incisiveness of her judgments, Sontag’s willingness to rethink her views is what endears her to me.) The challenges of viewership have only intensified in the 21st century. Images of violence have both proliferated and mutated, demanding new forms of image literacy. Some recent scholars of photography have argued with some of Sontag’s assertions in “On Photography.” One of those scholars, Ariella Azoulay, has questioned the claim of voyeurism. Azoulay reads images of conflict or atrocity as constituting a more interwoven set of actors, displacing the question from one of voyeurism, and even of empathy, to one of participatory citizenship. We are all in this together, Azoulay seems to be saying (and I don’t think the Sontag of “Regarding the Pain of Others” would disagree). In making such an argument, Azoulay attends to a different tradition in photography writing, one connected to an assertion made in 1857 by Lady Elizabeth Eastlake in The London Quarterly Review: “For it is one of the pleasant characteristics of this pursuit that it unites men of the most diverse lives, habits and stations, so that whoever enters its ranks finds himself in a kind of republic, where it needs apparently but to be a photographer to be a brother.”