'The material presented in this edition is of the first importance to Wittgenstein scholarship. It helps us narrow in on early but richly developed steps in Wittgenstein's thinking on issues to do with meaning and understanding, the notion of 'grammar', rule following, notions of sense and nonsense, and the foundations of logic and mathematics … The editorial approach laid out in the rich introduction and demonstrated in the main sections of the edition seems to me to be just right, striking a balance between completeness and faithfulness, on the one hand, and readability on the other … this edition helps get us closer to hearing more fully and more directly what Wittgenstein said in his lectures from this period.' Jeff Johnson, St Catherine University, Minnesota