Wittgenstein was born in Vienna in 1889, the eighth child of an extremely rich, cultivated and ill-fated family. Much of Monk’s research will be new to even avid readers of Wittgensteiniana those unacquainted with Wittgenstein’s philosophy will find Monk’s explanations helpful and unforbidding, if not exactly a piece of Sacher torte. Though Monk’s is not the authorized biography, he enjoyed the complete cooperation of Wittgenstein’s literary executors, who permitted him to quote from previously unpublished material, including diary entries written by Wittgenstein in code about his homosexuality, which has been the subject of an unseemly, irresistible debate. Suicide greatly increased both Weininger’s moral prestige and the sales of his book, which Wittgenstein read as an adolescent. A Jew and a homosexual, Weininger shot himself at 23, in the house where Beethoven, his hero, died. Weininger, a misogynist and anti-Semite, believed it was man’s duty to conquer the flesh and to discover and realize his genius-or to kill himself. The book’s subtitle, “The Duty of Genius,” is taken from Otto Weininger’s “Sex and Character,” which Monk believes is the source of many of Wittgenstein’s attitudes toward life and love. Though baptized a Catholic, he was of Jewish descent, a heritage he sometimes blamed for his moral and mental inadequacies in language reminiscent of “Mein Kampf.” (Curiously, Hitler and Wittgenstein attended the same school for a year there’s no evidence that they met.) He was equally hard on himself, a master of self-laceration who often contemplated suicide. One young boy told his diary: “Witkinstein (sic) is an impossible person everytime you say anything he says ‘No No that’s not the point.’ ” He reminded one student of “the Norse God Baldur, blue-eyed and fair-haired, with a beauty that had nothing sensual about it.” Others were less enthusiastic.

He is passionate, tormented, misunderstood, a man so singular that virtually everyone who ever knew him, from Bertrand Russell to the man who delivered peat to his cottage in Ireland, remembered and wrote about him.

He’s the “Mad Genius” as sent by Central (European) Casting, the savior of British philosophy or its trivializer. Since his death in 1951, however, he has emerged as one of the best known and least comprehended contemporary thinkers.

It’s hard to imagine a more unwilling celebrity than this profoundly serious man who shunned publicity and devoted his life to the pursuit of clarity. The philosopher Ludwig Wittgenstein may be the most famous obscure intellectual of the century.

Ludwig wittgenstein the duty of genius