This book provides an invaluable overview of the reach of logic. It provides reference to some of the most important, well-established results in logic, while at the same time offering insight into the latest research issues in the area. It also has a balance of theory and practice, containing essays in the areas of Modal Logic, Intuitionistic Logic, Logic and Language, Non-monotonic Logic and Logic Programming, Temporal Logic, Logic and Learning, Combination of Logics, Practical Reasoning, Logic and Artificial Intelligence, Abduction, Theorem Proving, and Goal-Directed Reasoning. It will be invaluable reading for researchers and graduate students in Logic and Computer Science, and a fabulous source of inspiration for research students in search of a topic for a PhD in logic and theoretical computer science.