Michael Potter unequivocally demonstrates the philosophical and historical importance of the Notes for the first time. By teasing out the meaning of key passages, he shows how many of the most important insights in the Tractatus they contain. He discusses in detail how Wittgenstein arrived at these insights by thinking through ideas he obtained from Russell and Frege. And he uses a challenging blend of biography and philosophy to illuminate the methods Wittgenstein used in his work.