Hello I'm Krestey Young and this is a podcast from the Desert Island Discs archive.

For rights reasons, we've had to shorten the music.

The program was originally broadcast in 1996 and the presenter was Sue Lolly. My cost away this week is a scientist. He was born in South Africa where his childhood was unhappy and after university

there he came to England. Here he rapidly established himself as a leading scientific

thinker. His field is embryology, the study of cells and how they develop,

but his influence stems from his passionate advocacy of the value of science as a whole.

Despite a recent attack of clinical depression, he remains convinced that science provides the only rational foundation for man's beliefs.

We must live with uncertainty, he argues, rather than sustain ourselves with improbable beliefs.

His job is being the professor of biology as applied to medicine at University College London,

but his public role lies in his position as Chairman of the Committee on Public Understanding of Science.

He is Louis Walpert.

You have, however, currently Professor Walpert become Professor of Depression, haven't you?

You've gone very public about this illness you had.

Why did you choose to do that?

It was the only time I never been depressed,

and it was so unspeakably awful in the first instance.

And then I realized that people were slightly embarrassed

about me having a depression

and that other people who were depressed

was somewhat ashamed of it. It has a stigma

being depressed and I felt it was very important for this to be removed.

But what kind of depression was yours? Was it just simply a very long low period?

...