Ludwig Wittgenstein's Tractatus Logico-Philosophicus is an unquestioned philosophical masterpiece. It is a work of extreme compression. Within a compass of twenty thousand words, and in cryptic and elliptical sentences, Wittgenstein writes of the nature of the universe, the essence of language, the foundations of logic and mathematics, theories of probability, philosophical method, and the work of Bertrand Russell and Gottlob Frege. Finding it difficult, if not distasteful, to force philosophical thoughts and insights into a linear deductive order, Wittgenstein also makes scattered comments about the philosophy of science, ethics, religion, and mysticism. In A Companion to Wittgenstein's "Tractatus," the distinguished philosopher Max Black provides students with a collocation of scattered passages and a close commentary on the text. This brilliant book allows readers to fully apprehend the value of Tractatus Logico-Philosophicus as both a unique text and as the foundation for much subsequent work in philosophy.