There was as big a reaction after the revelations about Assad's chemical weapons. Nevertheless, that photograph did strike a singular chord. Which leads us to a larger fact: we don't understand why certain photographs create such an upheaval in one's soul. You look at them and go, "Oh my gosh." And that doesn't happen with television. It's unique to photography. Photographs are unique in that they are a frame abstracted out of reality, out of, in this case, a civil war. A single event can carry so much weight. And that is extraordinary.

Social media's currency is the single photograph. Whereas, every time I look at a photograph, I look at twenty or thirty photographs. I'm looking for a narrative. And that's a different kind of construct. If you're a poet and you put a line from your poem online, "The trees bending over gracefully," or something, you can get a tick. But that has nothing to do with your longer poem.

We don't understand what photography is doing. We don't understand the power of its rhetoric. We don't understand why the Provoke photographers showed Tokyo city as a ghastly and alien city when it was really going through this period of mega-capitalist growth. It's a very, very, very powerful force, the photograph. People ask me why it has such an ability to captivate us. And I just don't know.

In the documentary impulse, two species of 'fact' exist side by side: one is coolly objective and the other is fraught, diverse and emotive; one figurative, the other abstract; one prosaic, the other poetic; one factual, the other romantic.

We create these walls between fact and fiction, but often the difference between the two is as little as that between a real name and a pseudonym. So I'm not sure about those walls - certainly not in the realm of visual arts.

Well, people from the "me" generation use photography to show off what they are doing, to show the world themselves and their friends. Those sort of diarized accounts have always been there. But the phenomena of making those diaries public is new, isn't it?

I think it's terribly important to reach out and understand all the different types of life and the different types of challenges that are present around the world. And I think the more people who can do that the better our planet will probably be.