Ludwig Josef Johann Wittgenstein was born on 26 April 1889 in Vienna, the son of Karl Wittgenstein, a wealthy steel industrialist. He studied at the Technische Hochschule in Berlin-Charlottenburg whence he moved in 1908 to the University of Manchester to study aeronautics where he designed a primitive jet-turbine engine. The mathematics required for his studies in engineering brought him to consider the philosophy of mathematics and to seek out Bertrand Russell at Trinity College Cambridge, with whom he studied, at first on an unofficial basis. In January 1912 he was admitted to Trinity where he spent five terms before moving to Skjolden in Norway, where he thought he might work on logic in peaceful surroundings.
At the outbreak of war, Wittgenstein volunteered for the Austrian army, fighting on the Eastern and Southern fronts before he was captured by the Italians in 1918. During his incarceration, he was able to finish the work which was to become the Tractatus Logico-Philosophicus, later published in 1922. The war clearly had a profound effect on Wittgenstein, who, shortly after his release gave away the fortune that he had inherited from his father and resolved to lead a life of simplicity.
Wittgenstein now took up the career of schoolteacher, holding positions in a number of schools in Lower Austria, but he was not always sufficiently sensitive to the needs of the slower children. In 1926 he was forced to leave after hitting a young pupil, and he returned to Vienna to design a house for his sister.
In 1929, Wittgenstein returned to Cambridge on the prompting of Frank Ramsey and in June received the degree of PhD, submitting the Tractatus as his dissertation. In the following year he was elected to a senior research fellowship of Trinity College, which he held for six years. At the same time he was a lecturer in the Moral Sciences faculty, during which time the Blue and Brown books were dictated to his pupils. In 1939 he succeeded G E Moore as Knightbridge Professor of Philosophy. During WWII he worked as a porter in Guy's hospital and as a laboratory assistant in a laboratory in Newcastle looking into shell shock. He returned to his duties in Cambridge at the end of the war, but resigned from his chair in 1947. In 1948 and 49 he lived in Ireland but returned to England, dying in Cambridge in 1951.