"Forget that life is enveloped not just by known unknowns but unknown unknowns, and you will fall like Icarus from the sky".

BBC Radio 3, Monday April 29 - 22.45 and online

In the Essay this week, five contributors - journalists Mark Vernon, Madeleine Bunting, Alastair Campbell; scientist Susan Greenfield, and historian Jennifer Michael Hecht - make The Case for Doubt - the idea that political, religious, and scientific doubt, even self-doubt, though sometimes troubling, is much more useful and valuable than fixed opinions and beliefs.

In this first Essay on doubt in politics, author and broadcaster Mark Vernon argues that a dislike of doubt in politics implies a loss of faith in politics, and that politicians - for their sake as well as ours - should stop cultivating delusions of omnipotent power.