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You can’t believe in evolution

[This is a re-posting of an earlier post, with the comments turned on this time. Unfortunately, current events–read: “Kansas” [Oct24, 2005: good grief, and now Dover!]–keep making it relevant. It’s amazing that almost a century after the Scopes monkey trial, we STILL have to argue about this nonsense.]

Evolution is said to be one dogma among many, nothing more than part of the orthodoxy known as science. Other beliefs are just as valid, and they deserve equal time because anything less is unfair.

There is only one thing wrong with this viewpoint. Evolution is not a belief. Even though nobody is ever going to see birds evolving from dinosaurs, evolution does not rest on the same sort of faith as, say, belief in an afterlife. You might as well say you believe in stars or electrons because you, personally, have never seen great flaming balls of gas or infinitesimal blips zipping by. Switching on a lamp or a computer doesn’t feel like an act of faith. (Well, maybe just a little bit, in the case of computers.) The physical world isn’t something to believe in. It’s just there. Likewise, believing in science would be like believing in a yardstick. It’s just a way of studying that world.

Science is defined by a method, and that method explicitly involves only measurable objects and testable predictions whose results can be independently verified. That means science doesn’t work on anything that can’t be measured and verified. It does *not* mean that everything immeasurable is unimportant. Quite the contrary, since love, joy, hate, hope, beauty, and God are all beyond measurement. Science doesn’t have the tools to tell us anything about them.

What science can tell us about is the physical world, and it is so effective in its own limited range that it’s given us vast power. This has a whole slew of unscientific consequences. Humans, as a matter of observable fact, adore power, so science has acquired a mantle of god-like authority that doesn’t remotely fit. Scientists, who are human beings in their spare time, tend to like the authority and all the perks that go with it, and they’ve certainly come up with their own share of stupid orthodoxies. But that has nothing to do with science itself. Science is not, and by its nature cannot be, a belief system any more than carpentry could be.

So where does that leave evolution? It’s called the Theory of Evolution, and in order to understand what that means one has to understand how scientists use language. Truth is immeasurable, so science can’t find truth. It doesn’t try to. It talks only about the likelihood that a given result will be observed again.

All scientific conclusions are probability statements: an observation is repeated a number of times and, say, nine times out of ten the results confirm a given idea, so . . . the idea is thrown out. A ninety percent chance of being right is not good enough. The probability of being right has to be nineteen out of twenty in the biological sciences. It has to approach ninety nine out of a hundred in the physical sciences. Imagine applying those standards in your personal life.

In science, that’s just the beginning. The hypothesis, which is an expensive word for educated guess, is merely said to be confirmed once it passes that bar. These guesses are dignified with the name of “theory” when they have been confirmed so many times there is no real chance they won’t continue being confirmed. They are called “laws” when that certainty becomes crushing, but even laws are probability statements. The law of gravity is a probability statement with an extraordinarily low chance of not working.

Against that backdrop, evolution is called a theory because there are so many facts in its favor. It’s a parallel case to our understanding of stars and electrons. We have no personal experience of any of them, but scientists who have studied the facts have come up with coherent explanations that pan out. Evolution can explain practical things, such as how bacteria develop antibiotic resistance and why measles epidemics run in cycles, and it can provide mind-altering insights such as that insects and mammals have the same basic body plan, except the plan is back to front.

None of the other ideas for explaining the patterns of life rests on any facts that contradict evolution. The theory of intelligent design (and “theory” is used here in its common meaning) has not been able to show the existence of intelligence in the design, using scientific methods. Creationists can’t show that creation occurred. If the scientific method is not used, the result is not science.

People who argue against evolution can, and do, fit some of the facts into their theories, but they have to ignore all the facts that disagree, which is about as far from the scientific method as you can get. They have no measurable observations and no testable, independently verifiable predictions.

Intelligent design and creationism, by those or any other names, are not competing scientific theories. They are simply theories. They may deserve equal time, but only with their equals in the realm of ideas. Discussing intelligent design in a class on evolution is like considering theories on good government when building a rocket ship.

At the heart of the problem lies confusion about science and religion. Both may have authority and try to explain the world, but the worlds they’re trying to explain are different, the way they explain things is different, and their authority rests on different foundations. Science is not, *and cannot be*, in conflict with religion because they address fundamentally different questions. Facts can certainly contradict specific scriptures, because God’s stenographers do suffer the occasional hiccup, but that doesn’t mean science can suddenly answer cosmic questions about the reason for our existence, or that religion becomes a good way to cure AIDS.

Using religion, or anything else for that matter, to argue against facts is a hopeless endeavor. You can’t argue with facts any more than you can believe in them. And evolution is as close to a fact as biology gets. In Bill Bryson’s inimitable words, denying evolution proves conclusively that the danger for those who try it is not that they may be descended from apes but that they may be overtaken by them.

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