Tractatus Logico-Philosophicus is the only book-length philosophical work published by the Austrian philosopher Ludwig Wittgenstein during his lifetime. It is an ambitious project to identify the relationship between language and reality and to define the limits of science. It is recognized as one of the most important philosophical works of the twentieth century. G. E. Moore originally suggested the work's Latin title as homage to Tractatus Theologico-Politicus by Baruch Spinoza.

Wittgenstein wrote Tractatuswhile he was a soldier and prisoner of war during World War I. It was first published in German in 1921 as Logisch-Philosophische Abhandlung. The Tractatus was influential chiefly amongst the logical positivists of the Vienna Circle, such as Rudolf Carnap and Friedrich Waismann. Bertrand Russell's article "The Philosophy of Logical Atomism" is presented as a working out of ideas that he had learnt from Wittgenstein.

Tractatus employs a notoriously austere and succinct literary style. The work contains almost no arguments as such, but rather declarative statements which are meant to be self-evident. The statements are hierarchically numbered, with seven basic propositions at the primary level (numbered 1–7), with each sub-level being a comment on or elaboration of the statement at the next higher level (e.g., 1, 1.1, 1.11, 1.12).

Wittgenstein's later works, notably the posthumously published Philosophical Investigations, retracted many of the ideas in Tractatus.

Main theses

There are seven main propositions in the text. These are:

1. The world is everything that is the case.
2. What is the case (a fact) is the existence of states of affairs.
3. A logical picture of facts is a thought.
4. A thought is a proposition with sense.
5. A proposition is a truth-function of elementary propositions.
6. The general form of a proposition is the general form of a truth function, which is: [\bar p,\bar\xi, N(\bar\xi)].
7. Where (or of what) one cannot speak, one must pass over in silence.

Propositions 1.*-3.*

The central thesis of 1., 2., 3. and their subsidiary propositions is Wittgenstein’s picture theory of language. This can be summed up as follows:

• The world consists of a totality of interconnected atomic facts, and propositions make "pictures" of the world.
• In order for a picture to represent a certain fact it must in some way possess the same logical structure as the fact. The picture is a standard of reality. In this way, linguistic expression can be seen as a form of geometric projection, where language is the changing form of projection but the logical structure of the expression is the unchanging geometric relationships.
• We cannot say with language what is common in the structures, rather it must be shown, because any language we use will also rely on this relationship, and so we cannot step out of our language with language.

Propositions 4.*-5.*

The 4s are significant as they contain some of Wittgenstein's most explicit statements concerning the nature of philosophy and the distinction between what can be said and what can only be shown. It is here, for instance, that he first distinguishes between material and grammatical propositions, noting:

A philosophical treatise attempts to say something where nothing can properly be said. It is predicated upon the idea that philosophy should be pursued in a way analogous to the natural sciences; that philosophers are looking to construct true theories. This sense of philosophy does not coincide with Wittgenstein's conception of philosophy.

Wittgenstein is to be credited with the invention of truth tables (4.31) and truth conditions (4.431) which now constitute the standard semantic analysis of first-order sentential logic. The philosophical significance of such a method for Wittgenstein was that it alleviated a confusion, namely the idea that logical inferences are justified by rules. If an argument form is valid, the conjunction of the premises will be logically equivalent to the conclusion and this can be clearly seen in a truth table; it is displayed. The concept of tautology is thus central to Wittgenstein's Tractarian account of logical consequence, which is strictly deductive.

Propositions 6.*

In the beginning of 6. Wittgenstein postulates the essential form of all sentences. He uses the notation [\bar p,\bar\xi, N(\bar\xi)], where

• \bar p stands for all atomic propositions,
• \bar\xi stands for any subset of propositions, and
• N(\bar\xi) stands for the negation of all propositions making up \bar\xi.

What proposition 6. really says is that any logical sentence can be derived from a series of nand operations on the totality of atomic propositions. This is in fact a well-known logical theorem produced by Henry M. Sheffer, of which Wittgenstein makes use. Sheffer's result was, however, restricted to the propositional calculus, and so, of limited significance. Wittgenstein's N-operator is however an infinitary analogue of the Sheffer stroke, which applied to a set of propositions produces a proposition that is equivalent to the denial of every member of that set. Wittgenstein shows that this operator can cope with the whole of predicate logic with identity - defining the quantifiers at 5.52, and showing how identity would then be handled at 5.53-5.532.

The subsidiaries of 6. contain more philosophical reflections on logic, connecting to ideas of knowledge, thought, and the a priori and transcendental. The final passages argue that logic and mathematics express only tautologies and are transcendental, i.e. they lie outside of the metaphysical subject’s world. In turn, a logically "ideal" language cannot supply meaning, it can only reflect the world, and so, sentences in a logical language cannot remain meaningful if they are not merely reflections of the facts.

In the final pages Wittgenstein veers towards what might be seen as religious considerations. This is founded on the gap between propositions 6.5 and 6.4. A logical positivist might accept the propositions of Tractatus before 6.4. But 6.51 and the succeeding propositions argue that ethics is also transcendental, and thus we cannot examine it with language, as it is a form of aesthetics and cannot be expressed. He begins talking of the will, life after death, and God. In his examination of these issues he argues that all discussion of them is a misuse of logic. Specifically, since logical language can only reflect the world, any discussion of the mystical, that which lies outside of the metaphysical subject's world, is meaningless. This suggests that many of the traditional domains of philosophy, e.g. ethics and metaphysics, cannot in fact be discussed meaningfully. Any attempt to discuss them immediately loses all sense. This also suggests that his own project of trying to explain language is impossible for exactly these reasons. He suggests that the project of philosophy must ultimately be abandoned for those logical practices which attempt to reflect the world, not what is outside of it. The natural sciences are just such a practice, he suggests.

At the very end of the text he borrows an analogy from Arthur Schopenhauer, and compares the book to a ladder that must be thrown away after one has climbed it. In doing so he suggests that through the philosophy of the book one must come to see the utter meaninglessness of philosophy.

Proposition 7

As the last line in the book, proposition 7 has no supplementary propositions. It ends the book with a rather elegant and stirring proposition: "What we cannot speak of we must pass over in silence." (In German: "Wovon man nicht sprechen kann, darüber muß man schweigen.") The Ogden translation renders it: "Whereof one cannot speak, thereof one must be silent."

Both the first and the final proposition have acquired something of a proverbial quality in German, employed as aphorisms independently of discussion of Wittgenstein.

Reception and effects

Wittgenstein concluded that with the Tractatus he had resolved all philosophical problems, and upon its publication he retired to become a schoolteacher in Austria.

Meanwhile, the book was translated into English by C. K. Ogden with help from the Cambridge mathematician and philosopher Frank P. Ramsey, then still in his teens. Ramsey later visited Wittgenstein in Austria. Translation issues make the concepts hard to pinpoint, especially given Wittgenstein's usage of terms and difficulty in translating ideas into words.

The Tractatus caught the attention of the philosophers of the Vienna Circle (1921-1933), especially Rudolf Carnap and Moritz Schlick. The group spent many months working through the text out loud, line by line. Schlick eventually convinced Wittgenstein to meet with members of the circle to discuss the Tractatus when he returned to Vienna (he was then working as an architect). Although the Vienna Circle's logical positivists appreciated the Tractatus, they argued that the last few passages, including Proposition 7, are confused. Carnap hailed the book as containing important insights, but encouraged people to ignore the concluding sentences. Wittgenstein responded to Schlick commenting, "...I cannot imagine that Carnap should have so completely misunderstood the last sentences of the book and hence the fundamental conception of the entire book."

A more recent interpretation comes from the New Wittgenstein family of interpretations (2000-). This so-called "resolute reading" is controversial and much debated. The main contention of such readings is that Wittgenstein in the Tractatus does not provide a theoretical account of language that relegates ethics and philosophy to a mystical realm of the unsayable. Rather, the book has a therapeutical aim. By working through the propositions of the book the reader comes to realize that language is perfectly suited to all his needs, and that philosophy rests on a confused relation to the logic of our language. The confusion that the Tractatus seeks to dispel is not a confused theory, such that a correct theory would be a proper way to clear the confusion, rather the need of any such theory is confused. The method of the Tractatus is to make the reader aware of the logic of our language as he is already familiar with it, and the effect of thereby dispelling the need for a theoretical account of the logic of our language spreads to all other areas of philosophy. Thereby the confusion involved in putting forward e.g. ethical and metaphysical theories is cleared in the same coup. James F. Conant argues that Wittgenstein's method in the Tractatus mirrors the method of Kierkegaard's Climacus works. In the appendix of Concluding Unscientific Postscript, Kierkegaard writes:

[The reader] can understand that the understanding is a revocation--the understanding with him as the sole reader is indeed the revocation of the book. He can understand that to write a book and to revoke it is not the same as refraining from writing it, that to write a book that does not demand to be important for anyone is still not the same as letting it be unwritten.[5163]

Wittgenstein would not meet the Vienna Circle proper, but only a few of its members, including Schlick, Carnap, and Waissman. Often, though, he refused to discuss philosophy, and would insist on giving the meetings over to reciting the poetry of Rabindranath Tagore with his chair turned to the wall. He largely broke off formal relations even with these members of the circle after coming to believe Carnap had used some of his ideas without permission.

Carnap and a number of other members of the Vienna Circle seem according to modern research to have misinterpreted Wittgenstein's elementary statements as atomic reports of sensory experience, whence Carnap's attempt at a reduction of concepts to sense experience in his book The Logical Structure of the World (1928). This effort, in which the American philosopher Nelson Goodman participated in his own book The Structure of Appearance (1951), strangely prefigures computer reconstruction of analogue experience (where Carnap's examples of color patches and tones prefigure pixels and sound files). Wittgenstein, at Cambridge (1929-1949), had arrived at the necessity for a formal language, which he describes only schematically, by way of theory, critically in his deduction of the necessity of ontological structure (if the world had no structure, then every proposition's meaning would depend on the truth of another proposition).

The Tractatus was the theme of a 1992 film by the Hungarian filmmaker Peter Forgacs. The 32-minute production named Wittgenstein Tractatus features citations from the Tractatus and other works by Wittgenstein. Another film named The Oxford Murders (2008) also cited the seventh proposition and also described a part of Wittgenstein's life when he was at the war-front.

Editions

The Tractatus is the English translation of

• Logisch-Philosophische Abhandlung, Wilhelm Ostwald (ed.), Annalen der Naturphilosophie, 14 (1921)

A notable German Edition of the works of Wittgenstein is:

• Werkausgabe (Vol. 1 includes the Tractatus). Frankfurt am Main: Suhrkamp Verlag.

Both English translations of the Tractatus include an introduction by Bertrand Russell. Wittgenstein revised the Ogden translation.

• C. K. Ogden (1922), prepared with assistance from G. E. Moore, F. P. Ramsey, and Wittgenstein. Routledge & Kegan Paul, parallel edition including the German text on the facing page to the English text: 1981 printing: ISBN 0-415-05186-X, 1999 Dover reprint: ISBN 0-486-40445-5
• David Pears and Brian McGuinness (1961), Routledge, hardcover: ISBN 0-7100-3004-5, 1974 paperback: ISBN 0-415-02825-6, 2001 hardcover: ISBN 0-415-25562-7, 2001 paperback: ISBN 0-415-25408-6

A manuscript version of the Tractatus, dubbed and published as the Prototractatus, was discovered in 1965 by Georg Henrik von Wright.

See also

• Tractatus Logico-Philosophicus
• Ludwig Wittgenstein
• Philosophical Investigations

Notes

1. TLP 4.113
2. Grayling, A.C. Wittgenstein: A Very Short Introduction, Oxford
3. Conant, James F. "Putting Two and Two Together: Kierkegaard, Wittgenstein and the Point of View for Their Works as Authors", in Philosophy and the Grammar of Religious Belief (1995), ed. Timothy Tessin and Marion von der Ruhr, St. Martins Press, ISBN 0-31212394-9
4. Crary, Alice M. and Rupert Read (eds.). The New Wittgenstein, Routledge, 2000.
5. Jaakko Hintikka (2000) On Wittgenstein, ISBN 0-534-57594-3 p. 55 cites Wittgenstein's accusation of Carnap upon receiving a 1932 preprint from Carnap.

External links

English versions online

• http://www.kfs.org/~jonathan/witt/tlph.html (Ogden translation)
• http://www.gutenberg.org/etext/5740 (Pears & McGuinness translation)
• http://filepedia.org/node/15 (Full Text. PDF version)
• PhiloSURFical Research software tool aimed at facilitating the study of the Tractatus. The text is available in German and in both English translations (Ogden & Pears-McGuinness)
• Graphical tabs-centered version of the Tractatus Logico-Philosophicus (based on the Project Gutenberg edition)

German version online

• http://www.geocities.jp/red_mad_hatter/Tractatus/jonathan/D.html
• http://www.tractatus.hochholzer.info
• http://www.kfs.org/~jonathan/witt/tlph.html (Ogden translation (incomplete))
• PhiloSURFical