In Weimar Berlin he fell into the circle of the Comintern agent Willi Münzenberg, through whom he met the leading German Communists [and fellow-travellers] of the era, including Johannes Becher, Hanns Eisler and Bertolt Brecht.

[7] In 1861, Lipót married Karolina Schon, the daughter of a prosperous timber merchant, and their son Henrik was born on 18 August 1869 in the town of Miskolc in northeastern Hungary.

In March 1926, he wrote a letter to his parents telling them that he was going to Mandate Palestine for a year to work as an assistant engineer in a factory, in order to gain experience to help him obtain a job in Austria.

Much later he would describe how in the train station of Kharkiv, "[Ukrainian peasant women] held up to the carriage windows horrible infants with enormous wobbling heads, sticklike limbs, and swollen, pointed bellies" as a result of the widespread malnutrition.

He collected evidence of the direct involvement of Fascist Italy and Nazi Germany on Franco's side, which at that time the Nationalists rebels were still trying to conceal.

He took refuge in the house of retired zoologist Sir Peter Chalmers Mitchell, and they were both arrested by Franco's chief propagandist, Luis Bolín, who had sworn that if he ever got his hands on Koestler, he would "shoot him like a dog".

As he noted in his autobiography, his estranged wife Dorothy Ascher had greatly contributed to saving his life by intensive, months-long lobbying on his behalf in Britain.

The French government first detained Koestler at Stade Roland Garros until he was moved to Le Vernet Internment Camp among other "undesirable aliens", most of them refugees.

The region had its own intellectual circle, which would have been sympathetic to Koestler: Williams-Ellis' wife, Amabel, a niece of Lytton Strachey, was also a former communist; other associates included Rupert Crawshay-Williams, Michael Polanyi, Storm Jameson and, most significantly, Bertrand Russell, who lived close by.

[48] In June 1950, Koestler delivered a major anti-communist speech in Berlin under the auspices of the Congress for Cultural Freedom, an organisation funded (though he did not know this) by the Central Intelligence Agency (CIA) of the United States.

In early 1960, on his way back from a conference in San Francisco, Koestler interrupted his journey at the University of Michigan, Ann Arbor, where some experimental research was going on with hallucinogens.

In 1962, along with his agent, A D Peters and the editor of The Observer, David Astor, Koestler set up a scheme to encourage prison inmates to engage in arts activities and to reward their efforts.

In 1965 he married Cynthia in New York;[60] they moved to California, where he participated in a series of seminars at the Center for Advanced Study in the Behavioral Sciences at Stanford University.

In his article "Return Trip to Nirvana", published in 1967 in the Sunday Telegraph, Koestler wrote about the drug culture and his own experiences with hallucinogens.

During the final years of his life, Koestler, Brian Inglis and Tony Bloomfield established the KIB Society (named from the initials of their surnames) to sponsor research "outside the scientific orthodoxies".

In his capacity as vice-president of the Voluntary Euthanasia Society, later renamed Exit, Koestler wrote a pamphlet on suicide, outlining the case both for and against, with a section dealing specifically with how best to do it.

The purpose of this note is to make it unmistakably clear that I intend to commit suicide by taking an overdose of drugs without the knowledge or aid of any other person.

Should this attempt fail and I survive it in a physically or mentally impaired state, in which I can no longer control what is done to me, or communicate my wishes, I hereby request that I be allowed to die in my own home and not be resuscitated or kept alive by artificial means.

I wish my friends to know that I am leaving their company in a peaceful frame of mind, with some timid hopes for a de-personalised after-life beyond due confines of space, time and matter and beyond the limits of our comprehension.

Double suicide has never appealed to me, but now Arthur's incurable diseases have reached a stage where there is nothing else to do.The funeral was held at the Mortlake Crematorium in South London on 11 March 1983.

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.

[citation needed] In his book The Case of the Midwife Toad (1971) Koestler defended the biologist Paul Kammerer, who claimed to have found experimental support for Lamarckian inheritance.

[95] According to an article in the Skeptical Inquirer, Koestler was an "advocate of Lamarckian evolution – and a critic of Darwinian natural selection as well as a believer in psychic phenomena".

[96] In addition to his specific critiques of neo-Darwinism, Koestler was opposed to what he saw as dangerous scientific reductionism more generally, including the behaviourism school of psychology, promoted in particular by B. F. Skinner during the 1930s.

[97] Koestler assembled a group of high-profile antireductionist scientists, including C. H. Waddington, W. H. Thorpe, and Ludwig von Bertalanffy, for a meeting at his retreat in Alpbach in 1968.

[97] Although he never gained significant credibility as a scientist, Koestler published a number of works at the border between science and philosophy, such as Insight and Outlook, The Act of Creation, and The Ghost in the Machine.

In an interview published in the British newspaper The Jewish Chronicle in 1950, he argued that Jews should either emigrate to Israel or assimilate completely into the majority cultures they lived in.

[104][105][106] In The Thirteenth Tribe (1976), Koestler advanced a theory that Ashkenazi Jews are descended not from the Israelites of antiquity but from the Khazars, a Turkic people in the Caucasus that converted to Judaism in the 8th century and was later forced westwards.

[107] Much of Arthur Koestler's work was funded and distributed secretly by a covert propaganda wing of the UK Foreign Office, known as the Information Research Department (IRD).

"[115] NB The books The Lotus and the Robot, The God that Failed, and Von weissen Nächten und roten Tagen, as well as his numerous essays, all may contain further autobiographical information.