I have tried to make this book an argument, not a catalogue of dogmas. Its ideal reader will find himself constantly asking questions, for which he will insist on finding his own answers. To avoid wasting his time, I have made the fullest use of authentic illustrations from newspapers, books, and other contemporary sources. One of the wisest things ever said about our subject is that "Logic, like whiskey, loses its beneficial effect when taken in too large doses." While bearing this constantly in mind, I have also aimed at a high level of accuracy and the inclusion of nothing that would have to be unlearnt at a more advanced level of study. This book could never have been written without the help of the students to whom I have lectured on logic and scientific method. My chief obligations are to them. Logic ought to be easy, interesting, and enjoyable. This book will have been successful if it helps some readers to find it so.—Prof. Max Black