Ludwig Wittgenstein

Ludwig Josef Johann Wittgenstein (April 26, 1889 – April 29, 1951) was an Austrian philosopher who contributed several ground-breaking ideas to philosophy, primarily in the foundations of logic, the philosophy of mathematics, the philosophy of language, and the philosophy of mind. His influence has been wide-ranging, placing him among the most significant philosophers of the 20th century.

Life
Ludwig Wittgenstein was born in Vienna on April 26, 1889, to Karl and Leopoldine Wittgenstein. He was the youngest of eight children, born into one of the most prominent and wealthy families in the Austro-Hungarian empire. His father's parents, Hermann Christian and Fanny Wittgenstein, were born into Jewish families but later converted to Protestantism, and after they moved from Saxony to Vienna in the 1850s, assimilated themselves into the Viennese Protestant professional classes. Ludwig's father, Karl Wittgenstein, became an industrialist and went on to make a fortune in iron and steel. Ludwig's mother Leopoldine, born Kalmus, was an aunt of the Nobel Prize laureate Friedrich von Hayek. Despite Karl's Protestantism, and the fact that Leopoldine's father was Jewish, the Wittgenstein children were baptized as Roman Catholics—the faith of their maternal grandmother—and Ludwig was given a Roman Catholic burial by his friends upon his death.

Early life
Ludwig grew up in a household that provided an exceptionally intense environment for artistic and intellectual achievement. His parents were both very musical and all their children were artistically and intellectually gifted. Karl Wittgenstein was a leading patron of the arts, and the Wittgenstein house hosted many figures of high culture &mdash; above all, musicians. The family was often visited by artists such as Johannes Brahms and Gustav Mahler. Ludwig's older brother Paul Wittgenstein went on to become a world-famous concert pianist, even after losing his right arm in World War I. Ludwig himself did not have prodigious musical talent, but nonetheless had absolute pitch and his devotion to music remained vitally important to him throughout his life &mdash; he made frequent use of musical examples and metaphors in his philosophical writings, and was said to be unusually adept at whistling lengthy and detailed musical passages. He also played the clarinet and is said to have remarked that he approved of this instrument because it took a proper role in the orchestra.

His family also had a history of intense self-criticism, to the point of depression and suicidal tendencies. Three of his four brothers committed suicide. The eldest of the brothers, Hans &mdash; a musical prodigy who started composing at age four &mdash; killed himself in April 1902, in Havana, Cuba. The third son, Rudolf, followed in May 1904 in Berlin. Their brother Kurt shot himself at the end of World War I, in October 1918, when the Austrian troops he was commanding deserted en masse.

Until 1903, Ludwig was educated at home; after that, he began three years of schooling at the Realschule in Linz, a school emphasizing technical topics. Adolf Hitler was a student there at the same time, when both boys were 14 or 15 years old. Ludwig was interested in physics and wanted to study with Ludwig Boltzmann, whose collection of popular writings, including an inspiring essay about the hero and genius who would solve the problem of heavier-than-air flight ("On Aeronautics") was published during this time (1905). Boltzmann committed suicide in 1906, however.

In 1906, Wittgenstein began studying mechanical engineering in Berlin, and in 1908 he went to the Victoria University of Manchester to study for his doctorate in engineering, full of plans for aeronautical projects. He registered as a research student in an engineering laboratory, where he conducted research on the behaviour of kites in the upper atmosphere, and worked on the design of a propeller with small jet engines on the end of its blades. During his research in Manchester, he became interested in the foundations of mathematics, particularly after reading Bertrand Russell's Principles of Mathematics and Gottlob Frege's Grundgesetze. In the summer of 1911, Wittgenstein visited Frege, and after having corresponded with him for some time, he was advised by Frege to attend the University of Cambridge to study under Russell.

In October 1911, Wittgenstein arrived unannounced at Russell's rooms in Trinity College, and was soon attending his lectures and discussing philosophy with him at great length. He made a great impression on Russell and G. E. Moore and started to work on the foundations of logic and mathematical logic. Russell was increasingly tired of philosophy, and saw Wittgenstein as a successor who would carry on his work. During this period, Wittgenstein's other major interests were music and travelling, often in the company of David Pinsent, an undergraduate who became a firm friend. He was also invited to join the elite secret society, the Cambridge Apostles, which Russell and Moore had both belonged to as students. Whilst in Cambridge Wittgenstein often liked to go to the cinema.

In 1913, Wittgenstein inherited a large fortune when his father died. He donated some of it, initially anonymously, to Austrian artists and writers, including Rainer Maria Rilke and Georg Trakl. In 1914 he went to visit Trakl when the latter wanted to meet his benefactor, but Trakl killed himself days before Wittgenstein arrived.

Although he was invigorated by his study in Cambridge and his conversations with Russell, Wittgenstein came to feel that he could not get to the heart of his most fundamental questions while surrounded by other academics. In 1913, he retreated to the relative solitude of the remote village of Skjolden at the bottom of the Sognefjord in Norway. Here he rented the second floor of a house and stayed for the winter. The isolation from academia allowed him to devote himself entirely to his work, and he later saw this period as one of the most passionate and productive times of his life. While there, he wrote a ground-breaking work in the foundations of logic, a book entitled Logik, which was the immediate predecessor and source of much of the Tractatus Logico-Philosophicus.

World War I
The outbreak of World War I in the next year took him completely by surprise, as he was living a secluded life at the time. He volunteered for the Austro-Hungarian army as a private soldier, first serving on a ship and then in an artillery workshop. In 1916, he was sent as a member of a howitzer regiment to the Russian front, where he won several medals for bravery. The diary entries of this time reflect his contempt for the baseness, as he saw it, of his fellow soldiers. Throughout the war, Wittgenstein kept notebooks in which he frequently wrote philosophical and religious reflections alongside personal remarks. The notebooks reflect a profound change in his religious life: a militant atheist during his stint at Cambridge, Wittgenstein discovered Leo Tolstoy's The Gospel in Brief at a bookshop in Galicia. He devoured Tolstoy's commentary and became an evangelist of sorts; he carried the book everywhere he went and recommended it to anyone in distress (to the point that he became known to his fellow soldiers as "the man with the gospels"). Although Monk notes that Wittgenstein began to doubt by at least 1937, and that by the end of his life he said he could not believe Christian doctrines (although religious belief remained an important preoccupation), this is not contrary to the influence that Tolstoy had on his philosophy. Wittgenstein's other religious influences include Saint Augustine, Fyodor Dostoevsky, and most notably Søren Kierkegaard, whom Wittgenstein referred to as "a saint".

Developing the Tractatus
Wittgenstein's work on Logik began to take on an ethical and religious significance. With this new concern with the ethical, combined with his earlier interest in logical analysis, and with key insights developed during the war (such as the so-called "picture theory" of propositions), Wittgenstein's work from Cambridge and Norway was transfigured into the material that eventually became the Tractatus. In 1918, toward the end of the war, Wittgenstein was promoted to reserve officer (lieutenant) and sent to northern Italy as part of an artillery regiment. On leave in the summer of 1918, he received a letter from David Pinsent's mother telling Wittgenstein that her son had been killed in an airplane accident. Suicidal, Wittgenstein went to stay with his uncle Paul, and completed the Tractatus, which was dedicated to Pinsent. In a letter to Mrs Pinsent, Wittgenstein said "only in him did I find a real friend". The book was sent to publishers at this time, without success.

In October, Wittgenstein returned to Italy and was captured by the Italians. Through the intervention of his Cambridge friends (Russell, Keynes and Pinsent had corresponded with him throughout the war, via Switzerland), Wittgenstein managed to get access to books, prepare his manuscript, and send it back to England. Russell recognized it as a work of supreme philosophical importance, and after Wittgenstein's release in 1919, he worked with Wittgenstein to get it published. An English translation was prepared, first by Frank P. Ramsey and then by C. K. Ogden, with Wittgenstein's involvement. After some discussion of how best to translate the title, G. E. Moore suggested Tractatus Logico-Philosophicus, an allusion to Baruch Spinoza's Tractatus Theologico-Politicus. Russell wrote an introduction, lending the book his reputation as one of the foremost philosophers in the world.

However, difficulties remained. Wittgenstein had become personally disaffected with Russell, and he was displeased with Russell's introduction, which he thought evinced fundamental misunderstandings of the Tractatus. Wittgenstein grew frustrated as interested publishers proved difficult to find. To add insult to injury, those publishers who were interested proved to be so mainly because of Russell's introduction. At last, Wittgenstein found publishers in Wilhelm Ostwald's journal Annalen der Naturphilosophie, which printed a German edition in 1921, and in Routledge Kegan Paul, which printed a bilingual edition with Russell's introduction and the Ramsey-Ogden translation in 1922.

The "lost years": life after the Tractatus
At the same time, Wittgenstein was a profoundly changed man. He had embraced the Christianity that he had previously opposed, faced harrowing combat in World War I, and crystallized his intellectual and emotional upheavals with the exhausting composition of the Tractatus. It was a work which transfigured all of his past work on logic into a radically new framework that he believed offered a definitive solution to all the problems of philosophy. These changes in Wittgenstein's inner and outer life left him both haunted and yet invigorated to follow a new, ascetic life. One of the most dramatic expressions of this change was his decision in 1919 to give away his portion of the family fortune that he had inherited when his father had died. The money was divided between his sisters Helene and Hermine and his brother Paul, and Wittgenstein insisted that they promise never to give it back. He felt that giving money to the poor could only corrupt them further, whereas the rich would not be harmed by it.

Since Wittgenstein thought that the Tractatus had solved all the problems of philosophy, he left philosophy and returned to Austria to train as a primary school teacher. He was educated in the methods of the Austrian School Reform Movement which advocated the stimulation of the natural curiosity of children and their development as independent thinkers, instead of just letting them memorize facts. Wittgenstein was enthusiastic about these ideas but ran into problems when he was appointed as an elementary teacher in the rural Austrian villages of Trattenbach, Puchberg-am-Schneeberg, and Otterthal. During his time as a schoolteacher, Wittgenstein wrote a pronunciation and spelling dictionary for his use in teaching students; it was published and well received by his colleagues. This would be the only book besides the Tractatus that Wittgenstein published in his lifetime.

Wittgenstein had unrealistic expectations of the rural children he taught, and his teaching methods were intense and exacting - he had little patience with those children who had no aptitude for mathematics. However, he achieved good results with children attuned to his interests and style of teaching, especially boys. His severe disciplinary methods (often involving corporal punishment) &mdash; as well as a general suspicion amongst the villagers that he was somewhat mad &mdash; led to a long series of bitter disagreements with some of his students' parents, and eventually culminated in April 1926 in the collapse of an eleven year old boy whom Wittgenstein had struck on the head. The boy's father attempted to have Wittgenstein arrested, and despite being cleared of misconduct he resigned his position and returned to Vienna, feeling that he had failed as a school teacher.

After abandoning his work as a school teacher, Wittgenstein worked as a gardener's assistant in a monastery near Vienna. He considered becoming a monk, and went so far as to inquire about the requirements for joining an order. However, at the interview he was advised that he would not find in monastic life what he sought.

Two major developments helped to save Wittgenstein from this despairing state. The first was an invitation from his sister Margaret ("Gretl") Stonborough (who was painted by Gustav Klimt in 1905) to work on the design and construction of her new house. He worked with the architect, Paul Engelmann (who had become a close friend of Wittgenstein's during the war), and the two designed a spare modernist house after the style of Adolf Loos (whom they both greatly admired). Wittgenstein found the work intellectually absorbing, and exhausting &mdash; he poured himself into the design in painstaking detail, including even small aspects such as doorknobs and radiators (which had to be exactly positioned to maintain the symmetry of the rooms). As a work of modernist architecture the house evoked some high praise; G. H. von Wright said that it possessed the same "static beauty" as the Tractatus. The effort of totally involving himself in intellectual work once again did much to restore Wittgenstein's spirits.

Secondly, toward the end of his work on the house, Wittgenstein was contacted by Moritz Schlick, one of the leading figures of the newly formed Vienna Circle. The Tractatus had been tremendously influential to the development of the Vienna positivism, and although Schlick never succeeded in drawing Wittgenstein into the discussions of the Vienna Circle itself, he and some of his fellow circle members (especially Friedrich Waismann) met occasionally with Wittgenstein to discuss philosophical topics. Wittgenstein was frequently frustrated by these meetings &mdash; he believed that Schlick and his colleagues had fundamentally misunderstood the Tractatus, and at times would refuse to talk about it at all. (Much of the disagreements concerned the importance of religious life and the mystical; Wittgenstein considered these matters of a sort of wordless faith, whereas the positivists disdained them as useless. In one meeting, Wittgenstein refused to discuss the Tractatus at all, and sat with his back to his guests while he read aloud from the poetry of Rabindranath Tagore.) Nevertheless, the contact with the Vienna Circle stimulated Wittgenstein intellectually and revived his interest in philosophy. He also met with Frank P. Ramsey, a young philosopher of mathematics who travelled several times from Cambridge to Austria to meet with Wittgenstein and the Vienna Circle. In the course of his conversations with the Vienna Circle and with Ramsey, Wittgenstein began to think that there might be some "grave mistakes" in his work as presented in the Tractatus &mdash; marking the beginning of a second career of ground-breaking philosophical work, which would occupy him for the rest of his life.

Returning to Cambridge
In 1929 he decided, at the urging of Ramsey and others, to return to Cambridge. He was met at the train station by a crowd of England's greatest intellectuals, discovering rather to his horror that he was one of the most famed philosophers in the world. In a letter to his wife, Lydia Lopokova, Lord Keynes wrote: "Well, God has arrived. I met him on the 5.15 train."

Despite this fame, he could not initially work at Cambridge, as he did not have a degree, so he applied as an advanced undergraduate. Russell noted that his previous residency was in fact sufficient for a doctoral degree, and urged him to offer the Tractatus as a doctoral thesis, which he did in 1929. It was examined by Russell and Moore; at the end of the thesis defence, Wittgenstein clapped the two examiners on the shoulder and said, "Don't worry, I know you'll never understand it." Moore commented in the examiner's report: "In my opinion this is a work of genius; it is, in any case, up to the standards of a degree from Cambridge." Wittgenstein was appointed as a lecturer and was made a fellow of Trinity College.

Although Wittgenstein was involved in a relationship with Marguerite Respinger (a young Swiss woman he had met as a friend of the family), his plans to marry her were broken off in 1931, and he never married. Most of his romantic attachments were to young men. There is considerable debate over how active Wittgenstein's homosexual life was inspired by W. W. Bartley's claim to have found evidence of not only active homosexuality but in particular several casual liaisons with young men in the Wiener Prater park during his time in Vienna. Bartley published his claims in a biography of Wittgenstein in 1973, claiming to have his information from "confidential reports from... friends" of Wittgenstein, whom he declined to name, and to have discovered two coded notebooks unknown to Wittgenstein's executors that detailed the visits to the Prater. Wittgenstein's estate and other biographers have disputed Bartley's claims and asked him to produce the sources that he claims. What has become clear, in any case, is that Wittgenstein had several long-term homoerotic attachments, including an infatuation with his friend David Pinsent and long-term relationships during his years in Cambridge with Francis Skinner and possibly Ben Richards.

Wittgenstein's political sympathies lay on the left, and while he was opposed to Marxist theory, he described himself as a "communist at heart" and romanticized the life of labourers. In 1934, attracted by Keynes' description of Soviet life in Short View of Russia, he conceived the idea of emigrating to the Soviet Union with Skinner. They took lessons in Russian and in 1935 Wittgenstein travelled to Leningrad and Moscow in an attempt to secure employment. He was offered teaching positions but preferred manual work and returned three weeks later.

From 1936 to 1937, Wittgenstein lived again in Norway, leaving Skinner behind. He worked on the Philosophical Investigations. In the winter of 1936/37, he delivered a series of "confessions" to close friends, most of them about minor infractions like white lies, in an effort to cleanse himself. In 1938 he travelled to Ireland to visit Maurice Drury, a friend who was training as a doctor, and considered such training himself, with the intention of abandoning philosophy for psychiatry. He travelled to Ireland at the invitation of the then Irish Prime Minister, Mr. Eamon de Valera, himself a mathematics teacher. De Valera hoped that Wittgenstein's presence would contribute to an academy for advanced mathematics. Whilst staying in Ireland Wittgenstein resided at the Ashling hotel, now commemorated by a plaque in his honour.

While he was in Ireland, the Anschluss took place. Wittgenstein was now technically a German citizen, and a Jew under the German racial laws. While he found this intolerable, and started to investigate the possibilities of acquiring British or Irish citizenship (with the help of Keynes), which put his siblings Hermine, Helene and Paul (all still residing in Austria) in considerable danger. Wittgenstein's first thought was to travel to Vienna, but he was dissuaded by friends. Had the Wittgensteins been classified as Jews, their fate would have been no different from that of any other Austrian Jews (of approximately 600 in Linz at the end of the 1930s, for example, only 26 survived the war ). Their only hope was to be classified as Mischlinge – officially, Aryan/Jewish mongrels, whose treatment, while harsh, was less brutal than that reserved for Jews. This reclassification was known as a "Befreiung". The successful conclusion of these negotiations required the personal approval of Adolf Hitler. "The figures show how difficult it was to gain a Befreiung. In 1939 there were 2,100 applications for a different racial classification: the Führer allowed only twelve."

Gretl (an American citizen by marriage) started negotiations with the Nazi authorities over the racial status of their grandfather Hermann, claiming that he was the illegitimate son of an "Aryan". Since the Reichsbank was keen to get its hands on the large amounts of foreign currency owned by the Wittgenstein family, this was used as a bargaining tool. Paul, who had escaped to Switzerland and then the United States in July 1938, disagreed with the family's stance. After G. E. Moore's resignation in 1939, Wittgenstein, who was by then considered a philosophical genius, was appointed to the chair in Philosophy at Cambridge. He acquired British citizenship soon afterwards, and in July 1939 he travelled to Vienna to assist Gretl and his other sisters, visiting Berlin for one day to meet with an official of the Reichsbank. After this, he travelled to New York to persuade Paul (whose agreement was required) to back the scheme. The required Befreiung was granted in August 1939. The amount signed over to the Nazis by the Wittgenstein family, a week or so before the outbreak of war, was 1.7 tonnes of gold. At current prices (late 2006), this amount of gold would be worth over $22 million.

After exhausting philosophical work, Wittgenstein would often relax by watching a western (preferring to sit at the very front of the cinema) or reading detective stories. These tastes are in stark contrast to his preferences in music, where he rejected anything after Brahms as a symptom of the decay of society.

By this time, Wittgenstein's view on the foundations of mathematics had changed considerably. Earlier, he had thought that logic could provide a solid foundation, and he had even considered updating Russell and Whitehead's Principia Mathematica. Now he denied that there were any mathematical facts to be discovered and he denied that mathematical statements were "true" in any real sense: they simply expressed the conventional established meanings of certain symbols. He also denied that a contradiction should count as a fatal flaw of a mathematical system. He gave a series of lectures on the foundations of mathematics discussing this and other topics, documented in a book ISBN 0226904261. The book contains lectures by Wittgenstein as well as discussions between Wittgenstein and several attending students including young Alan Turing.

During World War II he left Cambridge and volunteered as a hospital porter in Guy's Hospital in London and as a laboratory assistant in Newcastle upon Tyne's Royal Victoria Infirmary. This was arranged by his friend John Ryle, a brother of the philosopher Gilbert Ryle, who was then working at the hospital. After the war, Wittgenstein returned to teach at Cambridge, but he found teaching an increasing burden: he had never liked the intellectual atmosphere at Cambridge, and in fact encouraged several of his students (including Skinner) to find work outside of academic philosophy. (There are stories, perhaps apocryphal, that if any of his philosophy students expressed an interest in pursuing the subject, he would ban them from attending any more of his classes.)

Final years


Wittgenstein resigned his position at Cambridge in 1947 to concentrate on his writing. He was succeeded as professor by his friend Georg Henrik von Wright. Much of his later work was done on the west coast of Ireland in the rural isolation he preferred. By 1949, when he was diagnosed as having prostate cancer, he had written most of the material that would be published after his death as Philosophische Untersuchungen (Philosophical Investigations), which arguably contains his most important work.

He spent the last two years of his life working in Vienna, the United States, Oxford, and Cambridge. He worked continuously on new material, inspired by the conversations that he had had with his friend and former student Norman Malcolm during a long vacation at the Malcolms' house in the United States. Malcolm had been wrestling with G.E. Moore's common sense response to external world skepticism ("Here is one hand, and here is another; therefore I know at least two external things exist"). Wittgenstein began to work on another series of remarks inspired by his conversations, which he continued to work on until two days before his death, and which were published posthumously as On Certainty.

The only known fragment of music composed by Wittgenstein was premiered in November 2003. It is a piece of music that lasts less than half a minute.

Wittgenstein died from prostate cancer at his doctor's home in Cambridge in 1951. His last words were: "Tell them I've had a wonderful life."

Work
Although many of Wittgenstein's notebooks, papers, and lectures have been published since his death, he published only one philosophical book in his lifetime, the Tractatus Logico-Philosophicus in 1921. Wittgenstein's early work was deeply influenced by Arthur Schopenhauer, and by the new systems of logic put forward by Bertrand Russell and Gottlob Frege. He was also influenced by the ideas of Immanuel Kant, especially in relation to transcendentality. When the Tractatus was published, it was taken up as a major influence by the Vienna Circle positivists. However, Wittgenstein did not consider himself part of that school and alleged that logical positivism involved grave misunderstandings of the Tractatus.

With the completion of the Tractatus, Wittgenstein believed he had solved all the problems of philosophy, and he abandoned his studies, working as a schoolteacher, a gardener at a monastery, and an architect, along with Paul Engelmann, on his sister's new house in Vienna. However, in 1929, he returned to Cambridge, was awarded a Ph.D. for the Tractatus, and took a teaching position there. He renounced or revised much of his earlier work, and his development of a new philosophical method and a new understanding of language culminated in his second magnum opus, the Philosophical Investigations, which was published posthumously.

The Tractatus
In rough order, the first half of the book sets forth the following theses:
 * The world consists of independent atomic facts &mdash; existing states of affairs &mdash; out of which larger facts are built.
 * Language consists of atomic, and then larger-scale propositions that correspond to these facts by sharing the same "logical form".
 * Thought, expressed in language, "pictures" these facts.
 * We can analyse our thoughts and sentences to express ("express" as in show, not say) their true logical form.
 * Those we cannot so analyse cannot be meaningfully discussed.
 * Philosophy consists of no more than this form of analysis: "Wovon man nicht sprechen kann, darüber muß man schweigen" ("Whereof one cannot speak, thereof one must be silent").

Some commentators believe that, although no other type of discourse is, properly speaking, philosophy, Wittgenstein does imply that those things to be passed over "in silence" may be important or useful, according to some of his more cryptic propositions in the last sections of the Tractatus; indeed, that they may be the most important and most useful. He himself wrote about the Tractatus in a letter to his publisher Ficker:

Other commentators point out that the sentences of the Tractatus would not qualify as meaningful according to its own rigid criteria, and that Wittgenstein's method in the book does not follow its own demands regarding the only strictly correct philosophical method. This also is admitted by Wittgenstein, when he writes in proposition 6.54: ‘My propositions are elucidatory in this way: he who understands me finally recognizes them as senseless’. These commentators believe that the book is deeply ironic, and that it demonstrates the ultimate nonsensicality of any sentence attempting to say something metaphysical, something about those fixations of metaphysical philosophers, about those things that must be passed over in silence, and about logic. He attempts to define the limits of logic in understanding the world.

The work also contains several innovations in logic, including a version of the truth table.

Intermediate works
Wittgenstein wrote copiously after his return to Cambridge, and arranged much of his writing into an array of incomplete manuscripts. Some thirty thousand pages existed at the time of his death. Much, but by no means all, of this has been sorted and released in several volumes. During his "middle work" in the 1920s and 1930s, much of his work involved attacks from various angles on the sort of philosophical perfectionism embodied in the Tractatus. Of this work, Wittgenstein published only a single paper, "Remarks on Logical Form," which was submitted to be read for the Aristotelian Society and published in their proceedings. By the time of the conference, however, Wittgenstein had repudiated the essay as worthless, and gave a talk on the concept of infinity instead. Wittgenstein was increasingly frustrated to find that, although he was not yet ready to publish his work, some other philosophers were beginning to publish essays containing inaccurate presentations of his own views based on their conversations with him. As a result, he published a very brief letter to the journal Mind, taking a recent article by R. B. Braithwaite as a case in point, and asked philosophers to hold off writing about his views until he was himself ready to publish them. Although unpublished, the Blue Book, a set of notes dictated to his class at Cambridge in 1933 – 1934 contains seeds of Wittgenstein's later thoughts on language (later developed in the Investigations), and is widely read today as a turning point in his philosophy of language.

The Philosophical Investigations
Although the Tractatus is still considered a major work, Wittgenstein is mostly studied today for the Philosophical Investigations (Philosophische Untersuchungen). In 1953, two years after Wittgenstein's death, the long-awaited book was published in two parts. Most of the 693 numbered paragraphs in Part I were ready for printing in 1946, but Wittgenstein withdrew the manuscript from the publisher. The shorter Part II was added by the editors, G.E.M. Anscombe and Rush Rhees. (Had Wittgenstein lived to complete the book himself, some of the remarks in Part II would likely have been incorporated into Part I, and the book would no longer have this bifurcated structure.)

It is notoriously difficult to find consensus among interpreters of Wittgenstein's work, and this is particularly true in the case of the Investigations. Very briefly, Wittgenstein asks the reader to think of language and its uses as a multiplicity of language-games within which the parts of language function, and have meaning, and this understanding will help to resolve the problems of philosophy. This view of language represents what many consider a break from the Wittgenstein of the Tractatus and, therefore, 'meaning as representation'. In the carrying out of such an investigation, one of the most radical characteristics of the "later" Wittgenstein comes to light. The "conventional" view of philosophy's "task", perhaps coming to a head in Bertrand Russell, is that the philosopher's task is to solve the seemingly intractable problems of philosophy using logical analysis (for example, the problem of "free will", the relationship between "mind" and "matter", what is "the good" or "the beautiful" and so on). However, Wittgenstein argues that these "problems" are, in fact, "bewitchments" that arise from the philosophers' misuse of language.

On Wittgenstein's account, language is inextricably woven into the fabric of life, and as part of that fabric it works relatively unproblematically. Philosophical problems arise, on this account, when language is forced from its proper home and into a metaphysical environment, where all the familiar and necessary landmarks and contextual clues are absent. Removed, perhaps, for what appear to be sound philosophical reasons, but which leads, for Wittgenstein, to the source of the problem. Wittgenstein describes this metaphysical environment as like being on frictionless ice ; where the conditions are apparently perfect for a philosophically and logically perfect language (the language of the Tractatus), where all philosophical problems can be solved without the confusing and muddying effects of everyday contexts; but where, just because of the lack of friction, language can in fact do no actual work at all. There is much talk in the Investigations, then, of “idle wheels” and language being “on holiday” or a mere "ornament", all of which are used to express the idea of what is lacking in philosophical contexts. To resolve the problems encountered there, Wittgenstein argues that philosophers must leave the frictionless ice and return to the “rough ground” of ordinary language in use; that is, philosophers must “bring words back from their metaphysical to their everyday use.”

In this regard, one can see affinities between Wittgenstein and Kant. In the Critique of Pure Reason, Kant argues that when concepts grounded in experience are applied outside of the range of possible experience, the result is contradictions and confusion. Thus the second part of the Critique consists of refutations, typically by reductio ad absurdum, of logical proofs of the existence of god and the existence of souls, and deconstructions of strong notions of infinity and necessity. In this way, Wittgenstein's objections to applying words outside the contexts in which they have an established meaning mirror Kant's objections to the non-empirical use of empirical reason.

Returning to the rough ground of ordinary uses of words is, however, easier said than done. Philosophical problems have the character of depth and run as deep as the forms of language and thought that set philosophers on the road to confusion. Wittgenstein therefore speaks of “illusions”, "bewitchment" and “conjuring tricks” performed on our thinking by our forms of language, and tries to break their spell by attending to differences between superficially similar aspects of language which he feels leads to this type of confusion. For much of the Investigations, then, Wittgenstein tries to show how philosophers are led away from the ordinary world of language in use by misleading aspects of language itself. He does this by looking in turn at the role language plays in the development of various philosophical problems, from some general problems involving language itself, then at the notions of rules and rule following, and then on to some more specific problems in philosophy of mind. Throughout these investigations, the style of writing is conversational with Wittgenstein in turn taking the role of the puzzled philosopher (on either or both sides of traditional philosophical debates), and that of the guide attempting to show the puzzled philosopher the way back: the “way out of the fly bottle.”

Much of the Investigations, then, consists of examples of how philosophical confusion is generated and how, by a close examination of the actual workings of everyday language, the first false steps towards philosophical puzzlement can be avoided. By avoiding these first false steps, philosophical problems themselves simply no longer arise and are therefore dissolved rather than solved. As Wittgenstein puts it; "the clarity we are aiming at is indeed complete clarity. But this simply means that the philosophical problems should completely disappear."

Later work

 * On Certainty &mdash; A collection of aphorisms discussing the relation between knowledge and certainty, extremely influential in the philosophy of action.
 * Remarks on Colour &mdash; Remarks on Goethe's Theory of Colours.
 * Culture and Value &mdash; A collection of personal remarks about various cultural issues, such as religion and music, as well as critique of Søren Kierkegaard's philosophy.
 * Zettel, another collection of Wittgenstein's thoughts in fragmentary/"diary entry" format as with On Certainty and Culture and Value.

Important publications

 * Logisch-Philosophische Abhandlung, Annalen der Naturphilosophie, 14 (1921)
 * Tractatus Logico-Philosophicus, translated by C.K. Ogden (1922)
 * Philosophische Untersuchungen (1953)
 * Philosophical Investigations, translated by G.E.M. Anscombe (1953)
 * Bemerkungen über die Grundlagen der Mathematik, ed. by G.H. von Wright, R. Rhees, and G.E.M. Anscombe (1956) (a selection from his writings on the philosophy of logic and mathematics between 1937 and 1944)
 * Remarks on the Foundations of Mathematics, translated by G.E.M. Anscombe, rev. ed. (1978)
 * The Blue and Brown Books (1958) (Notes dictated in English to Cambridge students in 1933-35)
 * Philosophische Bemerkungen, ed. by Rush Rhees (1964)
 * Philosophical Remarks (1975)
 * Bemerkungen über die Farben, ed. by G.E.M. Anscombe (1977)
 * Remarks on Colour ISBN 0-520-03727-8

Works online

 * Review of P. Coffey's Science of Logic (1913): a polemical book review, written in 1912 for the March 1913 issue of the The Cambridge Review when Wittgenstein was an undergraduate studying with Russell. The review is the earliest public record of Wittgenstein's philosophical views.
 * Tractatus Logico-Philosophicus (1922/1923), German text and Ogden-Ramsey translation
 * Cambridge (1932-3) lecture notes
 * Lecture on Ethics
 * (A Few) Remarks
 * (A Few) Remarks

Influence
Both his early and later work have been major influences in the development of analytic philosophy. Former students and colleagues include Gilbert Ryle, Friedrich Waismann, Norman Malcolm, G. E. M. Anscombe, Rush Rhees, Georg Henrik von Wright and Peter Geach.

Contemporary philosophers heavily influenced by him include Michael Dummett, Donald Davidson, Peter Hacker, John R. Searle, Saul Kripke, John McDowell, Hilary Putnam, Anthony Quinton, Peter Strawson, Paul Horwich, Colin McGinn, Daniel Dennett, Richard Rorty, Stanley Cavell, Cora Diamond, James F. Conant, and Jean-François Lyotard.

With others, Conant, Diamond and Cavell have been associated with an interpretation of Wittgenstein sometimes known as the New Wittgenstein.

However, it cannot really be said that Wittgenstein founded a 'school' in any normal sense. The views of most of the above are generally contradictory. Indeed there are strong strains in his writings from the Tractatus onwards which would probably have regarded any such enterprise as fundamentally misguided.

Wittgenstein has also had a significant influence on psychology and psychotherapy. Most significantly, social therapy has made use of Wittgenstein's language games as a tool for emotional growth. Psychologists and psychotherapist inspired by Wittgenstein's work include Fred Newman, Lois Holzman, Brian J. Mistler, and John Morss.

Wittgenstein's influence has extended beyond what is normally considered philosophy and may be found in various areas of the arts. A recent example is Steve Reich's 'You are' one of the movements of which is taken from 'On Certainty': 'Explanations come to an end somewhere'. Since Reich was at one time a philosophy student, publishing a thesis on Wittgenstein, this may be considered a legitimate use. Additionally, interdisciplinary research on language and information theory by various members of the Domon Group have drawn heavily on Wittgenstein's Tractatus as well as unpublished works.

Works about Wittgenstein

 * The Jew of Linz, by Kimberley Cornish, puts forward the controversial thesis that Hitler's antisemitism arose from his dislike of Wittgenstein, and that Wittgenstein was a Soviet agent who recruited the "Cambridge Five".
 * E. L. Doctorow imagines a rivalry between Wittgenstein and Einstein in sections of his novel City of God, narrated as Wittgenstein.
 * Avant-garde filmmaker Derek Jarman directed Wittgenstein (1993). The script and the original treatment by Terry Eagleton have been published as a book by the British Film Institute.
 * For an extensive account of Wittgenstein's design of the house for his sister in Vienna see the book Ludwig Wittgenstein, Architect by Paul Wijdeveld, MIT Press, 1994. For a discussion of the connection between Wittgenstein's architecture and his philosophy see Kari Jormakka, "The Fifth Wittgenstein", Datutop 24, 2004.
 * The life of Wittgenstein has been recreated in a novel, The World as I Found It by Bruce Duffy (1997).
 * The famous non-meeting between Wittgenstein and Karl Popper has been described in the book Wittgenstein's Poker. The Story of a Ten-Minute Argument Between Two Great Philosophers, by David Edmonds and John Eidenow (2002).