The Mystery of Reason investigates the enterprise of human thought searching for God. People have always found stepping-stones to God's existence carved in the world and in the human condition. This book examines the classical proofs of God's existence, and affirms their continued validity. It shows that human thought can connect with God and with other aspects of religious experience. Moreover, it depicts how Christian faith is reasonable, and is neither blind nor naked. Without reason, belief would degenerate into fundamentalism; but without faith, human thought can remain stranded on the reef of its own self-sufficiency. This book proposes that the human mind must be in partnership with the human heart in any quest for God. Paul Haffner is lecturer in systematic and dogmatic theology in Rome at the Pontifical Gregorian University, the Pontifical Lateran University and the Pontifical Athenaeum Regina Apostolorum. In this series he has published The Mystery of Creation, The Mystery of Mary and The Sacramental Mystery.