At yesterday’s Cosmic Variance, physicist Sean Carroll entered the fray about whether science can find evidence for the supernatural (aka “God”). Instead of fumbling about with the term “supernatural,” something I’ve preferred to avoid in favor of specifying characteristics of a god that one could look for, Carroll gets more specific than I by defining, helpfully, three types of phenomena.
- The silent: things that have absolutely no effect on anything that happens in the world.
- The hidden: things that affect the world only indirectly, without being immediately observable themselves.
- The lawless: things that affect the world in ways that are observable (directly or otherwise), but not subject to the regularities of natural law.
The first category is not, of course, subject to scientific investigation, and if that’s your kind of deistic or apophatic god, then of course science has nothing to say about it.
In the second category Carroll includes dark matter and quarks, which aren’t observable but have predictable consequences that can be tested scientifically.
Dark matter is unambiguously amenable to scientific investigation, and if some purportedly supernatural concept has similar implications for observations we do make, it would be subject to science just as well.
I’m a bit worried about the notion of a predictable and regular “supernatural” force that interacts with the world, because many of the commenters on this site and others will never accept regularity as evidence for anything we could conceive of as a god. It could, for example, be space aliens or some previously unknown physical law about which we should suspend judgment, although of course there’s no reason why a god couldn’t act with some regularity. It could, for example, answer the prayers of Jews but not Christians. And if it rains far more frequently when Native Americans do rain dances than when they don’t, well, it’s just some natural phenomenon we don’t understand.
Number three, the “lawless,” take us into the real of the real popular idea of “supernatural”: miracles and the like. I like the term “lawless” instead of “supernatural.” Carroll doesn’t see science as impotent before lawless phenomena, and I agree:
Let’s imagine that there really were some sort of miraculous component to existence, some influence that directly affected the world we observe without being subject to rigid laws of behavior. How would science deal with that?
The right way to answer this question is to ask how actual scientists would deal with that, rather than decide ahead of time what is and is not “science” and then apply this definition to some new phenomenon. If life on Earth included regular visits from angels, or miraculous cures as the result of prayer, scientists would certainly try to understand it using the best ideas they could come up with. To be sure, their initial ideas would involve perfectly “natural” explanations of the traditional scientific type. And if the examples of purported supernatural activity were sufficiently rare and poorly documented (as they are in the real world), the scientists would provisionally conclude that there was insufficient reason to abandon the laws of nature. What we think of as lawful, “natural” explanations are certainly simpler — they involve fewer metaphysical categories, and better-behaved ones at that — and correspondingly preferred, all things being equal, to supernatural ones.
But that doesn’t mean that the evidence could never, in principle, be sufficient to overcome this preference. Theory choice in science is typically a matter of competing comprehensive pictures, not dealing with phenomena on a case-by-case basis. There is a presumption in favor of simple explanation; but there is also a presumption in favor of fitting the data. In the real world, there is data favoring the claim that Jesus rose from the dead: it takes the form of the written descriptions in the New Testament. Most scientists judge that this data is simply unreliable or mistaken, because it’s easier to imagine that non-eyewitness-testimony in two-thousand-year-old documents is inaccurate that to imagine that there was a dramatic violation of the laws of physics and biology. But if this kind of thing happened all the time, the situation would be dramatically different; the burden on the “unreliable data” explanation would become harder and harder to bear, until the preference would be in favor of a theory where people really did rise from the dead.
There is a perfectly good question of whether science could ever conclude that the best explanation was one that involved fundamentally lawless behavior. The data in favor of such a conclusion would have to be extremely compelling, for the reasons previously stated, but I don’t see why it couldn’t happen.
. . . if the best explanation scientists could come up with for some set of observations necessarily involved a lawless supernatural component, that’s what they would do. There would inevitably be some latter-day curmudgeonly Einstein figure who refused to believe that God ignored the rules of his own game of dice, but the debate would hinge on what provided the best explanation, not a priori claims about what is and is not science.
This is where I agree with Sean, the philosopher Maarten Boudry, and, I think, Brother Blackford, and where we part company from P.Z Myers, The Great Decider, Eugenie Scott and the NCSE—and nearly everyone else. At least I (and probably Sean) could envision theoretical cases where we’d see behavior as sporadic and lawless—and provisionally indicative of a god. Others would not.
And, lest we despair at all having settled into positions that are refractory to further change—which is probably the case—this debate has not been futile. It’s enabled us to clarify our own notion of what we mean by “supernatural,” what we mean by “the domain of science,” and what, if anything, could it mean to test for a god—or if even whether we find the idea of a god coherent. I’ve much appreciated the back and forth we’ve all had, and am grateful to Sean for weighing in.