John McGuckin examines early writings of Christian theologians about conscience. These relied upon the Scriptures and upon Plato, Aristotle, and others, and they regularly grappled with the positive and negative possibilities of conscience. But Christian writers made religious inquiries. St. Paul wrote about conscience in connection with a law “written on the heart,” a guide to everyone, but fallible and in need of the grace of Christ. The Greek fathers, led by Origen, emphasized conscience as an awareness of divine things, albeit impaired by man’s fall, yet still oriented to God and to obedience to moral norms. The Latin fathers, led by Augustine, emphasized humanity’s corruption after the fall and need for divine grace. Thus, conscience may convict, but might not provoke a person to goodness. Only loving God could do this. In both Latin and Greek thought, therefore, conscience was more than an inner voice instructing about right and wrong. It was a set of reflections on the spiritual identity of human beings.