"There is a famous man called Galton who takes photographs of mad people and then lays the images one on top of the other. He is trying to show that all murderers have the same shaped head, or that if you have a long jaw you are likely to be melancholic."
"And that is not what you do?"
"No. I do just the opposite. I use them to make patients look like less of a type and more of an individual. When I see them in their wards, I see a sort of undifferentiated mass. But when I take a picture, I see each man and woman. And each one is in fact a human with a story. In some ways the insanity is the least important thing about them. In a photograph they are still complete, so one is not tempted to see them so much as something broken."