Arthur Koestler was a Hungarian born polymath who became a British citizen in the 1950s and died in tragic circumstances in 1983. Three times nominated for the Nobel Prize, he was an iconoclastic figure who threw down the gauntlet to the left wing, the scientific establishment, Zionism and Hindu spiritualism. He was passionate in his campaigns against totalitarian tendencies, and wrote powerfully in defence of his stand. His novel, 'Darkness at Noon', published in Britain in 1940 and written with reference to the show trials of the Stalinist period, was ranked in 1998 as the eighth best novel of the century. Similarly his powerful biographical essay in 'The God that Failed' ranks as a classic in the genre of confessional writings by ex-communists. 'The Sleepwalkers', his account of scientific discovery and human creativity based on the lives of Copernicus, Kepler and Galileo, published in 1959, demonstrated how the progress of science and human knowledge did not follow a smooth linear path. Koestler's exposition of the psychological and ideological factors affecting scientific discovery conceptually anticipated Thomas Kuhn's work on the structure of scientific revolutions. Koestler's 'Ghost in the Machine', published 1967, was a refreshing critique of the neo-Darwinian approach to evolution and the theories of the mind, followed up two years later with 'Beyond Reductionism'. He visited India 'in the mood of a pilgrim' but his account on Gandhi in 'The Lotus and the Robot' was so scathing that the book was banned in India. A Jew by birth and an early supporter of Zionism, he came to be ashamed by the actions of the State of Israel and arguably his most provocative book, 'The Thirteenth Tribe', proposing that European Jews had no racial claim to land in Palestine, was published in 1976. An advocate of euthanasia, Koestler killed himself in his London home in Kensington, in an act of double suicide with his wife. He left a note in which he expressed "some timid hopes for a depersonalised after-life". His is a forgotten name today, even though on his seventieth birthday in 1975, 'The Times' compared him with George Orwell, with whom 'he shares the status of one of the most cogent and brilliant essayists of our time'.

David Cesarani, professor of Jewish History at the University of Southampton, has written a voluminous and pedantically chronological account of Koestler's life and thought. As a biographer he foists on his subject a number of his own prejudices, as a result of which the anglophile and convivial Koestler is painted as an outsider frustrated by a high-living and lazy British intellectual elite. However Koestler acquired a sense of Englishness evident in remarks such as these, 'If even after thirty years in this country, I still sometimes feel a stranger among its natives, the moment I set foot on the Continent I feel British to the bone'. Moreover, Koestler was embraced and treated frankly and affectionately by the English writers of his day: Orwell spent a holiday in Koestler's Welsh cottage and chided him for his hedonistic streak; Muggeridge famously said that Koestler was 'all antennae and no head'; Cyril Connolly was a life-long friend. In contrast, Cesarani has a chip on his shoulder about British intellectuals that he transfers to his subject, "Koestler's cosmopolitanism, volcanic energy and genuine anit-Facism must have made him an uncomfortable house guest for such louche, posturing, ineffectual under-achievers as Quennel and Connolly…".

Cesarani also interprets Koestler as the 'quintessential modern Jew'. "For the deracinated Jew, temporarily cut off from his past and his people by his own volition, for whom the USSR now seemed something less than a new promised land, the Communist Party and the spirit of international brotherhood substituted as home. His ever-deepening involvement in the party was an expression of his search for identity and belonging, a quest that was typical of so many estranged Jews in the 1930s". This theme of quintessential Jewishness is pursued with such single-mindedness that even Koestler's statements and actions disassociating himself from central European Jewry are regarded as 'acts of deception'! One wonders why, after chronicling Koestler's hedonistic lifestyle, misogynism, womanising and drunken revelry, Cesarani should still wish to embrace him in the Jewish fold.

'The Homeless Mind' rapidly attained notoriety because its spicy details of Koestler's private life were serialised in the British press. At the time another Koestler biographer publicly questioned how Cesarani obtained access to the writer's papers, suggesting some impropriety on the issue of literary property rights. Cesarani's extensive scholarship, in particular the commendable use of KGB archives, emerges less a labour of love and more an exercise in biographical opportunism. The incident involving Michael Foot's wife has dented Koestler's reputation, no doubt contributing to the University of Edinburgh's decision to remove a sculpture of Koestler's head from display in 1999.

Arthur Koestler's life provides important information on the history of Zionism. As a Zionist activist at the University of Vienna in the 1920s, he witnessed the struggle between the anti and pro socialist wings of the movement. He did not complete his university education, instead reading widely on mainly scientific topics. The ambitions of the Zionist movement at the time were to create a Jewish homeland but not necessarily in Palestine. Proposals of a tract of land in East Africa were mooted, and Koestler, who had been selected on his merits as a science journalist on a polar zeppelin expedition, offered an alternative. In December 1929 at a meeting in Paris of the anti-socialist Jabotinsky faction of the Zionist movement (also known as Revisionist Zionists) , Cesarani notes that Koestler came up "with an extraordinary proposal that he stake a claim over any as yet undiscovered territory in the Arctic on behalf of the future Jewish state". It is likely that Koestler was flying a kite, but it is an indication that Palestine was not regarded as a legitimate demand in Zionist circles in the first instance.

Koestler visited Palestine in 1944, acting as an intermediary between the socialist faction under Weizmann in London, and Menachim Begin, Jabotinsky's successor and head of Irgun in Palestine. According to Cesarini, Weizmann was concerned that Irgun's assassination of Lord Moyne, the Colonial Secretary and friend of Winston Churchill, would cause irreparable damage to the Zionist cause. "Weizmann knew that Koestler had once been close to Jabotinsky and therefore had good credentials with the leaders of the underground. He asked him to track down Begin, who was in hiding, and try to persuade him to suspend terrorist operations against the British". A clandestine meeting took place but Irgun was not prepared to negotiate. The socialist Zionists however thought that Koestler had been converted to Irgun's cause, not without justification, because in May 1947 he wrote an article in the New Statesman which makes apt reading fifty-four years later: "Political terrorism has not been invented by them [Irgun]; it is as old as injustice and oppression, which is its cause".

Koestler's profound disillusionment with Israel commenced almost immediately after the entity was established. In August 1947 he confessed "Marvelling at the fool I had been a year before …Jabotinsky, Revisionism, Irgun, was still an undigested lump in my stomach. When I touched upon these subjects I descended from maturity to adolescent emotion…". Cesarini writes that by July 1948 Koestler was forming a very different picture of the war between the Israelis and the Arabs: "It seemed to him a grotesque shadow play. The Israelis claimed to have defeated an invasion by five Arab armies, but actually the incursions had limited objectives and were uncoordinated. He had learned …that King Abdullah of Jordan had even concluded a secret agreement with the Israelis and the British not to push the Arab Legion beyond a certain point…Meanwhile, the Israeli authorities smuggled in arms, but attacked the Irgun for doing the very same." In Koestler's own words, "What my eyes fell upon was corruption and the smell of death".

Koestler met the first Prime Minister of Israel Ben Gurion and challenged him to explain the vision for the future - "was it to be Levantine, or Western or Orthodoxy?" If the latter, it meant a regression to the first century AD. At this Ben Gurion retorted that Koestler had no notion of what Jewish tradition meant. Koestler was bitter that Ben Gurion had "treated me…as a stranger and goi". Koestler was also caught up in an incident in a Haifa cafe in which a gunman broadcast that the only good non-Jew was a dead one. Koestler, with his famous mental antennae, could foresee that Israel's politicians were creating a fascist state. Notwithstanding Cesarani's insistence that Koestler's act of turning his back to Isreal made him ' a wandering Jew', it is worth noting what the subject himself has to say at this point of his life: "I am not really a Jew and haven't got the feelings of one". Koestler's views on Israel can be found in his book 'Promise and fulfilment: 1917-1949'. He tackled head-on issues such as the dilemma of dual loyalty facing Diaspora Jews after the establishment of Israel, and deemed Judaism as 'a perpetuum mobile for generating anti-Semitism'. Jewish religious observance amounted to 'the art of cheating the Lord'. The biographer Cesarani however comes to the bizarre conclusion that Koestler's attempt to flee Judaism was "the quintessential act of the modern Jew: it was, itself, a badge of identity".

The life and thought of Koestler provides an opportunity to raise wider, more interesting issues on an intellectual oddsey in the twentieth century. He had a creative insight that man was a more ennobled being than the creature envisaged in the Marxist, Darwinist and psyochoanalytical models of man. He drank from many fountains and searched for perfection in the world of ideas and the world of the flesh. Cesarini does not give enough attention to Koestler's science books, and it is significant that with this background - or despite it - Koestler's intuition led him to believe that there was a non-material reality and his entire property was bequested to found a Chair in Parapsychology at the Edinburgh University.