Mistakes often provide the best lessons in life, so why are they so undervalued? Michael Blastland explores our attitude to failure and the impact it has on politics. We may accept, in our personal lives, that 'to err is human'. But, when it comes to politicians, we enjoy pouring scorn on those who make mistakes: we relish the cock-up, the blunder and the humiliating U-turn. But what effect does this bloodthirsty approach have on policy-making? Michael talks to former cabinet minister Estelle Morris about her experience of dealing with mistakes in government. We also hear from former civil servant Paul Johnson and from David Halpern - a former prime-ministerial advisor who helped create The Institute for Government. Michael goes in search of inspiration from two professions which, far from seeking to bury mistakes, see them as opportunities to learn. He speaks to surgeon and writer Atul Gawande and he visits RAF Cranwell, where mistakes made by airman are seen as 'clues'. He also talks to philosopher Susan Wolf about blame and 'moral luck' and he interviews the editor of The Spectator magazine, Fraser Nelson.