'The question Eilenberger sets out to answer in this ambitious, enthralling book: what use is philosophy in the middle of a war?' The Sunday TimesThe year is 1933. Hannah Arendt escapes Berlin, seeking refuge among the stateless gathering in Paris. Simone de Beauvoir reimagines the dance between consciousness and the world outside in a Rouen café.

Ayn Rand labours in Hollywood exile on the novel she believes destined to reignite the flame of liberty in her adoptive nation. Simone Weil, disenchanted with the revolution's course in Russia, devotes her entire being to the plight of the oppressed. Over the next decade, one of the darkest in Europe's history, these four philosophers will conceive in parallel ideas that would circle the globe in the second half of the century, reshaping it.

The Visionaries follows in its protagonists' footsteps from Leningrad to New York, Spain at civil war to France under occupation, as each is uprooted by totalitarianism's ascendence. It shows them facing the injustices, unfreedom and unfathomable violence of their time as women, refugees, activists, resistance fighters - but above all as thinkers. Wolfram Eilenberger expertly distils the radical philosophies each lived as well as created, showing the two to be part of the same story, all testament to the redemptive power of thought.