I think that the Fine Tuning Argument (FTA) is the best theistic argument. I also think that the Problem of Evil (POE) is the best atheistic argument. Recently, I commented on a dialectical strategy that theists could use in response to the problem of evil. Given that fine tuning is very surprising given atheism and evil is very surprising given theism, these arguments cancel each other out. In other words, the probabilities are balanced and we’re basically left with agnosticism. The theist and atheist could put forward other arguments to raise the probability of their respective positions, but they arguably will have given up their strongest arguments.
That’s one way to go. But it also occurred to me that these arguments, construed probabilistically, are parallel in form. If true, then a parallel rebuttal strategy could be used in response to each argument. I’m thinking specifically of the multiverse response to the FTA. Briefly, if there were an infinite, or near-infinite, number of universes, then the fact that ours has the constants necessary to permit intelligent life is less surprising. Similarly, one could take a multiverse line with respect to the POE. It turns out I’m not original in suggesting this. Some theists (e.g. Klaus Kraay, Robin Collins, Donald Turner) have argued that if theism were true, one would expect there to be a multiverse. If there is a God, we’d expect him to create the maximum number of creation-worthy worlds, where ‘creation-worthy’ is defined as having a greater balance of good over evil in the long run. On this assumption, it wouldn’t be surprising that some worlds contain evil (even a lot of it) and we just happen to be in one of those worlds. The parallel to the atheist’s strategy with respect to the FTA should be obvious.
Of course, the theist would be sacrificing the FTA to the POE in this event, and the theist would have to weigh whether this dialectical move would be a net loss or net gain. I’m inclined to think that it would be a gain. Even without the FTA, the theist still has several weapons in the arsenal (cosmological arguments, moral arguments, pragmatic arguments) whereas without the POE, the atheist’s reserve is less formidable. I’d make a case that the argument from hiddenness is still quite strong, but it doesn’t seem to resonate with the same rhetorical force of the POE. I don’t know how the atheist should best respond, especially if he relies on the multiverse objection to the FTA. Perhaps it’s best to find another response to the FTA, but that doesn’t necessarily prevent the theist from appealing to a multiverse to counter the POE. I suppose the atheist could argue that the multiverse is ad hoc with respect to the POE. But it isn’t entirely clear that the theist’s use of multiverse is any more ad hoc than the atheist’s use of it. In a debate context, then, this may be the theist’s best strategy.