l, or apparent evil in the natural order, according to Aquinas. Blindness, for example, is an absence of sight, and not a positive thing.
There is then the question of the choice of human beings to engage in clearly wicked acts. Both Plato and Aquinas believed that even when human beings engage in such acts, and did so with their full will and intention, they are doing so in the belief that they are doing good and not evil. In other words, for
example, "The adulterer never wills his act solely as an evil act but rather for that aspect of his act that is good and affords
Aquinas then addressed the question of why God would have allowed defects in man's physical nature (blindness, for example) and in his moral actions (adultery, for example). Aquinas argued that "the perfection of the universe required the existence of various kinds of beings, including corruptible as well as incorruptible beings, thus providing the possibility, but not the necessity, for defect and suffering" (Stumpf 198).
With respect to the moral order, Aquinas sets forth the most compelling argument to explain man's apparent evil---that is, man is free to choose how to behave. Even in that sense, evil is not a necessity, but is only a possibility within the context of man's freedom. In other words, God cannot be said to have willed that evil would exist, but only that He willed man to be free and therefore allowed evil to be possible:
The possibility of evil in the unavoidable corollary of the greater good that comes from man's freedom to love and serve God. Aquinas therefore concludes that God is not the cause of evil even though by creating beings with freedom He permitted the possibility of it. Moral evil . . . is the product of the will whereby the essentially good element in the willed act lacks its true end (Stumpf 198).
To Martin Buber in Good and Evil, evil is the separation from God and the choice against life, which occurs in the act o...