Paraconsistent logic is a branch of logic which concerns the logical structure of inconsistent situations. Though the subject has roots which spread back through the history of philosophy, in its modern form it is barely thirty years old. It is, therefore, still in a young and rapidly developing state. Orthodox logical theory presupposes that there are no inconsistent situations in any important sense. This is a view which also underpins much traditional metaphysics and epistemology. Paraconsistency rejects this view and, therefore, poses a radical challenge to orthodox logic and much orthodox philosophy. It is, therefore, potentially a development of singular importance. This book brings together a collection of essays by most of the leading workers in the field of paraconsistency. All of the essays are previously unpublished and many are undoubtedly of first importance for the subject. However, since the subject is a novel and, therefore, an unfamiliar one, the authors have included substantial introductory essays which explain the current state of the discipline, explore its historical roots and philosophical implications and survey the prospects for future research in the area. Most of the published work in paraconsistency is written for the initiate, concentrates on a small aspect of it, and is spread out over numerous journals. This book therefore provides fort he first time a focal point for research on the subject which will be invaluable to both the novice and the initiate alike.