In this universe, even what is called evil, when it is rightly ordered and kept in its place, commends the good more eminently, since good things yield greater pleasure and praise when compared to the bad things. For the Omnipotent God, whom even the heathen acknowledge as the Supreme Power over all, would not allow any evil in his works, unless in his omnipotence and goodness, as the Supreme Good, he is able to bring forth good out of evil. What, after all, is anything we call evil except the privation of good? In animal bodies, for instance, sickness and wounds are nothing but the privation of health. When a cure is effected, the evils which were present (i.e., the sickness and the wounds) do not retreat and go elsewhere. Rather, they simply do not exist any more. For such evil is not a substance; the wound or the disease is a defect of the bodily substance which, as a substance, is good. Evil, then, is an accident, i.e., a privation of that good which is called health. Thus, whatever defects there are in a soul are privations of a natural good. When a cure takes place, they are not transferred elsewhere but, since they are no longer present in the state of health, they no longer exist at all.
Augustine of Hippo, The Enchiridion on Faith Hope and Love
evil, god, good