Koestler: The Literary and Political Odyssey of a Twentieth-Century Skeptic by Michael Scammell Random House, 689 pp., $35.00

He began his education in the twilight of the Austro-Hungarian Empire, at an experimental kindergarten in Budapest. His mother was briefly a patient of Sigmund Freud’s. In interwar Vienna he wound up as the personal secretary of Vladimir Jabotinsky, one of the early leaders of the Zionist movement. Traveling in Soviet Turkmenistan as a young and ardent Communist sympathizer, he ran into Langston Hughes. Fighting in the Spanish civil war, he met W.H. Auden at a “crazy party” in Valencia, before winding up in one of Franco’s prisons. In Weimar Berlin he fell into the circle of the infamous Comintern agent Willi Münzenberg, through whom he met the leading German Communists of the era: Johannes Becher, Hanns Eisler, Bertolt Brecht. Afraid of being caught by the Gestapo while fleeing France, he borrowed suicide pills from Walter Benjamin. He took them several weeks later when it seemed he would be unable to get out of Lisbon, but didn’t die (though Benjamin, denied passage into Spain at the French border, took them and did).

Along the way he had lunch with Thomas Mann, got drunk with Dylan Thomas, made friends with George Orwell, flirted with Mary McCarthy, and lived in Cyril Connolly’s London flat. In 1940, Koestler was released from a French detention camp, partly thanks to the intervention of Harold Nicholson and Noël Coward. In the 1950s, he helped found the Congress for Cultural Freedom, together with Mel Lasky and Sidney Hook. In the 1960s, he took LSD with Timothy Leary. In the 1970s, he was still giving lectures that impressed, among others, the young Salman Rushdie.

It is difficult, in other words, to think of a single important twentieth-century intellectual who did not cross paths with Arthur Koestler, or a single important twentieth-century intellectual movement that Koestler did not either join or oppose. From progressive education and Freudian psychoanalysis through Zionism, communism, and existentialism to psychedelic drugs, parapsychology, and euthanasia, Koestler was fascinated by every philosophical fad, serious and unserious, political and apolitical, of his era.

Nor were these shallow passions. His belief in communism led him to fight in Spain and travel in the USSR. His Zionism led him to a kibbutz near Haifa. At different times, he advocated the use of violence, whether to bring about a Communist utopia or to create the state of Israel. Even when he turned against his previous causes (and against his previous friends who still believed in them) he did so with real fervor. He is, after all, best known as an anti-Communist, not as a Communist, largely because of his best and most influential book, Darkness at Noon, a fictional account of the interrogation of a leading member of an unnamed Communist party. His involvement with Revisionist Zionism is also probably less well known than The Thirteenth Tribe, a book that argues that modern European Jews are descended from the Central Asian Khazars, and not from the Jews who lived in the Palestine of antiquity—a thesis which, whatever its merits, is…