In this post, I will explore a common accusation made against the fine-tuning argument for theism, namely that it depends on god-of-the-gaps reasoning. This kind of reasoning uses God as an explanation for phenomena that the natural sciences do not currently understand. This strategy is precarious because, as scientific knowledge grows large enough to fill in these gaps in our understanding, what was previously explained by God eventually gets replaced by naturalistic explanations. God thereby becomes superfluous.
Why do naturalists often accuse theists of god-of-the-gaps reasoning with respect to the fine-tuning argument? Well, it is true that our current understanding of the multiverse only permits a very narrow range of worlds hospitable to life, but perhaps future scientific discoveries will uncover more hospitable worlds than we had originally bargained for! So, says the naturalist, the theist’s best policy is to wait and see how science progresses rather than make premature appeals to God on the basis of incomplete evidence.
Prudent theists typically heed these warnings, despite the fact that scientific models consistently fail to explain fine-tuning. For example, Stephen Hawking’s construal of M-Theory suggests that 10 to the 500 worlds are compatible with the known laws of physics. Assuming (and this is an act of generosity!) that each of those worlds is actual, still only a small fraction of them are hospitable. And of the hospitable ones, the odds of any of them generating living creatures who are also self-conscious agents are still quite low.
However, the failure of Hawking’s proposal does not equal the failure of naturalism; other proposals may surface which are far superior to M-Theory and which meet the probabilistic demands posed by the problem of fine-tuning. At the very least, then, theists and naturalists alike need to be very tentative in their conclusions about what a multiverse can explain.
But the fine-tuning discussion need not end with caution about the prospects of future of scientific research. Assuming that multiple worlds actually exist, the discussion is wide open for exploring deeper philosophical problems such as why the fundamental laws governing the multiverse are structured in such a way as to be capable of generating complex worlds – indeed hospitable worlds containing self-conscious agents – in the first place! This is a philosophical problem – not a scientific one – because it concerns the basic logic of the laws themselves, laws which are presupposed (and therefore not explained) by scientific endeavour.
In the past, philosophically inclined theists have pointed to the elegance, consistency, and mathematical form of the laws of nature to support of their position. But they have neglected to ask why (on the multiverse hypothesis) these same laws have the potential to generate hospitable worlds at all? Is this not a fact in need of explanation? Surely there might have been elegant laws without that potential. But then why didn’t those laws exist instead of the actual ones? Indeed, why are the actual laws so fecund?
Naturalism doesn’t seem to have an answer to this question, but theism might. If a benevolent God exists, then he may have good reason to create ‘fecund’ laws that yield such a plethora of worlds. This might seem like a huge waste of time and resources on God’s part if his only purpose is to make living creatures. But if He also values a process that generates creativity, diversity, complexity, and interdependence – not just living creatures – then a rich plethora of worlds may be in order.
What do you, the reader, think? If a multiverse exists, does the fecundity of its basic laws need some kind of explanation? Why or why not?
 I.e. why are the laws so productive and fruitful, when they might not have been?