As a matter of fact, it was only through the dealer Fred Jahn that I succeeded in overcoming my reservation about the works on paper and exhibiting them. Added to this, of course, was the fact that after ten years I could see the watercolours in a different light, and in conjunction with pictures painted afterwards, they had at least become more comprehensible to me.

It was not possible for us to produce the same optimism and the same kind of humour or irony. Actually, it was not irony. Lichtenstein is not ironic but he does have a special kind of humour. That's how I could describe it: humour and optimism. For Polke and me, everything was more fragmented. But how it was broken up is hard to describe.

Perhaps the Doors, Curtains, Surface Pictures, Panes of Glass, etc. are metaphors of despair, prompted by the dilemma that our sense of sight causes us to apprehend things, but at the same time restricts and partly precludes our apprehension of reality.

I have no motif, only motivation. I believe that motivation is the real thing, the natural thing, and that the motif is old-fashioned, even reactionary (as stupid as the question about the meaning of life)

All photographs are far more important than any painting.

Almost every work of art is an analogy. When I make a representation of something, this too is an analogy to what exists; I make an effort to get a grip on the thing by depicting it. I prefer to steer clear of anything aesthetic, so as not to set obstacles in my own way and not to have the problem of people saying: 'Ah, yes, that's how he sees the world, that's his interpretation.'

Abstract pictures are fictive models, because they make visible a reality that we can neither see nor describe, but whose existence we can postulate.