This book is not intended for the popular reader. It is a rather detailed and technical criticism of the philosophical basis of the Augustinian treatment of the problem of evil. The author does not presume to have fathomed this eternal mystery nor to have reformulated the doctrine of sin. If, however, he has set forth in a true light the historic theory which for centuries has dominated Christian thought, and has shown the absolute necessity of a reconstruction of the doctrine of sin, then in a measure he has realized his purpose. - Preface.