In Theism and Explanation, Gregory Dawes tries to get to the bottom of some very important questions: Could a theistic explanation ever, even in principle, be a good explanation for anything? What would a successful theistic explanation look like? How strong could a theistic explanation be?
The answer to the first question, “Could a theistic explanation be a good explanation (at least in principle)?” is answered in the affirmative. Dawes rejects the idea that methodological naturalism, as practiced by the sciences, must exclude theistic explanation. He draws on W.V. Quine’s definition of naturalism, which is basically the notion that whatever we refer to as part of reality must have some observable consequences that we can test. Dawes sees the common understanding of “methodological naturalism” as empty: it says that we can only account for the observable world in terms of physical things, but for what reason should this methodology be adopted? Natural explanations may have an excellent track record: they have always proven correct and they have systematically replaced practically every supernatural explanation that man has believed. Dawes admits that the great success of natural explanations counts strongly against a proposed theistic explanation, but still believes in the possibility of a successful theistic explanation. Dawes examines several ‘silver bullet’ objections to the possibility of a successful theistic explanation, but finds them all unsatisfying. If one agrees that there are no successful theistic explanations, not because there could never be such a thing, but because every proposed theistic explanation has failed, then Dawes’ position seems to be a much more damaging position to advocate with respect to the believers. “It is not that I refuse to entertain a supernatural explanation,” an atheist might say to a theist, “I simply disbelieve in God because every supernatural explanation ever proposed has wound up a spectacular failure. I gave Theism an honest chance, but it turned out it was empty.”
If successful theistic explanations are at least possible, then how would we recognize it? By what criteria would we judge it? A successful theistic explanation must, at least, live up to the same standards as any other type of explanation. It must be assessed in competition with other explanations and shown to be the strongest by way of its simplicity, its explanatory power (how well it explains the facts), its explanatory scope (the number of facts it explains), and its degree of testability, among other things. Dawes also argues that a theistic explanation must answer the question: Why did God bring this state of affairs into existence? A proper explanation is one that shows that the evidence we have is more likely to exist if it is true. It follows that to postulate God as an explanation, you must show why the evidence we have is most probable under the assumption that God exists. Why did God make A rather than B? We must look to God’s properties (perfect goodness, perfect knowledge, etc.) and try to show that it follows from those properties that God is likely to make A rather than B.
There are philosophers who object to the very idea that humans could predict the actions of a deity. After all, God is supposedly greater and grander than mere humans can comprehend. If we cannot even hope to predict what God might bring about, then theistic explanations are hopeless, and could never constitute a good explanation for anything by their very nature. Dawes agrees that we may not understand a hypothetical deity completely; we might not always predict the deity’s actions with 100% accuracy. But he finds this objection empty: “[F]rom the fact that our ability to make such judgements is limited, it does not follow that we have no ability at all.” I would add that those who subscribes to Judeo-Christian theology could not consistently advocate what we might call “theological skepticism” because the book of Genesis says that we are made in God’s image, and that surely entails that we are like God in some way, and ought to be able to understand his actions and desires, if only imperfectly.
In the end, Dawes concludes that theistic explanations are bound to be weak explanations (in comparison to other, more scientific, types of explanation) for several reasons:
1. They are difficult or impossible to test. Dawes reminds us that natural disasters are often “explained” as God’s punishment for a wicked people. But how exactly could we test this? Dawes does not see how. I think this could be tested: we could try to come up with some criteria that denote the wickedness of a city (or state, or nation) and then chart the number of natural disasters that happen to cities (or states, or nations) with varying scores. Perhaps the cities with the most sexual misconduct are hit more often with earthquakes and hurricanes than the more Puritan cities. That I know of no one has ever done a study such as this, so who knows what the results might be?
2. Background knowledge. Our background knowledge should include the fact that theistic explanations have failed again and again over the course of history, and this will significantly lower our confidence that a theistic explanation is correct (After all, if a certain type of explanation has failed one hundred times in a row, no one would have much confidence that it would succeed the hundred-and-first time around). Some examples of failed theistic explanations:
a. Lightning and Earthquakes were once attributed to the activities of the gods.
c. Biological heredity was once thought to be supernatural until Watson and Crick described its completely material basis: DNA.
d. The seemingly purposeful complexity of life was once seen as evidence for God’s existence until Charles Darwin showed that evolution by natural selection was a better explanation.
3. Ontological Parsimony. Postulating a God means that not only are we postulating a new entity, but a completely new kind of entity: a supernatural being. This lack of parsimony relative to natural explanations counts strongly against a theistic explanation, although it does not completely rule out such an explanation.
4. Lack of Informativeness. Theistic explanations appear to be very imprecise in comparison to physical explanations, which often make very precise predictions.
Overall, Theism and Explanation is a very sound and sensible book. It refutes most (if not all) of the fallacious attempts to divorce the question of God’s existence from our observations about the world. It provides believers with a blueprint for formulating a logically sound argument-to-the-best-explanation for God’s existence, and instructs nonbelievers on how to recognize a good argument-to-the-best-explanation for God’s existence (should they come across one). It represents a clear and well-reasoned paradigm in which we can consider theistic explanations, and so I highly recommend it.
 R.J. Hankinson, Cause and Explanation in Ancient Greek Thought (New York: Oxford University Press, 1998), p.8
 See Isaac Newton’s letter to Richard Bentley, as quoted in Dennis Richard Danielson, The Book of the Cosmos: Imagining the Universe from Heraclitus to Hawking (Cambridge, MA: Basic Books, 2001), p.228
 Allessandra Celletti and Ettore Perozzi, Celestial Mechanics: The Waltz of the Planets (New York: Springer Books, 2007), p.91
 William Paley, Natural Theology: Or Evidences of the Existence of and Attributes of a Deity, Collected from the Appearances of Nature (London, 1802).