“But she is mad!” said General de Gaulle. It was the autumn of 1942 and the leader of the Free French movement in London had just received a proposal from a fearfully weak and emaciated woman, practically blind without her glasses, to head a special mission of French nurses to provide first aid at the front. Simone Weil hoped to become, as Wolfram Eilenberger puts it, “a kind of female anti-SS in the spirit of the Maid of Orléans”. The 33-year-old Jewish philosopher wrote: “The challenge would be all the more conspicuous because the services would be performed by women...