This revised and partially restructured second edition of what was a pioneering text combines the best of the old with extensive new material to bring it up to date with contemporary affairs. In this second, revised, edition we have focused upon: -Clear explanations of essential logical concepts and distinctions -Comprehensive Theory of Knowledge syllabus coverage -A controlled vocabulary with glossaries attached to each chapter -Relevant, challenging, up-to-date examples -Detailed case studies illustrating important points -Exercises with answers -Treatment of the material beyond the level of immediate, easy scepticism -Ideas for discussion, presentations and essay writing -Index of concepts -You will never be short of relevant material on any part of a two-year course -Your course will be one with substance, which will actually stretch the students, generate insight, help them develop their critical faculties, and prepare them with the necessary logical and -The relevance of your course, both to contemporary issues and the students' own education will be evident to them.