Glenn Branch's picture

What’s Wrong with “Belief in Evolution”? Part 1

Rodin, The Thinker. Photograph: Frank Kovalchek, via Wikimedia Commons.Over at the PLOS Sci-Ed blog, Adam Blankenblicker recently reported, “I asked one of my colleagues at work, Dr. Briana Pobiner, a paleoanthropologist, ‘You believe in evolution, right?’ I was surprised by how quickly she answered ‘I don’t believe in evolution—I accept the evidence for evolution.’”

I’m not surprised. Talk about belief in evolution is often associated with skepticism about evolution. Think about, for example, the odious phrase, “Some scientists believe,” which occasionally is seen in textbooks as a preface to “... that all living organisms on earth share a common ancestry” and the like.

Additionally but less conspicuously, talk about belief in evolution is also often associated with outright rejection of evolution. “You believe in evolution?” asks the creationist, with a sneer. “Well, that’s just your belief.” Creationists often like to raise creationism to the level of a science, but they also often like to lower evolution to the level of a belief.

So Pobiner’s speedy response is understandable. And I think that she’s right to stress that she accepts the evidence for evolution. But—perhaps surprisingly—I think that she’s wrong to say that she doesn’t believe in evolution. I suspect she’s in the grip of a false theory about the meaning of “belief.”

She’s not alone. A lot of people overreact to talk about belief in evolution—understandably, given how pernicious talk about belief in evolution can be. And their overreactions often take the form of a false theory about language, whether about the meaning of belief or about the use of the term.

One form of overreaction is denial: e.g., the claim that “belief” is not a word used in science. (I’ve often heard and occasionally seen the claim; if you know of a printed source, please leave a comment or drop me a line with the reference.) But it’s easy to show that the claim is mistaken. In the sixth edition of the Origin, Darwin wrote:

As a record of a former state of things, I have retained in the foregoing paragraphs, and elsewhere, several sentences which imply that naturalists believe in the separate creation of each species; and I have been much censured for having thus expressed myself. But undoubtedly this was the general belief when the first edition of the present work appeared. I formerly spoke to very many naturalists on the subject of evolution, and never once met with any sympathetic agreement. It is probable that some did then believe in evolution, but they were either silent, or expressed themselves so ambiguously that it was not easy to understand their meaning. ... Under a scientific point of view, and as leading to further investigation, but little advantage is gained by believing that new forms are suddenly developed in an inexplicable manner from old and widely different forms, over the old belief in the creation of species from the dust of the earth. (emphasis added)

Similarly for “belief in,” from a letter Darwin wrote in 1861:

I believe in Nat. Selection, not because, I can prove in any single case that it has changed one species into another, but because it groups & explains well (as it seems to me) a host of facts in classification, embryology, morphology, rudimentary organs, geological succession & Distribution. (emphasis added)

I picked Darwin as a sentimental favorite, of course. But it wouldn’t be hard to multiply examples of scientists using “belief” and “belief in” without compunction in today’s scientific literature, as Mark Liberman, a professor of linguistics at the University of Pennsylvania, told the Philadelphia Inquirer’s Faye Flam in 2011.

A second form of overreaction involves making dubious claims about the meaning of “belief.”  Here, for example, is Mike U. Smith, writing in the Journal of Research in Science Teaching in 1994, making the claim that “belief” is systematically ambiguous between ordinary and scientific meanings:

Belief is one of those troublesome terms that has different meanings for the scientist and the common man. For example, the scientist who says “I believe in evolution” clearly has a different meaning in mind from the lay person who says “I believe in God” or “I believe that the earth is flat.” ... Whenever a scientist uses the term belief in conversation, clearly he is referring to something that is well grounded in evidence.

Smith offers no evidence for the claimed ambiguity of “belief”; although he cites a dictionary definition of the word, there’s no indication in it of a special scientific meaning as opposed to a lay meaning. I checked the Oxford English Dictionary, and there’s no trace of Smith’s ambiguity in it either.

Dictionaries aren’t infallible, of course. I note with amusement that the Merriam-Webster dictionary on-line seems to think that “evolution” applies only to plants and animals: tough luck for all the rest of the eukaryota, to say nothing of the archaea and the bacteria. But missing the systematic ambiguity of a common term like “belief” is unlikely.

So is there no explanation of why it’s problematic to talk about belief in evolution? Is it just a feature of the conceptual landscape that we have to recognize and navigate around without having any understanding of its origin? No: there is a good explanation. And that will be the topic of part two of “What’s wrong with “belief in evolution’?”