This is a podcast from the archives of the BBC Reith Lectures.

This lecture in the series, Innocence and Design, given by David Henderson, was originally broadcast in 1985.

John Maynard Keynes' great work, the general theory of employment, interest and money,

which was published almost exactly 50 years ago, ends with a justly famous tribute to the influence of ideas on events.

The ideas of economists and political philosophers, Keynes wrote,

both when they're right and when they're wrong,

are more powerful than is commonly understood.

Indeed, the world is ruled by little else,

practical men who believes themselves to be quite exempt from any intellectual influences are usually the slaves of some defunct

economist. I'm sure that the power of vested interests is vastly exaggerated compared with the

gradual encroachment of ideas. Its ideas, Keynes wrote, not vested interests, which are dangerous for good or evil.

Not surprisingly, this passage has been quoted many times and his thesis much debated

by economists and economic historians down the years.

I can still remember the excitement and the sense of conviction

which I felt on first reading it as a student in Oxford just over 40 years ago.

Keynes's words cast for me a new light on the world and on the subject I'd begun to try to master.

My own views on this have evolved.

They've been shaped not just by reading the works of scholars, but also, and in fact largely,

by personal experience and observation.

The experience has been of working as a professional economist in a number of different roles and countries.

I can't claim to have greatly influenced the course of events,

and so far as I know, no practical man has ever shown signs of becoming my intellectual slave.

...