Tractatus Logico-Philosophicus

The Tractatus Logico-Philosophicus (Logical Philosophical Treatise or Treatise on Logic and Philosophy) is the only full-length philosophical book by the Austrian philosopher Ludwig Wittgenstein that was published during his lifetime. The goal of the work is to identify the relationship between language and reality and to define the limits of science. He famously summarized the book in the following way: "What can be said at all can be said clearly; and what we cannot talk about we must pass over in silence."