Quantum mechanics is said to be the most successful physical theory ever. It is, in fact, unique in its success when applied to concrete physical problems. On the other hand, however, it raises profound conceptual problems which are equally unprecedented. Quantum logic, the topic of this volume, can be described as an attempt to cast light on the puzzle of quantum mechanics from the point of view of logic. Since its inception in the famous 1936 paper by Birkhoff and von Neumann entitled "The logic of quantum mechanics", quantum logic has undergone an enormous development. Various schools of thought and approaches have emerged and there are a variety of technical results. The chapters of this volume constitute a comprehensive presentation of the main schools, approaches and results in the field of quantum logic. . Authored by eminent scholars in the field . Material presented is of recent origin representing the frontier of the subject. . Provides the most comprehensive and varied discussion of Quantum Mechanics available.