Ludwig Josef Johann Wittgenstein ( ; ; 26 April 1889 – 29 April 1951) was an Austro-British philosopher who worked primarily in logic, philosophy of mathematics, philosophy of mind, and philosophy of language. Despite his position, only one book of his philosophy was published during his life: the 75-page Logisch-Philosophische Abhandlung (Logical-Philosophical Treatise, 1921), which appeared, together with an English translation, in 1922 under the Latin title Tractatus Logico-Philosophicus. His only other published works were an article, "Some Remarks on Logical Form" (1929); a review of The Science of Logic by P. Coffey; and a children's dictionary. His voluminous manuscripts were edited and published posthumously. The first and best-known of this posthumous series is the 1953 book Philosophical Investigations. A 1999 survey of American university and college teachers ranked Philosophical Investigations as the most important book of 20th-century philosophy, standing out as "the one crossover masterpiece in twentieth-century philosophy, appealing across diverse specializations and philosophical orientations".
His philosophy is often divided into an early period, exemplified by the Tractatus, and a later period, articulated primarily in the Philosophical Investigations. The "early Wittgenstein" was concerned with the logical relationship between propositions and the world, and he believed that by providing an account of the logic underlying this relationship, he had solved all philosophical problems. The "later Wittgenstein" rejected many of the assumptions of the Tractatus, arguing that the meaning of words is best understood as their use within a given language game. More precisely, Wittgenstein wrote, "For a large class of cases of the employment of the word 'meaning'—though not for all—this word can be explained in this way: the meaning of a word is its use in the language."
Born in Vienna into one of Europe's richest families, he inherited a fortune from his father in 1913. Before World War I, he "made a very generous financial bequest to a group of poets and artists chosen by Ludwig von Ficker, the editor of Der Brenner, from artists in need. These included [Georg] Trakl as well as Rainer Maria Rilke and the architect Adolf Loos", and also the painter Oskar Kokoschka. "In autumn 1916, as his sister reported, 'Ludwig made a donation of a million crowns [equivalent to about $ million in ] for the construction of a 30 cm mortar. Later, in a period of severe personal depression after World War I, he gave away his remaining fortune to his brothers and sisters. Three of his four older brothers died by separate acts of suicide.
Wittgenstein left academia several times: serving as an officer on the front line during World War I, where he was decorated a number of times for his courage; teaching in schools in remote Austrian villages, where he encountered controversy for using sometimes violent corporal punishment on both girls and boys (see, for example, the Haidbauer incident), especially during mathematics classes; working during World War II as a hospital porter in London; and working as a hospital laboratory technician at the Royal Victoria Infirmary in Newcastle upon Tyne.
Background
The Wittgensteins
left|thumb|[[Karl Wittgenstein was one of the richest men in Europe. an Ashkenazi Jewish land agent who lived with his wife, Brendel Simon, in Bad Laasphe in the Principality of Wittgenstein, Westphalia. In July 1808, Napoleon issued a decree that everyone, including Jews, must adopt an inheritable family surname, so Meier's son, also Moses, took the name of his employers, the Sayn-Wittgensteins, and became Moses Meier Wittgenstein. His son, Hermann Christian Wittgenstein — who took the middle name "Christian" to distance himself from his Jewish background — married Fanny Figdor, also Jewish, who converted to Protestantism just before they married, and the couple founded a successful business trading in wool in Leipzig. Ludwig's grandmother Fanny was a first cousin of the violinist Joseph Joachim.
They had 11 children – among them Wittgenstein's father. Karl Otto Clemens Wittgenstein (1847–1913) became an industrial tycoon, and by the late 1880s was one of the richest men in Europe, with an effective monopoly on Austria's steel cartel. Thanks to Karl, the Wittgensteins became the second wealthiest family in the Austro-Hungarian Empire, only the Rothschilds being wealthier. Karl Wittgenstein was viewed as the Austrian equivalent of Andrew Carnegie, with whom he was friends, and was one of the wealthiest men in the world by the 1890s. His mother was Leopoldine Maria Josefa Kalmus, known among friends as "Poldi". Her father was a Bohemian Jew, and her mother was an Austrian-Slovene Catholic—she was Wittgenstein's only non-Jewish grandparent. Poldi was an aunt of the Nobel Prize laureate Friedrich Hayek on his maternal side. Wittgenstein was born at 8:30 on 26 April 1889 in the "Villa Wittgenstein" at what became Neuwaldegger Straße 38 in the suburban parish Neuwaldegg outside Vienna.
thumb|upright|left|Ludwig, 1890s
Karl and Poldi had nine children in all—four girls: Hermine, Margaret (Gretl), Helene, and a fourth daughter Dora who died as a baby; and five boys: Johannes (Hans), Kurt, Rudolf (Rudi), Paul—who became a concert pianist despite losing an arm in World War I—and Ludwig, who was the youngest of the family.
thumb|Ludwig sitting in a field as a child
Wittgenstein and his siblings were brought up in the Roman Catholic faith of their mother. and Johannes Brahms and Gustav Mahler gave regular concerts in the family's numerous music rooms. According to John King, Wittgenstein "was always immaculately neat and tidy, small of stature and with piercing blue eyes under a shock of curly hair." Ludwig Wittgenstein himself had absolute pitch, and his devotion to music remained vitally important to him throughout his life; he made frequent use of musical examples and metaphors in his philosophical writings, and he was unusually adept at whistling lengthy and detailed musical passages. He also learnt to play the clarinet in his 30s. A fragment of music (three bars), composed by Wittgenstein, was discovered in one of his 1931 notebooks, by Michael Nedo, director of the Wittgenstein Institute in Cambridge.
Family temperament and the brothers' suicides
thumb|upright|left|From left, Helene, Rudi, Hermine, Ludwig (the baby), [[Margaret Stonborough-Wittgenstein|Gretl, Paul, Hans, and Kurt, around 1890]]
Ray Monk writes that Karl's aim was to turn his sons into captains of industry; they were not sent to school lest they acquire bad habits but were educated at home to prepare them for work in Karl's industrial empire. Three of the five brothers later committed suicide. Psychiatrist Michael Fitzgerald argues that Karl was a harsh perfectionist who lacked empathy, and that Wittgenstein's mother was anxious and insecure, unable to stand up to her husband. Johannes Brahms said of the family, whom he visited regularly: The family appeared to have a strong streak of depression running through it. Anthony Gottlieb tells a story about Paul practising on one of the pianos in the Wittgensteins' main family mansion, when he suddenly shouted at Ludwig in the next room: