Tractatus Logico-Philosophicus

The only philosophical book Wittgenstein published in his lifetime, written largely during his service in the First World War and published in German in 1921 and in English, with an introduction by Bertrand Russell, in 1922. Its numbered remarks hang from seven main propositions. The world is the totality of facts, not of things. Propositions are pictures of possible states of affairs, sharing a logical form with what they depict; complex propositions are truth-functions of elementary ones, and the propositions of logic are tautologies that say nothing. What can be said at all can be said clearly, but logical form itself cannot be said, only shown. Ethics, aesthetics, the meaning of life and the metaphysical subject lie outside what can be said. In the closing remarks Wittgenstein calls his own propositions nonsense, a ladder to be thrown away once climbed, and ends by enjoining silence about what cannot be spoken of.

It shaped logical positivism and analytic philosophy of language, and its final pages pose in sharp form the question of what philosophy can say about value and meaning.