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.

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?

Reading is always a way of forming a bond with other people. I'm not very good at socializing - I quite like spending time alone - so reading is a way of engaging quite deeply with the way other people think. Quite often when you meet other people socially you don't get to have a conversation of any depth. You end up talking about how well or how badly someone is doing at school or something of that sort. Questions like, "What we are," "Who we are," "Where are we going," you get those from literature and from people that spend some time thinking.

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.

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.

Photography was increasingly being seen as something outside the art world. As a sort of illustration. They just fired the director of photography at the Sunday Times Magazine - that's where everyone went with their photo essays in the '60s, '70s, and '80s. It was the place to get published. It is an issue. And I feel it. There's no budget. The budget-holders are very often people who've been to the professional colleges where art is not taught. So art as a part of education is something that's missing - since Thatcher's day, anyway.

In the same way, photography, for me, has fragmented. You do have people doing bodies of work - often with found photographs - that are quite hard to understand unless you got a very sophisticated visual history behind you. But there are different camps.