  When we consider, however, the works of medieval philosophers who address the problem of evil, the “atheistic problem” is not to be found. Since these figures believed that the arguments of natural theology demonstrated the existence of God, the problem that evil presented for them was different from that engaged by present-day philosophers. In present-day terminology, medieval philosophers did not engage the “evidential” problem of evil: rather, they engaged the “aporetic” problem of evil, in order to try to resolve the apparent logical incompatibility between God's attributes and the existence of evil.  [On the distinction between these problems, see Adams and Adams (1990), pp. 1–3.]  The problem, therefore, was taken to be that of explaining the compatibility of the existence of evil with divine moral purity or holiness. These philosophers believed that God is the author of everything that exists, and given that evil is one of the things that exists, it might seem that God is therefore the author of evil. And if an agent is an “author of evil,” he is therefore implicated in the evil and cannot be morally pure or holy. Thus, God cannot be morally pure nor holy. Let's call this version of the problem of evil the “holiness problem.” Before moving on, it should be noted that in light of the fact that Leibniz and his predecessors shared a commitment to God's existence, one might think that their approach to the problem of evil begs the question against the atheistic critic who charges that the existence of evil provides evidence that God does not exist.  But this issue simply did not arise for Leibniz and his predecessors, given their antecedent belief in God's existence, and therefore it is inappropriate to charge these philosophers with begging the question.