Ludwig Wittgenstein
Austrian-born, naturalised British philosopher (1889–1951), born in Vienna into one of the wealthiest families in Europe, initially trained in aeronautical engineering in Manchester before becoming drawn to logic and moving to Cambridge to study under Bertrand Russell, who quickly considered him the most brilliant student he had ever had. He wrote much of his first and only book published during his lifetime, the Tractatus Logico-Philosophicus (1921), while serving as a soldier in the First World War, even finishing it in an Italian prisoner-of-war camp. The Tractatus proposes that language functions as a 'logical picture' of reality: meaningful propositions are those representing possible facts of the world, and anything that does not fulfil this function — metaphysics, ethics, aesthetics, religion — falls outside the bounds of what can be meaningfully said and can only be 'shown', culminating in his famous closing maxim: 'whereof one cannot speak, thereof one must be silent'. Convinced he had definitively solved philosophy's problems, he abandoned the field for over a decade, working as a rural schoolteacher in Austria and as an architect, until returning to Cambridge in 1929 and gradually developing a radically different philosophy, published posthumously as Philosophical Investigations (1953): now the meaning of a word is not a fixed logical relation to the world but its use within various 'language games', socially shared forms of life, and many traditional philosophical problems arise from using language outside the context in which it makes sense — an 'illness' that philosophy itself must cure by exposing the conceptual tangles that generate it. These two works defined, largely independently of one another, two of the most influential traditions in twentieth-century analytic philosophy.