The evidential problem of evil points to the improbability that the amount of evil we see in the world – particularly gratuitous evil – would exist if an omnipotent, omnibenevolent God exists. The argument usually takes the following form:
(1) If God exists, gratuitous evil would not exist
(2) Gratuitous evil exists
(3) Therefore God does not exist
Many theists attempt to undermine this argument by attacking the veracity of premise two. For example, William Lane Craig and William Alston argue that humans are not in an epistemic place to judge any act of evil as gratuitous since we cannot see the big picture of history. For all we know, an act of seemingly gratuitous evil will result in a greater good years or even centuries from now, either in the life of the person who experienced the evil or in the life of another person in another country. Our cognitive limitations should not be used as evidence that gratuitous evil exists. At best we must remain agnostic on the question.
This is an appeal to the Greater-Good Defense, which argues that God has a morally sufficient reason for permitting all evils—including those that appear gratuitous to us—such as using them to bring about some greater good that could not have been brought about apart from those evils.
In the latest issue of Philosophia Christi, Kirk R. MacGregor provides some reasons for thinking that this response to the evidential problem of evil is misguided. Just because our cognitive and temporal limitations make it impossible for us to prove that any act of evil is truly gratuitous does not mean that gratuitous evil does not exist. He argues that the belief that some evils are gratuitous is a properly basic belief. For example, we do not believe that every time we are bitten by a mosquito or stub our two that these evils have some greater purpose or will be used to accomplish a greater good. Such things make virtually no difference in our own lives, yet alone on the grand scheme of things. Given the proper basicality of belief in gratuitous evil, MacGregor says the burden of proof is on those who would deny the existence of gratuitous evils, and to meet their burden of proof they must explain how every instance of gratuitous evil actually results in some greater good. This is not possible, and thus the person who believes in the existence of gratuitous evil is prima facie justified in maintaining that belief, even given his cognitive and temporal limitations.