In spring 1929, a group of distinguished scholars convened at the Grand Hôtel Belvédère in the Swiss ski resort of Davos, a place that had already acquired literary fame through Thomas Mann’s Magic Mountain, for a grand philosophy congress. At the meeting, two of the most influential thinkers of the time, Martin Heidegger and Ernst Cassirer, engaged in a philosophical disputation that became legendary. Cassirer, the mild-mannered professor from Hamburg who embodied a cultivated, cosmopolitan, liberal bourgeoisie, represented the philosophical establishment. The significantly younger newcomer, Martin Heidegger, dark haired and tanned from his days on the pistes, was determined to rock this establishment. It was a conflict of opposing personalities and philosophies. Whereas Cassirer, a world-leading authority on Kant, then at the zenith of his career, stood for the enlightenment ideals of human reason, tolerance and civilizational progress, Heidegger, who two years earlier had published his celebrated existentialist magnum opus Being and Time, represented national parochialism, romantic mysticism and an anti-liberal vision of modernity. Their debate on the nature of the human condition in the hotel’s grand hall, attended by a large audience that included Rudolf Carnap, Emmanuel Levinas and Norbert Elias, highlighted these two diametrically opposing worldviews. It was a mirror of the interwar zeitgeist.

The encounter at Davos forms the framework of Wolfram Eilenberger’s magnificent Time of the Magicians, which traces the paths of four towering German-speaking thinkers who revolutionized philosophy, over the decade between the Great War and the Great Depression: Cassirer, Heidegger, Ludwig Wittgenstein and Walter Benjamin. Eilenberger sees the 1920s as the last great moment of German philosophy. His four protagonists each profoundly shaped one of the major schools of thought that came to dominate our philosophical world: hermeneutics, existentialism, analytical philosophy and critical theory. It was the radical transformations of the First World War, which shook old political, cultural and moral certainties about humanity’s progress, and the fundamental upheavals that followed, that brought about the major intellectual revolutions of those years.

Time of the Magicians chronologically traces the life and work of the four philosophers, interweaving their personal and intellectual biographies. It tells their stories in parallel, jumping back and forth in a series of snappy scenes in a highly effective manner, creating a colourful and fast-paced narrative. The most intriguing parts of the book are those on Ernst Cassirer, who between 1923 and 1929 published his three-volume Philosophy of Symbolic Forms. A study of man as a sign-making and sign-reading creature, it enquires into the use of symbolic forms, most importantly language, in human life. The son of a German-Jewish bourgeois family from Breslau, Cassirer was one of the few committed democrats of his time. In 1928, he gave an address to the Hamburg senate marking the tenth anniversary of the Weimar constitution, passionately defending the embattled republic. His wife, Toni, had warned him that an open declaration of allegiance to the republic was too dangerous in the prevailing political climate, especially for a Jewish professor. Their antisemitic neighbour in Hamburg’s well-to-do Winterhude quarter had already verbally assaulted her: “Do you think you don’t disturb us? The mere sight of you – you all belong in Palestine”. After Hitler came to power, Cassirer was dismissed from his university post and the couple escaped to Switzerland.

As the Cassirers packed their suitcases, Heidegger, the “prophet of Dasein”, mounted the podium as the newly appointed rector of the University of Freiburg to declare his steadfast support for the new regime in his infamous speech, “The Self-Assertion of the German University”. His former student and mistress Hannah Arendt would later claim that he did not have a bad character, but no character at all (an exculpation). A petty bourgeois upstart from the Black Forest, Heidegger served in the First World War and, after his return, embarked on a meteoric career, first at Marburg and later Freiburg, where he assumed the chair vacated by his patron, the phenomenologist Edmund Husserl. In Being and Time (1927), on human existence, Heidegger offered a metaphysics of the nature of being. It is anxiety about one’s own finitude – which defines the human as “existence (Dasein) thrown into the world” – that makes one reflect on the possibilities of one’s own being. Yet it was his völkisch idealization of an organic rootedness in the natural environment, language and traditions, his rural romanticism, and his pathological aversion to liberal bourgeois modernity that most excited so many young intellectuals at the time.

Ludwig Wittgenstein had also served as a soldier in the war. He completed his Tractatus logico-philosophicus, a milestone of analytical philosophy on the question of what human beings can meaningfully say, and what they cannot, in an Italian prisoner of war camp. On its publication in 1921, the philosophical world celebrated him as a genius of the century. Heir to one of Vienna’s wealthiest industrial families, he then gifted his entire inheritance – hundreds of millions – to his siblings, and chose to become a primary school teacher in rural Austria. After all, he believed that his work had solved the problems of philosophy “on all essential points”. Predictably, his pupils did not live up to his expectations. Frustrated, he regularly beat them, with knuckles to the head or blows with a stick; on one occasion, he struck a boy on the head with his exercise book until it fell apart. In 1929, he got a second chance. Cambridge agreed to accept his Tractatus as a doctoral thesis. Allegedly, at the end of his viva, the forty-year-old candidate slapped his overstrained examiners, Bertrand Russell and G. E. Moore, cordially on the shoulders, and remarked: “Don’t worry, I know you’ll never understand it”. Moore wrote the examination report: “In my opinion this is a work of genius; it is in any case up to the requirements of a degree from Cambridge”. John Maynard Keynes had noted a few months earlier of their encounter in a railway carriage on the way to Cambridge: “Well, God has arrived, I met him on the 5:15 train”.

Finally, there is Walter Benjamin, characterized by Eilenberger as “a one-man Weimar”, who lived the precarious life of an independent intellectual. Benjamin had studied in Freiburg under the neo-Kantian Heinrich Rickert, together with Heidegger, whom he hated with a passion. In 1914, he conned his way out of military service. His doctoral dissertation on the “Concept of Art Criticism in German Romanticism” was widely celebrated. But too unconventional, too intellectually independent, and with too broad a range of interests for a university career, he worked as a freelance writer. Roaming Europe between Berlin, Moscow and Paris, Benjamin had an “insatiable appetite”, as the author puts it, for casinos, nightclubs and brothels. Periods of depression and self-destruction were interrupted by phases of extreme productivity. His texts span disciplinary and stylistic boundaries, ranging from the philosophy of language and literary theory to sociology and cultural history. Eilenberger offers some insightful discussions of key works, such as Benjamin’s essays on “The Task of the Translator” (1921), a reflection on the nature of language, and on “Goethe’s Elective Affinities’”(1924), a critique of the institution of bourgeois marriage (and the bourgeois life plan in general). When the Wehrmacht invaded France in 1940, where Benjamin had lived for most of the previous decade, he fled westwards and, in a hotel in the Pyrenees, just before the Spanish border, committed suicide.

Eilenberger’s biographical approach routinely follows his protagonists into the bedroom. He observes that “Of our four philosophers Cassirer is the only one whose sexuality never blossomed into an existential problem”. He discusses Wittgenstein’s homosexual adventures in the Prater park in Vienna, and quotes Heidegger writing to the then nineteen-year-old Hannah Arendt that “The demonic has struck me”. When Heidegger’s wife Elfriede cheated on him with Friedel Caesar, a physician at the Freiburg university hospital, conceiving a son, Hermann, Heidegger took it calmly. Benjamin went on a carousel of affairs; at one point, he pursued the sculptor Jula Cohn, who in turn had fallen for Benjamin’s old friend Erich Schön, with whom Benjamin’s wife Dora had had an open affair. The love of Benjamin’s life, however, was the Latvian communist theatre director Asja Lācis. In spring 1929, Dora wrote to Gershom (Gerhard) Scholem:

Walter is in a very bad way, dear Gerhard, I can’t tell you more than that because it is crushing my heart. He is entirely under Asja’s influence and doing things that the pen resists writing, and which prevent me from exchanging even a word with him. He now exists only as a head and genitals, and as you know, or can imagine, in such cases the head is quickly overcome.

Throughout the book, the author highlights the commonalities between the four philosophers. Most important was language, central to all of them in their understanding of the human condition. Charismatic thinkers, all of them embodied their philosophies; they were all, perhaps with the exception of Cassirer, cult figures in their own lifetimes. Yet, in the end, the four were in many ways radically different, and at times the author tends to overemphasize their similarities at the expense of scrutinizing these differences. The lives of the protagonists also rarely overlapped. Likewise, the chosen timeframe, 1919–29 – described as the time of “the invention of modern thought” – is arbitrary. Walter Benjamin would write some of his most important works, such as “The Work of Art in the Age of Mechanical Reproduction” and “On the Concept of History”, later; and his involvement with the Institute of Social Research, birthplace of the Frankfurt School, only began in the 1930s. Wittgenstein wrote the Tractatus before 1919, and his Philosophical Investigations after 1929. Cassirer wrote his Philosophy of the Enlightenment, The Logic of Cultural Sciences and The Myth of the State during his time in exile. Heidegger underwent his “turn” (Kehre) after this decade. In terms of their respective biographies, 1933, which affected the three philosophers who were of Jewish background immediately, might have been the more conventional but also more sensible caesura. After all, the Nazi takeover constituted an assault on the intellectual life of Germany from which the country would never recover.

Time of the Magicians is elegantly composed and beautifully narrated. A learned scholar of philosophy himself, Eilenberger has the skill to condense complex thoughts into accessible language, without being reductionist. Interweaving biography, philosophy and history, his book not only tells the story of the philosophers themselves but also offers an exciting intellectual portrait of their time. The publication of the German edition was accompanied by a debate about the current state of academic philosophy. Eilenberger, a freelance philosopher, complained in an article in Die Zeit that today’s philosophy faculties were intellectual wastelands compared to the world of those bygone giants. The issues discussed in academic philosophical journals today would interest nobody, not even the authors themselves, he argued, and offered nothing new, exciting, or original. If that seems harsh, Time of the Magicians certainly demonstrates that the interwar years were one of humanity’s greatest periods of intellectual creativity.

David Motadel teaches history at the LSE. He co-edited The Global Bourgeoisie: The rise of the middle classes in the Age of Empire, 2019, with Christof Dejung and Jürgen Osterhammel