July 2009

One frustrating aspect of our discussion about the compatibility of science and religion was the amount of effort expended arguing about definitions, rather than substance. When I use words like “God” or “religion,” I try to use them in senses that are consistent with how they have been understood (at least in the Western world) through history, by the large majority of contemporary believers, and according to definitions as you would encounter them in a dictionary. It seems clear to me that, by those standards, religious belief typically involves various claims about things that happen in the world — for example, the virgin birth or ultimate resurrection of Jesus. Those claims can be judged by science, and are found wanting.

Some people would prefer to define “religion” so that religious beliefs entail nothing whatsoever about what happens in the world. And that’s fine; definitions are not correct or incorrect, they are simply useful or useless, where usefulness is judged by the clarity of one’s attempts at communication. Personally, I think using “religion” in that way is not very clear. Most Christians would disagree with the claim that Jesus came about because Joseph and Mary had sex and his sperm fertilized her ovum and things proceeded conventionally from there, or that Jesus didn’t really rise from the dead, or that God did not create the universe. The Congregation for the Causes of Saints, whose job it is to judge whether a candidate for canonization has really performed the required number of miracles and so forth, would probably not agree that miracles don’t occur. Francis Collins, recently nominated to direct the NIH, argues that some sort of God hypothesis helps explain the values of the fundamental constants of nature, just like a good Grand Unified Theory would. These views are by no means outliers, even without delving into the more extreme varieties of Biblical literalism.

Furthermore, if a religious person really did believe that nothing ever happened in the world that couldn’t be perfectly well explained by ordinary non-religious means, I would think they would expend their argument-energy engaging with the many millions of people who believe that the virgin birth and the resurrection and the promise of an eternal afterlife and the efficacy of intercessory prayer are all actually literally true, rather than with a handful of atheist bloggers with whom they agree about everything that happens in the world. But it’s a free country, and people are welcome to define words as they like, and argue with whom they wish.

But there was also a more interesting and substantive issue lurking below the surface. I focused in that post on the meaning of “religion,” but did allude to the fact that defenders of Non-Overlapping Magisteria often misrepresent “science” as well. And this, I think, is not just a matter of definitions: we can more or less agree on what “science” means, and still disagree on what questions it has the power to answer. So that’s an issue worth examining more carefully: what does science actually have the power to do?

I can think of one popular but very bad strategy for answering this question: first, attempt to distill the essence of “science” down to some punchy motto, and then ask what questions fall under the purview of that motto. At various points throughout history, popular mottos of choice might have been “the Baconian scientific method” or “logical positivism” or “Popperian falsificationism” or “methodological naturalism.” But this tactic always leads to trouble. Science is a messy human endeavor, notoriously hard to boil down to cut-and-dried procedures. A much better strategy, I think, is to consider specific examples, figure out what kinds of questions science can reasonably address, and compare those to the questions in which we’re interested.

Here is my favorite example question. Alpha Centauri A is a G-type star a little over four light years away. Now pick some very particular moment one billion years ago, and zoom in to the precise center of the star. Protons and electrons are colliding with each other all the time. Consider the collision of two electrons nearest to that exact time and that precise point in space. Now let’s ask: was momentum conserved in that collision? Or, to make it slightly more empirical, was the magnitude of the total momentum after the collision within one percent of the magnitude of the total momentum before the collision?

This isn’t supposed to be a trick question; I don’t have any special knowledge or theories about the interior of Alpha Centauri that you don’t have. The scientific answer to this question is: of course, the momentum was conserved. Conservation of momentum is a principle of science that has been tested to very high accuracy by all sorts of experiments, we have every reason to believe it held true in that particular collision, and absolutely no reason to doubt it; therefore, it’s perfectly reasonable to say that momentum was conserved.

A stickler might argue, well, you shouldn’t be so sure. You didn’t observe that particular event, after all, and more importantly there’s no conceivable way that you could collect data at the present time that would answer the question one way or the other. Science is an empirical endeavor, and should remain silent about things for which no empirical adjudication is possible.

…

What Questions Can Science Answer?Read More »