Philosophy › The 20th century › Ludwig Wittgenstein
Tractatus Logico-Philosophicus
1921· Book or text· Knowledge, logic & science
Well documentedSolid records, texts or physical evidence.
Wittgenstein's short book of numbered remarks claiming that language pictures facts, and that what cannot be said must be passed over in silence.
See it on the Philosophy map →The idea
Idea: a meaningful sentence is a logical picture of a possible fact. It opens 'The world is everything that is the case' and ends 'Whereof one cannot speak, thereof one must be silent.' Ethics, beauty and the meaning of life cannot be stated, only shown. Wittgenstein thought it had solved philosophy's problems and quit the field. Main objection: by its own rules its own sentences are nonsense, which he admitted, calling them a ladder to throw away once climbed.
Why it matters
It inspired logical positivism and set the terms for how language, logic and the world relate; rejecting it shaped Wittgenstein's later philosophy.
Where it comes from
Drafted in wartime notebooks and finished in 1918, it was published in German in 1921 and in English in 1922, with an introduction by Russell.
Still debated
Whether it holds that deep truths can only be 'shown', or that there is nothing at all beyond what can be said, divides its readers.
Connections (3)
▸Ludwig Wittgenstein wrote Tractatus Logico-PhilosophicusWell documented
The connection
Wittgenstein worked out the book in notebooks while serving in the Austro-Hungarian army in World War I, including at the front. He believed it had solved the problems of philosophy in principle, and after publishing it he left philosophy for years to teach in village schools.
When and how
Written 1914–18 and finished in summer 1918; he was captured in Italy in November 1918 with the manuscript in his rucksack. Published in German in 1921, English in 1922.
How we know
His surviving wartime notebooks (published 1961) show the drafts; letters to Russell from the prison camp discuss the manuscript.
Debates and open questions
He later admitted 'grave mistakes' in the book, and scholars debate what, if anything, he thought survived into his later philosophy.
▸Tractatus Logico-Philosophicus inspired Logical positivism and the Vienna CircleWell documented
The connection
The Vienna Circle read the Tractatus line by line and took from it two ideas: logical truths are tautologies, true by form alone, and meaningful sentences picture facts. They turned this into the verification principle: a statement's meaning is its method of verification. They largely ignored its mystical closing remarks.
When and how
Schlick's Circle studied the book in Vienna in 1926–27; Wittgenstein met Schlick and Friedrich Waismann from 1927, sometimes reading poetry aloud instead of discussing philosophy.
How we know
Their 1929 manifesto names Wittgenstein as a leading figure, and Waismann's notes record conversations with him from 1929 to 1932.
Debates and open questions
Wittgenstein felt misread: for him the unsayable mattered most, while the Circle dismissed it as nonsense. Whether he ever held a verification principle is debated.
▸Philosophical Investigations and language games rejected the picture theory of Tractatus Logico-PhilosophicusWell documented
The connection
The Tractatus said sentences mirror facts, like pictures. The Investigations rejects this: language has countless uses, such as giving orders, telling jokes or praying, and few work by picturing. Wittgenstein even wanted the two books printed together, so readers could see the new thinking against the old.
When and how
In the 1945 preface Wittgenstein wrote that he had 'been forced to recognize grave mistakes' in his first book; section 23 lists many language games.
How we know
The preface and many sections directly criticize the Tractatus, including its 'simple objects' (sections 46–48).
Debates and open questions
Scholars debate how sharp the break was: 'New Wittgensteinians' see continuity, both books aiming to cure philosophical confusion rather than offer theories.