Wolfram Eilenberger’s previous book, the bestselling Time of the Magicians (2020), explored the four Germans – Ernst Cassirer, Walter Benjamin, Martin Heidegger, and Ludwig Wittgenstein – who ‘invented modern thought’. The Visionaries keeps to the formula, this time with women in the lead roles. It is described as a group biography, but Hannah Arendt, Simone de Beauvoir, Ayn Rand, and Simone Weil were very much not a group. Nor is it a biography: there is scant biographical information and no analysis of why they lived as they did. Apart from being born at the same time, writing books, and sharing what Eilenberger calls an ‘honest bafflement that other people live as they do’, the quartet have nothing in common: Arendt was a German Jew escaping the Gestapo; Beauvoir a French intellectual on a mission to enjoy herself; Rand a Russian émigré refashioned as an American neoliberal; and Weil a latter-day Joan of Arc. The closest any of them came to meeting was when Beauvoir, for whom the existence of others was ‘a danger to me’, was introduced to Weil, who had wept at the news of famine in China. It did not go well. The only thing that mattered, Weil announced, was a revolution to feed the world’s starving, to which Beauvoir ‘retorted that the problem was not to make men happy but to find the reason for their existence. She looked me up and down. “It’s easy to see you’ve never been hungry”, she snapped. Our relations ended right there.’

Philosophers attending a conference in the Swiss resort of Davos in 1929 eagerly anticipated a debate between Ernst Cassirer, a celebrated member of the academic establishment and a supporter of progressive liberalism, and Martin Heidegger, whose radical break from tradition had impressed younger philosophers. For those who expected a clash of titans, the result was disappointing. There were no denunciations, no rhetorical bolts of lightning. The true parting of their ways came later, in 1933, when Cassirer, a Jewish supporter of the Weimar Republic, was forced out of his position and into exile, and Heidegger, now a member of the National Socialist Party, told students of Freiburg University to be guided by the Führer.