Sean Carroll on the nature of science

July 16, 2009 • 7:22 am

Over at Cosmic Variance, Sean Carroll (the physics one) has a nice essay on the nature of a scientific question.  He begins with a discussion of the empirical content of religious beliefs, which some (including journalist Jeremy Manier, who comments on this blog) seem to find unimportant or irrelevant in discussing the compatibility of science and faith:

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.

Carroll then clarifies what he sees as the main endeavor of scientists; the construction of theories:

The definition of theory is also occasionally troublesome, but the humble language shouldn’t obscure the potential reach of the idea: whether we call them theories, models, hypotheses, or what have you, science passes judgment on ideas about how the world works.

And that’s the crucial point. Science doesn’t do a bunch of experiments concerning colliding objects, and say “momentum was conserved in that collision, and in that one, and in that one,” and stop there. It does those experiments, and then it also proposes frameworks for understanding how the world works, and then it compares those theoretical frameworks to that experimental data, and — if the data and theories seem good enough — passes judgment. The judgments are necessarily tentative — one should always be open to the possibility of better theories or surprising new data — but are no less useful for that.

He says this about multiverse (multiple-universe) “theories”, which theistic evolutionists like Kenneth Miller dismiss as “Hail Marys,” desperation passes thrown out by scientists to explain why physical constants appear to be “fine tuned” for the existence of life. Here is what Miller says about multiverses in his book Only a Theory:

Believers . . . are right to remind skeptics and agnostics that one of their favored explanations for the nature of our existence involves an element of the imagination as wild as any tale in a sacred book: namely, the existence of countless parallel simultaneous universes with which we can never communicate and whose existence we cannot even test. Such belief also requires an extraordinary level of “faith” and the nonreligious would do well to admit as much.

In fact, multiverses are not something concocted by scientists to save their cookies; they grow naturally out of some theories of physics.  As Carroll argues:

The same logic applies, for example, to the highly contentious case of the multiverse. The multiverse isn’t, by itself, a theory; it’s a prediction of a certain class of theories. If the idea were simply “Hey, we don’t know what happens outside our observable universe, so maybe all sorts of crazy things happen,” it would be laughably uninteresting. By scientific standards, it would fall woefully short. But the point is that various theoretical attempts to explain phenomena that we directly observe right in front of us — like gravity, and quantum field theory — lead us to predict that our universe should be one of many, and subsequently suggest that we take that situation seriously when we talk about the “naturalness” of various features of our local environment. The point, at the moment, is not whether there really is or is not a multiverse; it’s that the way we think about it and reach conclusions about its plausibility is through exactly the same kind of scientific reasoning we’ve been using for a long time now. Science doesn’t pass judgment on phenomena; it passes judgment on theories.

Carroll then explains why certain religious claims are indeed empirical claims about the real world, and in that sense are scientific:

Now let’s turn to a closely analogous question. There is some historical evidence that, about two thousand years ago in Galilee, a person named Jesus was born to a woman named Mary, and later grew up to be a messianic leader and was eventually crucified by the Romans. (Unruly bloke, by the way — tended to be pretty doctrinaire about the number of paths to salvation, and prone to throwing moneychangers out of temples. Not very “accommodating,” if you will.) The question is: how did Mary get pregnant?

One approach would be to say: we just don’t know. We weren’t there, don’t have any reliable data, etc. Should just be quiet.

The scientific approach is very different. We have two theories. One theory is that Mary was a virgin; she had never had sex before becoming pregnant, or encountered sperm in any way. Her pregnancy was a miraculous event, carried out through the intervention of the Holy Ghost, a spiritual manifestation of a triune God. The other theory is that Mary got pregnant through relatively conventional channels, with the help of (one presumes) her husband. According to this theory, claims to the contrary in early (although not contemporary) literature are, simply, erroneous.

There’s no question that these two theories can be judged scientifically. One is conceptually very simple; all it requires is that some ancient texts be mistaken, which we know happens all the time, even with texts that are considerably less ancient and considerably better corroborated. The other is conceptually horrible; it posits an isolated and unpredictable deviation from otherwise universal rules, and invokes a set of vaguely-defined spiritual categories along the way. By all of the standards that scientists have used for hundreds of years, the answer is clear: the sex-and-lies theory is enormously more compelling than the virgin-birth theory.

Finally, he goes into the methodological naturalism/philosophical naturalism distinction that some people, including Mooney and Kirshenbaum in their book Unscientific America, use as a stick to beat those mean atheists. As Russell Blackford has shown, this distinction is really a red herring in the discussion about whether science and faith are compatible.

Could science, through its strategy of judging hypotheses on the basis of comparison with empirical data, ever move beyond naturalism to conclude that some sort of supernatural influence was a necessary feature of explaining what happens in the world? Sure; why not? If supernatural phenomena really did exist, and really did influence things that happened in the world, science would do its best to figure that out.

It’s a nice piece, and I doubt that anyone could construe it as “militant” or “shrill”. Go read the whole thing.

Sean Carroll on the compatibility of faith and science

June 23, 2009 • 1:29 pm

Over at his website, Cosmic Variance, physicist Sean Carroll weighs in on the faith/science debates.  Carroll has always been a vociferous (note: that doesn’t mean “strident” or “militant”) atheist, and so we shouldn’t be surprised that he finds faith and science incompatible.  However, he does so not for philosophical reasons, but simply from seeing the different conclusions reached by the two “magisteria”:

The reason why science and religion are actually incompatible is that, in the real world, they reach incompatible conclusions. It’s worth noting that this incompatibility is perfectly evident to any fair-minded person who cares to look. Different religions make very different claims, but they typically end up saying things like “God made the universe in six days” or “Jesus died and was resurrected” or “Moses parted the red sea” or “dead souls are reincarnated in accordance with their karmic burden.” And science says: none of that is true. So there you go, incompatibility.

While Carroll says that this form of incompatibility is different from the one I see, I don’t think there’s a substantive difference.  The reason that science and faith reach different conclusions is precisely because one way of knowing, science, bases its conclusions on evidence and reason, while the other way of “knowing,” religion, uses revelation and faith.  That’s the incompatibility I see, and of course it will lead to an incompatibility of conclusions. As Carroll recognizes, this trumped-up view of “faith” as belief in some nonspecific deity who doesn’t actually do anything, was the view floated by Stephen Jay Gould as part of his NOMA concept. (Gould also made the ridiculous claim that ethics and morality were the purview of religion, neglecting two millennia of secular discussion of ethics.)

But Carroll is absolutely on the money when he describes how the enlightened faithful and faithful scientists arrive at a pronouncement of “compatibility”:

The favored method of those who would claim that science and religion are compatible — really, the only method available — is to twist the definition of either “science” or “religion” well out of the form in which most people would recognize it. Often both.

Of course, it’s very difficult to agree on a single definition of “religion” (and not that much easier for “science”), so deciding when a particular definition has been twisted beyond usefulness is a tricky business. But these are human endeavors, and it makes sense to look at the actual practices and beliefs of people who define themselves as religious. And when we do, we find religion making all sorts of claims about the natural world, including those mentioned above — Jesus died and was resurrected, etc. Seriously, there are billions of people who actually believe things like this; I’m not making it up. Religions have always made claims about the natural world, from how it was created to the importance of supernatural interventions in it. And these claims are often very important to the religions who make them; ask Galileo or Giordano Bruno if you don’t believe me.

But the progress of science over the last few centuries has increasingly shown these claims to be straightforwardly incorrect. We know more about the natural world now than we did two millennia ago, and we know enough to say that people don’t come back from the dead. In response, one strategy to assert the compatibility between science and religion has been to take a carving knife to the conventional understanding of “religion,” attempting to remove from its purview all of its claims about the natural world.

It continually amazes me that theologians like John Haught or scientists like Francis Collins can get away with a definition of “religion” that is completely at odds with how most real non-Ph.D-holding humans practice their faith in the real world.  To enforce a compatibility between faith and science, you have to water down “faith” until it becomes a vague deism that doesn’t permit its god to interfere in the working of the universe.  And that’s simply not the way that most people construe their faith. Note to accommodationists:  religion is NOT NECESSARILY the form of faith practiced by university theologians or academic scientists.

Carroll goes on to reject the God hypothesis, and doesn’t pull any punches.

Scientifically speaking, the existence of God is an untenable hypothesis. It’s not well-defined, it’s completely unnecessary to fit the data, and it adds unhelpful layers of complexity without any corresponding increase in understanding. Again, this is not an a priori result; the God hypothesis could have fit the data better than the alternatives, and indeed there are still respected religious people who argue that it does. Those people are just wrong, in precisely analogous ways to how people who cling to the Steady State theory are wrong. Fifty years ago, the Steady State model was a reasonable hypothesis; likewise, a couple of millennia ago God was a reasonable hypothesis. But our understanding (and our data) has improved greatly since then, and these are no longer viable models. The same kind of reasoning would hold for belief in miracles, various creation stories, and so on.

So, when the faithful — or the Templeton Foundation — tell you that religion allows us to answer the Bigger and Deeper Questions about Life, ask yourself, “What are the answers?.  Do we have any answers?” I have yet to find a single “truth” about our place in the universe or about the meaning of life that has been supplied by faith.  And so Templeton and its minions continue to waste millions of dollars addressing the Big Questions, but of course not getting any answers to them.  At least science gives us some answers.