this is a rewarding book. It is a must-read for everyone interested in the philosophy of paraconsistent logic.

Bartosz Wieckowski, Studia Logica

This wide-ranging book is divided into four Parts: Truth, Negation, Rationality and Logic. Priest's discussion of these topics is centered around their bearing on his doctrine of dialetheism, the view that some contradictions are true; but the discussions are of great interest independent of dialetheism. The quality of the discussion is generally very high, and the book is a must-read for anyone interested in the central questions of the philosophy of logic. . . . I found this a thoroughly stimulating book. I recommend it with great enthusiasm.

Hartry Field, Notre Dame Philosophical Reviews