Acclaimed British playwright and novelist Michael Frayn's lifelong interest in philosophy, which underpins much of his fiction and plays, has culminated in The Human Touch, a bold excursion into the role of human imagination.

Your friend and former tutor at Cambridge, philosopher Jonathan Bennett, calls your central argument "anthropocentrism run amok." How do you respond?

We all accept, I'm sure, that the universe is there and is what it is whether we're here or not. Human beings are an extremely peripheral phenomenon, both in space and time. What I'm trying to see, at the same time, is the other side of the coin. Unless we are here to talk about the world and measure it, make comparisons between this thing and that thing, then it's very difficult to see what form or character the universe could be said to have.

The book rigorously undermines common sense certainties as well as the "rules" and "laws" we regard as governing the universe and our sense of self, and demonstrates that indeterminacy and contingency are everywhere. Is that grounds for despair?

I don't find it a criticism of human beings that we only have incomplete and inexact knowledge, that our contact with the world is affected by uncertainty. That just is the nature of things. In spite of this, the human race has found out a staggering amount about the universe. What began as just the necessary mastering of our immediate environment has extended out to the very furthest limits of the observable universe, and back to the beginnings and to the end of imaginable time. It is absolutely astonishing. So I'm not in any way expressing any sense of despair about human achievement. Quite the contrary.

Amateur status vis-à-vis science, philosophy, psychology or linguistics clearly doesn't distress or deter you.

As I make clear in the book, I'm not a philosopher. I'm not a scientist. I am a layman trying to look at these subjects. I do think that, although one's a fool to rush in where angels fear to tread, one's a bigger fool if one doesn't make some attempt to understand what's going on in philosophy and science, particularly in the case of science. Scientific thinking is the dominant mode of thinking in our time. It has transformed our world. It seems willful and stupid, to me, to refuse to try and have some understanding of that, even if one is not a scientist.