Wittgenstein's Whewell's Court Lectures contains previously unpublished notes from lectures given by Ludwig Wittgenstein between 1938 and 1941. The volume offers new insight into the development of Wittgenstein's thought and includes some of the finest examples of Wittgenstein's lectures in regard to both content and reliability.-Many notes in this text refer to lectures from which no other detailed notes survive, offering new contexts to Wittgenstein's examples and metaphors, and providing a more thorough and systematic treatment of many topics -Each set of notes is accompanied by an editorial introduction, a physical description and dating of the notes, and a summary of their relation to Wittgenstein's Nachlass -Offers new insight into the development of Wittgenstein's ideas, in particular his ideas about certainty and concept-formation -The lectures include more than 70 illustrations of blackboard drawings, which underline the importance of visual thought in Wittgenstein's approach to philosophy -Challenges the dating of some already published lecture notes, including the Lectures on Freedom of the Will and the Lectures on Religious Belief.