In 1981, I think, for the Kunsthalle in Düsseldorf. Before that I designed a mirror room for Kasper König's Westkunst show, but it was never built. All that exists is the design - four mirrors for one room.

Form is all we have to help us cope with fundamentally chaotic facts and assaults. Formulating something is a great start. I trust form, trust my feeling or capacity to find the right form for something. Even if that is only by being well organized. That too is form.

I believe that art has a kind of rightness, as in music, when we hear whether or not a note is false

Now there are no priests or philosophers left, artists are the most important people in the world.

Since there is no such thing as absolute rightness and truth, we always pursue the artificial, leading, human truth. We judge and make a truth that excludes other truths. Art plays a formative part in this manufacture of truth.

Yes, we were amazed when that happened. It was a real joke to us. Konrad Lueg and I did a Happening, and we used the phrase just for the Happening, to have a catchy name for it; and then it immediately got taken up and brought into use. There's no defence against that - and really it's no bad thing.

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.