It is not an individual act, architecture. You have to consider your client. Only out of that can you produce great architecture. You cannot work in the abstract

Life is architecture and architecture is the mirror of life.

For Kips Bay, I had a wonderful client, William Zeckendorf, who was willing to gamble with me on using concrete and not brick for a high-rise apartment building. That was very innovative at the time.

Luxembourg was and still is today a crossroads, the place where Germany meets the rest of Europe. The country lost part of its territory to Belgium in the 1800s, and during World Wars I and II the German military overran it. Very few people have visited Luxembourg - when I went there and looked at it, I said, my God, it's built on a rock. And within the rock they had a castle, and within the city there's a network of tunnels so the residents could move around and defend themselves. That was of great interest to me.

I believe that architecture is a pragmatic art. To become art it must be built on a foundation of necessity.

When I got the opportunity to do the new wing [the Schauhaus] for the German Historical Museum, for instance, I didn't see it as an opportunity for my own ego, to do something so exciting that every architectural publication would want to put it on the cover. I accepted it because I knew it was going to be a very difficult project, and I wasn't sure I could do something exciting there.

François Mitterrand was a student of architecture, he had done a lot of research before he called me. He said, "You did something special at the National Gallery of Art in Washington - you brought the new and the old together." But John Russell Pope finished the West Building in 1941, so when the East Building opened it was only about 40 years old. But the Louvre is 800 years old! A much bigger design challenge.