In a recent podcast from Conversations from the Pale Blue Dot, guest Stephen Law offers a refreshing and convincing argument against many theist positions. I like to call this the argument from symmetry. It essentially goes like this: any argument for the existence of a good god can be applied just as successfully to support the existence of an evil god. And, since Christians are wedded to the idea of a good god, they must give up any argument that can be used to argue equally for either a good or bad god.
An example that Law offers is the free will theodicy many Christians use to support the idea that a good God is logically compatible with a world filled with evil, such as ours is. Free will theodicy says that a good God wants us to do genuinely good things, but to do so we must be free to choose these things of our own volition. If we did good things automatically, without thinking, they would simply be autonomous actions, not genuinely good deeds. However, granting us the freedom to choose good necessarily requires us to be able to opt for bad instead, hence the presence of evil in the world despite God’s good nature.
By symmetry, we can apply precisely the same argument for why an evil God is logically consistent with the presence of many good things in the world. All we need do is copy the above argument and reverse the “polarity” of all the moral language: an evil God wants us to do genuinely evil things, but to do so we must be free to choose these things of our own volition. If we did evil things automatically, without thinking, they would simply be autonomous actions, not genuinely evil deeds. However, granting us the freedom to choose evil necessarily requires us to be able to opt for good instead, hence the presence of good in the world despite God’s evil nature.
Since both points of view are equally valid logically, yet result in contradictory conclusions, the logic of both points of view must be fundamentally flawed, i.e. the theodicy is invalid. (I suppose one could argue that there exist two gods, one good and one evil, but which one created humans?)
The argument from symmetry applies to other proffered explanations for evil in the world. For instance, Christians often claim that we cannot ever understand why evil exists in the world because the purpose of God is inscrutable. Therefore, a good God may be compatible with a world containing evil, we just cannot understand why. But by symmetry, the same can be said of an evil God: he is compatible with a world containing good, we just cannot understand why, because his purpose is inscrutable.
A similar approach can be taken with the ontological argument, although this is not a particularly convincing argument to begin with. The ontological argument claims that we can conceive of a god that is more good than any other conceivable god. And, since such a superlatively good god would surely be even more good in reality than in our imagination, he must really exist. This is a pretty weak argument: one cannot simply poof something into physical existence just by thinking about it. However, for those who wish to rebut it, the argument from symmetry is all that is needed: we can conceive of a god that is more evil than any other conceivable god. And, since such a superlatively evil god would be surely more evil in reality than in our imagination, he must really exist. (Ebon Musings notes that the ontological argument can be used to pop into existence just about any object one wishes. For instance, the Benedictine monk Gaunilo used it to “prove” the existence of a perfect island.)
In short, the argument from symmetry is effective not only because it rebuts many apologist arguments, but because it does so by striking at the foundational structure of the argument without even requiring recourse to evidence.