Nov 26 2007

Science and Faith

Paul Davies, a physicist and writer in the fields of cosmology, quantum field theory, and astrobiology, wrote an editorial in this Saturday’s New York Times (may require login) titled: Taking Science on Faith. In he writes:

The problem with this neat separation into “non-overlapping magisteria,” as Stephen Jay Gould described science and religion, is that science has its own faith-based belief system. All science proceeds on the assumption that nature is ordered in a rational and intelligible way. You couldn’t be a scientist if you thought the universe was a meaningless jumble of odds and ends haphazardly juxtaposed. When physicists probe to a deeper level of subatomic structure, or astronomers extend the reach of their instruments, they expect to encounter additional elegant mathematical order. And so far this faith has been justified.

I disagree with Davies’s formulation of this issue. He is saying that scientists must have faith in an ordered universe, but this is not true. Science does not make any claims about, nor is it premised on, any particular ultimate nature of reality. Science depends only upon methodological naturalism. That means that science proceeds as if the universe operates in an orderly way, because it has no choice. That is the nature of scientific methodology. It does not require that the universe actually is naturalistic.

Further, Davies is assuming that science has faith in its own assumptions. Rather, science is agnostic toward anything that it cannot test empirically, including its own assumptions. This may seem paradoxical, but it isn’t once you understand that science is only about method, not truth.

In essence, the philosophical basis of science is the notion that the only way humans can accumulate reliable knowledge about the universe is to formulate testable models of how the universe works and then test those models against reality. So science proceeds by those methods that are the only only ones that work, even in theory. Science does not have to have faith that these methods actually do work, it just acknowledges that they are all we have.

However, as Davies acknowledges, historically, acting as if we can understand the world through science has worked out very well. This does not prove that the world is naturalistic, just as you cannot prove anything in science, but it is an empirical meta-experiment of its own, and so far the evidence is strongly in favor of the hypothesis that the world is knowable.

Let us conduct a thought experiment. If we do live in a naturalistic world that predictably follows its own laws, then empirical hypothesis testing should be able to, over time, work out those laws and how the universe works. There would be no theoretical reason why science could not eventually understand any natural process. So far all the evidence seems to be pointing to the conclusion that we live in this type of universe.

What if, however, we lived in a “paranormal” universe – meaning that there were phenomena that did not follow naturalistic laws. Or perhaps our universe is somehow embedded in a grander universe that lies outside out ability to examine scientifically, but can occasionally intrude into our world. In other words, perhaps our reality, the reality to which we have access, is only a tiny slice of ultimate reality. Therefore, while we can only examine the tiny slice in which we live, it is subject to phenomena outside of that slice but part of the grander reality.

In such a paranormal universe, we would still only have science as a way to examine the world. Science could still mostly work. However, we would encounter phenomena that would not yield to scientific examination – that could not be explained or understood no matter how hard we tried. Centuries, even millennia, of examination would not penetrate these mysteries. They would forever lie outside the methodology of science as enduring anomalies.

We may, in fact, live in such a world. Science can only be agnostic toward any such untestable notions. Science does not require faith that we do not live in such a world. Either way, the methods of science are still valid and are still the only methods that produce a system of knowledge about how nature works. We can say, however, that the meta-experiment of science is working well, and so far we are not accumulating enduring anomalies.

Davies also addresses the question of why the laws of the universe are what they are, noting, as others have, that the laws of this universe appear to be fine-tuned for life (the so-called anthropic principle). He writes:

Over the years I have often asked my physicist colleagues why the laws of physics are what they are. The answers vary from “that’s not a scientific question” to “nobody knows.” The favorite reply is, “There is no reason they are what they are — they just are.” The idea that the laws exist reasonlessly is deeply anti-rational. After all, the very essence of a scientific explanation of some phenomenon is that the world is ordered logically and that there are reasons things are as they are. If one traces these reasons all the way down to the bedrock of reality — the laws of physics — only to find that reason then deserts us, it makes a mockery of science.

He advocates that we do not appeal to anything outside the universe as a way to explain the laws of physics but rather examine the question from within the laws of the universe. He concludes:

It seems to me there is no hope of ever explaining why the physical universe is as it is so long as we are fixated on immutable laws or meta-laws that exist reasonlessly or are imposed by divine providence. The alternative is to regard the laws of physics and the universe they govern as part and parcel of a unitary system, and to be incorporated together within a common explanatory scheme.
In other words, the laws should have an explanation from within the universe and not involve appealing to an external agency. The specifics of that explanation are a matter for future research. But until science comes up with a testable theory of the laws of the universe, its claim to be free of faith is manifestly bogus.

I agree with Davies that we should approach the question of the “metalaws” of physics – or the laws that govern what the laws of the universe are, as just another scientific question – meaning that we need to devise testable hypotheses. However, I strongly disagree with his conclusion that until we do science cannot free itself from faith. As I stated above, science cannot, and certainly does not have to, adhere to any belief or faith about the unanswered or unanswerable questions of ultimate reality. Science will remain agnostic toward any questions it cannot test or about which it cannot formulate a testable hypothesis.

Further, if it turns out that we cannot figure out a way to scientifically examine the question of why the laws of the universe are what they are, that does not mean that the laws are “reasonless.” There is nothing in the methodological naturalism that underlies science that says that we should be able to answer all questions. Some questions about reality, even in a purely naturalistic universe, may simply be beyond our reach. To be clear, Davies is not saying that the laws are without reason. He is, rather, criticizing this position, but he is saying that until we can formulate a testable hypothesis than we must either conclude that they are without reason or have faith that there is a reason. This is a false dichotomy – the real choice is that we can simply remain agnostic toward the question. And this agnosticism toward anything that cannot be tested is consistent with the methodological naturalism upon which science is based.


Other blog responses to this editorial:

Evolving Thoughts: Physicists on Science

12 responses so far