Abstract

St. Augustine’s De Libero Arbitrio is by far the most important of the saint’s philosophical works. Although he wrote it fairly soon after his conversion and before the Pelagian controversy broke out, he had no need to change his views in later life, but continued to recommend that it should be read. In spite of its title, it is not a discussion on the nature of free will, nor an analysis of the psychological circumstances in which choice is exercised. The author himself tells us, in his Retractations, that it was written to answer the Manichaean objection to Christianity that, since the presence of evil is undeniable, it is inconceivable that God can be both almighty and infinitely good. The saint in his reply traced evil to sin, and sin to free will. Hence the title of this book. Since it was written before Pelagianism arose, there was no need to go into the difficulties of grace and free will, so the treatise is philosophical rather than theological. It contains the fullest exposition in any of his writings of his proof from reason for the existence of God, and in setting out the argument he deals with some of the deepest problems in philosophy.