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.

As humans, we need to question all these notions. What does freedom mean for us? What are our responsibilities? It takes one-250th of a second to take a photograph. So I have the whole of the rest of that second - and of that day - to think.

I was always interested in drawing and painting. I enrolled in college to study painting. But I didn't have any livelihood when I graduated. My mother died very young, and I didn't have any home, so I had to find a way to earn a living. It seemed to me that photography - to the great disappointment, I have to say, of my painting teacher - could offer that. So I went and did a degree in photography, and then after that I could go out and get paid for work. For portraits, things like that.

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.

Newspaper photographs nowadays are highly tautologous. You'll have an article about, say, stopping the war. And the photograph that will be used is literally a poster that reads "Stop The War." Or you'll have a story about a cash crisis in Barcelona, and the only picture you'll see is an ATM in Barcelona. The problem is actually systemic. On the one hand, you'll have a picture of a soda can to "illustrate" an article about the dangers of sugary drinks. On the other hand, anything that's reasonable in documentary photography is snapped up by the art world and we never see it.

Photography for me has been tremendously good, because I'm not a very sociable person. I'm happy reading or sitting in the library or going for walks. So photography has brought me in contact with people and made me understand people in a way that I probably wouldn't have done if I hadn't been a photographer. And so I'm grateful for that, really.

We sort of understand how painkillers work. You take one, and it reduces your headache. We don't understand how photographs work. And that, to me, is an essential problem as a practitioner.