What is the relationship between language and reality? That’s the question that Ludwig Wittgenstein attempted to answer in the seven propositions of his Tractatus Logico-Philosophicus. Begun while Wittgenstein was on the front lines of WWI and completed when he was a POW in an Italian prison camp, the Tractatus is the only book-length philosophical work published during Wittgenstein’s lifetime. The book had a major impact on the development of logical positivism, and Bertrand Russell’s Philosophy of Logical Atomism is a working out of Wittgenstein’s propositions. The book contains seven main propositions, followed by a varying number of sub-propositions. The statements are intended to be self-evident; they are given no logical support or explanation. One of Wittgenstein’s overarching goals in the Tractatus is to show that much of philosophy is meaningless. He drives this home with the seventh proposition, which states, “Whereof one cannot speak, thereof one must be silent.” This volume contains C. K. Ogden’s English translation of Tractatus Logico-Philosophicus.