Is Evolution Religion?

I received the following interesting and thoughtful letter from a retired physician, whom I shall call Dr. S. I have not received permission to publish Dr. S’s letter verbatim, so I will paraphrase it:

Dr. S says he was “raised a Christian but didn’t have it shoved down [his] throat.” He majored in biology and chemistry in college and had a year of biochemistry in medical school. He takes evolution “as a given.”

Dr. S recently read a magazine article defending evolution against intelligent design and also mentions the new book Why Intelligent Design Fails. He asks if we are making a mistake and doing poor science. True scientists, he suggests, would “question the theory of evolution to make sure it’s not just another crackpot idea that has gained wide acceptance.”

Indeed, by defending evolution are we not lowering it from science to religious dogma? Has the theory of evolution become “an anti-religion religion”?

Dr. S thinks we should encourage intelligent design and calls it “a graceful way for Christians and Jews to evolve away from the Old Testament story of creation which is probably a total crock.”

Dr. S raises good points and probably shares his qualms with a great many observers. I will therefore answer him here.

First, Dr. S’s implicit assumption is that intelligent-design creationism is a religion. It is not. It may be religiously motivated, but it is not in itself a religion. It is a pseudoscience and needs to be fought like all pseudosciences. I doubt that Dr. S would demur if some medical practitioners spent their time exposing homeopathy or therapeutic touch as quackery, nor would he fear that the practitioners who did so were somehow making a mistake and turning medicine into an anti-quackery quackery. In the same way, we are by no means turning science into religion by defending evolution against intelligent-design creationism. Indeed, the book, Why Intelligent Design Fails, which I coedited with Taner Edis, attacks intelligent-design creationism on its scientific merits (or lack thereof) and barely mentions religion, except in a historical introduction.

Wouldn’t true scientists question the theory of evolution to make sure it’s not some crackpot idea? Of course: evolutionary biologists probably do so implicitly every time they perform an experiment or interpret a data set.

Theory is technical term in science - a term of art, or a word that has a very specific meaning in a given field - and emphatically does not mean a hunch or a speculation. My American Heritage Dictionary gives the following definitions of “theory”:

1.a. Systematically organized knowledge applicable in a relatively wide variety of circumstances, especially a system of assumptions, accepted principles, and rules of procedure devised to analyze, predict, or otherwise explain the nature or behavior of a specified set of phenomena. … 2. … speculation. … 4. An assumption based on limited information or knowledge; a conjecture.

The theory of evolution is a theory in sense 1.a, not 2 or 4, which are more colloquial uses of the term; Dr. S may be using “theory” in senses 2 or 4. No theory in science is ever a crackpot idea that has gained wide acceptance, inasmuch as a theory has to be tested over and over before it is accepted as a full-fledged theory. Indeed, it is unfortunate, in a way, that scientists speak of the theory of evolution, rather than the law of evolution. Perhaps it is our humility that gets in the way of public understanding. But in fact the use of theory here is very close to law, as in the law of gravity.

Evolutionary biology is based on the observed fact of common descent. “Everyone” knew the fact of common descent in Darwin’s day. Lamarck’s theory of inheritance of acquired characteristics was an attempt to account for common descent; it foundered on its lack of a mechanism and on the noninheritance of many acquired characteristics. Darwin and Wallace accounted for common descent by developing a theory that included natural selection, but additional mechanisms have since been identified. The fossil record, the genetic code, and a body of mathematical inference all contribute to the modern theory of evolutionary biology.

Let me give an analogy from Dr. S’s own field: the germ theory of disease (my colleague Tara Smith will have more to say about this theory shortly). The germ theory of disease was an attempt to explain the fact that many diseases are infectious. It has been well established by observation and laboratory experiment. If we count viruses as germs, then the vast majority of diseases are caused by germs. You would frankly have to be nuts to deny the germ theory. Even ulcers have been shown to be caused by germs, though there is still controversy whether stress is an additional factor.

Not all diseases are infectious. Depending what you count as a disease, schizophrenia, hayfever, scurvy, cancer, and diabetes are presumably not infectious (though it is possible that certain diseases that are not considered infectious nevertheless have infection as a component). Mad-cow disease, by contrast, is caused by an infectious agent that is not alive and hence not a germ. The germ theory of disease is by no means undermined by such observations; we simply conclude that we have more work to do, and the germ theory is subsumed by a more-general theory that includes deficiencies, genetics, and environmental agents.

In the same way, Darwin and Wallace’s theory was subsumed by a more-general theory that is sometimes called the modern synthesis.

Is evolutionary biology (the modern synthesis) a dogma? No, no more than the law of gravity. Is it an anti-religion religion? No. Evolutionary biology says nothing whatsoever about God. It says that we can adequately explain the observed fact of descent with modification without invoking God or a creator, but it by no means denies the existence of a creator. Some biologists think that evolutionary biology provides evidence against the existence of God, just as some think it allows for a god. I think you may with intellectual honesty believe anything you like regarding God, provided that your belief does not contradict known scientific fact.

I don’t know whether I would call the Hebrew Bible’s creation story a crock, though it is certainly not historically accurate. But then I do not expect poetry to be accurate and never really believed the ancient mariner or the traveler from the antique land either. Can intelligent-design creationism substitute for Biblical literalism, as Dr. S suggests?

Here I think Dr. S is partly on the right track. Theistic evolutionists believe in intelligent design in a broad sense, and they believe that God created the universe. They do not deny evolutionary biology, however, but rather argue that evolution was God’s way of creating intelligent life. I would be very pleased to see theistic evolution make inroads against Biblical literalism.

But theistic evolutionists are not intelligent-design creationists in the common meaning of the phrase. What is conventionally called intelligent-design creationism is profoundly anti-scientific in that it introduces God (or perhaps some other creator) into the mixture precisely where we should be looking for natural mechanisms. Additionally, people who hold one anti-scientific view are apt to hold two; some evolution deniers, for example, also hold the dangerous view that HIV does not cause AIDS. Finally, intelligent-design creationists advocate teaching their pseudoscience alongside real science in the public schools; this tactic is a thinly veiled attempt to inject religion into the classroom and can only be divisive. Intelligent-design creationism is not a benign substitute for Biblical literalism.

Note added 28 July 2005: Tara Smith’s article, “Why isn’t the germ theory a “religion”?” may be found at