Like our attitude to love, truth and goodness, we seem to be confident about knowing what beauty is - certain, even dogmatic - until we think hard about the idea, whereupon all confidence flies away.

What is the most interesting thing to people? Other people.

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.

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.

It's a mark of any icon that it should be open to iconoclasm.

Science is a victim of its own reductive metaphors: 'Big Bang,' 'selfish gene' and so on. Richard Dawkins' selfish gene fitted with the Thatcherite politics of the time. It should actually be the 'altruistic gene,' but he'd never have sold as many books with a title like that.

But I do believe architecture, and all art, should be content-driven. It should have something to say beyond the sensational.