To believe, one must have lost God. To paint, one must have lost art.

Theory has nothing to do with a work of art. Pictures which are interpretable, and which contain a meaning, are bad pictures. A picture presents itself as the Unmanageable, the Illogical, the Meaningless. It demonstrates the endless multiplicity of aspects; it takes away our certainty, because it deprives a thing of its meaning and its name. It shows us the thing in all the manifold significance and infinite variety that preclude the emergence of any single meaning and view.

I didn't actually know what the protesters in the West really wanted. It was fantastic here, so much freedom, and that was what they were calling musty, middle-class, and fascistic, a bleak period. Bleak was what the GDR was, and it alone had adopted, almost unchanged, Nazi Germany's methods of intimidation and ideas about propaganda and the use of force.

The truth... When they have a similar structure to and are organized in as truthful a way as nature. When I look out of the window, then truth for me is the way nature shows itself in its various tones, colours and proportions. That's a truth and has its own correctness. This little slice of nature, and in fact any given piece of nature, represents to me an ongoing challenge, and is a model for my paintings.

Photography has almost no reality; it is almost a hundred per cent picture. And painting always has reality: you can touch the paint; it has presence; but it always yields a picture - no matter whether good or bad. That's all the theory. It's no good. I once took some small photographs and then smeared them with paint. That partly resolved the problem, and it's really good - better than anything I could ever say on the subject.

To me, grey is the welcome and only possible equivalent for indifference, noncommitment, absence of opinion, absence of shape. But grey, like formlessness and the rest, can be real only as an idea, and so all I can do is create a colour nuance that means grey but is not it. The painting is then a mixture of grey as a fiction and grey as a visible, designated area of colour.

It is a danger to wait around for an idea to occur to you. You have to find the idea.