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.

A placebo is a phony cure that works. This is very hard for the medical profession to get their teeth around because they hate placebos, but scientifically, placebos work in about 30% of cases that are psychogenic diseases.

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.

Cant you see, we are in a dialogue with the universe?

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.

I was already writing about the idea of a 'multiverse' in the 1970s, though I might have called it the 'pluriverse.' How was I to know it would turn out to be the standard model? Actually, I consider myself an enlightenment fossil.

In 1979, postmodernism lost its understanding of the meaning of ornament. It degenerated into kitsch applique.

You have to believe in a placebo or it wont work, but if it works, its obviously working in some indirect way, through feedback in the immune system, let us say, or in the willpower of the patient to take a more strenuous exercise in their own therapy.

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

The singular point of beautiful objects, and people, is that they are experienced not as parts, or ratios between cheekbones and chin, but as wholes. The experience of beauty is a perception, but it is one that mixes up various other sensations and makes them converge in a particular way.

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

I'd been to Stourhead and was inspired by the perfect parity between architecture and art in fact, the architecture is the art. I wrote a piece called 'Not Sculpture Park,' because most of these things become car parks for bought-in sculpture. The artists should be working with the site, not just plonking pieces down.

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

I think any cancer patient, if you dig not too deeply, they want to live.

What is a garden if not a miniaturization and celebration, of the place we are in, the universe?

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