In The Visionaries Wolfram Eilenberger opens doors into the lives of four great thinkers in a dark time, each born in the first decade of the 20th century: Hannah Arendt, Simone de Beauvoir, Ayn Rand and Simone Weil. He begins with glimpses of them in 1943, before tracing their struggles and successes from 1933 up to that moment. What unites these women and their work? The book’s original German title, Feuer der Freiheit (‘Fire of Freedom’), provides a clue that the English The Visionaries does not. In 1933, Hitler came to power, fire broke out in the Reichstag and Germany became a dictatorship. In 1943, while war and totalitarianism were at their pinnacle in Europe, across the Atlantic American libertarianism saw its literary dawn. In the interim, whether in Germany, France, England, the Soviet Union or the United States, the questions of how to live and what freedoms were worth fighting for were among these women’s most faithful companions. Each went on to envisage free and open societies in ways that shaped the 20th century and continue to shape the 21st.

Eilenberger’s episodic narrative permits him to portray the evolution of these questions in the thought and actions of the four women over time. For some of them, life was an existential experiment and liveability the litmus test of a philosophy. For the three who were Jewish (Arendt, Rand and Weil), life itself could not be taken for granted and attempting to secure it meant displacements and uncertainty about the security of those they loved. For Beauvoir, by contrast, political apathy was possible and, as she later acknowledged with remorse, actual. Although their voices were discordant, by 1943 each woman had become ‘a philosopher with a real political mission’.

Where the Simones are concerned, Eilenberger ably avoids cliché: there is no Beauvoir Notre Dame de Sartre or wholly otherworldly St Weil in these pages. Indeed, we learn that Weil rinsed her sinuses with cocaine. Both travelled to Berlin during the first two years of Nazi rule, but only