In order to make sense of St. Augustine’s definition of evil as the absence of good, it is helpful to know how he came up with it. It is true that St. Augustine was a Manichean before he became a Christian. Manichaeism, a Persian Dualist religion, is the belief in both a good and an evil god. According to Manichaeism, the kingdom of light and the kingdom of darkness are engaged in an eternal war against each other. In the process of his conversion, St. Augustine approached Christianity from the perspective of a Manichean. He challenged the existence of the Manichean god of evil, and came up with the conclusion that only a good god exists. This is how St. Augustine came to question the presence of evil. He realized that the Christian teachings about a good god who creates only good things and the existence of evil contradict each other.
Although it is difficult to think of evil as some sort of an illusion, I do not think that St. Augustine’s definition of evil is philosophically or existentially problematic. To begin, I believe that God is a good god, and that all things come from him. It follows that earthly goods, in addition to everything else that exists, are good consequently. I also hold that God is, by His nature, incapable of creating things that are not good. These Christian beliefs about the benevolence of God and the goodness of His creation render