I've been a lucky man. I've only faced one real tragedy: the death of my wife, Maggie, from cancer in 1995.

You know, Darwin said through natural selection things go gradually, and he was talking about pigeon's evolution or horses evolving, getting faster. But in fact if you look at evolution on a bigger scale, cosmic evolution and you look at culture evolution you see it jumps, it goes through phase changes, and that's very exciting.

The cell is a city of production centres, each part working away like mad, and it's co-ordinated. Six trillion cells in a body - you can't help but be moved.

A sign to me is a one-liner, a symbol is very complex and my house is a series of symbols.

If you look at Gothic detailing right down to the bottom of a column or the capital of a column, it's a small version of the whole building; that's why, like dating the backbones of a dinosaur, a good historian can look at a detail of a Gothic building and tell you exactly what the rest of the building was, and infer the whole from the parts.

If you look at any leaf on any tree branch, it's similar to but not exactly a repetition of the previous branch. So the new science of complexity or showing how an architecture can be produced just as quickly, cheaply and efficiently by using computer production methods to get the slight variation, the self-similarity.

The rule seems to be that there are no absolutes, that what is rare is prized. Thus, in times of relative affluence, thin models become dominant.