 This argument about God and the possibility of evil has been disputed by theists such as Alvin Plantinga, who do not hold that God’s existence implies the existence of a maximally good world, but do hold that God seeks to create as good a world as he  can.[10]  Theists such as Plantinga allow for there to be evil that is  unnecessary for any greater good that outweighs it. An evil of this kind involves free decisions of non-divine agents, which God does not prevent, but which these other agents can prevent. Plantinga contends that God is not wrong to permit an evil of this kind, since God cannot bring about a vital good, the existence of free human agents, without there being such an evil. Alternatively, it might be argued that God does no wrong in this sort of case, because he does not know how to do better (knowledge of the future free actions of created agents being impossible). However, as an omnipotent God is not required to have power over the free decisions of non-divine agents, it follows that on these views, his omnipotence and moral perfection are compatible, roughly to the extent indicated earlier in our discussion of the view that God’s existence implies a maximally good world. Of course, nothing that has been said here answers the question of how much, if any, evil is compatible with the existence of the traditional God. This question is central to the problem of evil for theism.