I think, oddly, that the world of the amateur is quite self-contained, and it depends on "likes" from other amateurs to perpetuate itself. Of course an awful lot of my colleagues are involved with Instagram - they get likes and dislikes, maybe just likes, I don't know - but I think that it's far less self-contained, the world I work in. It goes off in different directions, and is dependent on responses different from a tick or a like or whatever.

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.

There was a time, right up until the end of the Second World War and beyond, when white people in Europe thought that they basically owned the world and that everybody else was a sort of servant, or a curiosity, or whatever. And that informed 99 percent of the photographic practice that was done. Without being able to address that, I felt I would have failed in my attempt to explain what the urge to document is.

It's certainly important to include text beside documentary photographs. Furthermore, it's important to include text in a way that's useful and accessible.

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.

There's an awful lot of work being done that no one ever sees, or that is only seen in the gallery world. I feel that the public are losing touch with the great stuff that's being done in photography.

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.