First published in 1921, Ludwig Wittgenstein's Tractatus Logico-Philosophicus is one of the most influential—and one of the most obscure—philosophical works of the twentieth century. Duncan Richter’s new translation of and commentary on the Tractatus help the reader understand the text and directs the reader to relevant secondary literature. To avoid imposing any particular interpretation on the text, this translation is as literal as possible while honoring Wittgenstein's wishes about how his words should be rendered in English. For similar reasons, Richter more often quotes than paraphrases the selected secondary sources, which represent a variety of opinions on what Wittgenstein meant. This book also includes an introduction by Richter and a bibliography. Like the Tractatus itself, this is not a textbook but a version of the text designed for those who want to read and understand it for themselves.