Neil Tennant presents an original logical system with unusual philosophical, proof-theoretic, metalogical, computational, and revision-theoretic virtues. Core Logic is the first system that ensures both relevance and adequacy for the formalization of all mathematical and scientific reasoning. Although the author's approach is purely logical and philosophical, rather than mathematical, it seems likely that the book would be extremely interesting to mathematicians specializing in logic and the foundations of mathematics. Due to the author's clear and approachable style this book may be interesting to a large circle of logicians, mathematicians and philosophers. Students with a basic understanding of classical, intuitionistic and relevant logic principles will find this book an invaluable introduction to an area of central importance in logic, philosophy, computer science and, generally, methodology and philosophy of science.