Initially proposed as rivals of classical logic, alternative logics have become increasingly important in areas such as computer science and arti ficial intelligence. Fuzzy logic, in particular, has motivated major technological developments in recent years. Susan Haack's "Deviant Logic" provided an extended examination of the philosophical consequences of alternative logics. In this volume, Haack includes the complete text of "Deviant Logic", as well as five additional papers that expand and update it. Two of these essays critique fuzzy logic, while three augment "Deviant Logic"'s treatment of deduction and logical truth. Haack also provides an extensive new foreword, brief introductions to the new essays, and an updated bibliography of current work in these areas.