As a young man I worked very methodically in the museums; I went there really to understand things, to get things, so to speak, into my system. I was always interested in how the whole of a painting is made and how the parts are integrated. I remember there were times when I only looked at how the different artists treated the ears, the nose, the hair, how they made the neck come out of the body. By doing that you get a kind of knowledge of how to do it, or how not to do it.
Also when I was young, I copied many drawings of Michelangelo, Leonardo da Vinci and Raphael, all from reproductions. I remember certain paintings of Titian for instance. I looked a hundred times at them and so I derived a very clear vision of how they were done. After experiencing the painting of many centuries like this, little by little, a notion of what unifies them begins to grow. You see each painting as a member of a great family. And the single member becomes less important than, let us say, the family resemblance. I always looked for this family resemblance more than for the particular expression of such and such an artist. In other words, I forced myself to look at what unified all of these works. This, I believe, gave me an understanding of the past, which few students seem to have these days.
Also, when I was very young, I was taken with tropical plants and animals and I spent many afternoons in the zoological gardens in Nuremberg. I got a lot out of that, a sense of weight, movement, form, everything one looks for in nature. I never drew a single animal of plant, but I looked at them very closely. This helped me later for my study in the museums, because I did it the same way. I compared animal with animal and I think if I had not looked so closely and methodically at living creatures, I probably would have been less attentive to works of art.