Ludwig Josef Johann Wittgenstein was an Austrian-British philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.
From 1929 to 1947, Wittgenstein taught at the University of Cambridge. During his lifetime he published just one slim book (the 75-page Tractatus Logico-Philosophicus), one article ("Some Remarks on Logical Form", 1929), one book review and a children's dictionary. His voluminous manuscripts were edited and published posthumously. Philosophical Investigations appeared as a book in 1953, and has since come to be recognized as one of the most important works of philosophy in the 20th century. His teacher, Bertrand Russell, described Wittgenstein as "perhaps the most perfect example I have ever known of genius as traditionally conceived; passionate, profound, intense, and dominating."
A survey among American university and college teachers ranked the 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". The Investigations also ranked 54th on a list of most influential twentieth-century works in cognitive science prepared by the University of Minnesota's Center for Cognitive Sciences. However, in the words of his friend Georg Henrik von Wright, he believed that "his ideas were generally misunderstood and distorted even by those who professed to be his disciples. He doubted he would be better understood in the future. He once said he felt as though he was writing for people who would think in a different way, breathe a different air of life, from that of present-day men."