The Times hailed Richard Burdon Haldane as 'one of the most powerful ... intellects' British statesmanship had ever seen. His brother John, a great physiologist, invented the first gas masks used in World War One. Their sister Elizabeth was among the first women to become a senior public servant. Their mother Mary, friend and advisor to top politicians and churchmen, nurtured these exceptional minds. Mary's grandchildren swapped her traditional roots for radical socialism, but continued the brilliant family legacy. Naomi Mitchison was a doyenne of Scottish literature; one Nobel prizewinner called her brother, the geneticist J.B.S. Haldane, 'the cleverest man I ever knew'. Like the Darwins and Keyneses, this clan of thinkers lived in rapidly changing times, and helped to remake the world around them. Drawing on extensive family interviews and previously unseen private papers, Serious Minds details scandal, tragedy and achievement within a dynasty that shaped modern Britain-from the welfare state, education system and military, to our understanding of energy, the human body, and the origins of life itself.