Why Is Evolution so Widely Believed?

Author Tim Barnett Published on 07/15/2015

A common question that comes up after I give my talk titled Why I Am Not an Evolutionist is, “If there are so many good scientific arguments against evolution, why is it so widely believed?”

I recently came across an article by Dr. William Lane Craig where he responds to this exact question. In his brilliant response he makes two key observations, which I will highlight here.

First, Dr. Craig points outs that the mainstream acceptance of the theory of evolution is not for scientific reasons; it’s accepted for philosophical reasons. More specifically, it’s believed because of a commitment to methodological naturalism. Craig says:

I think the short answer is that it’s the best naturalistic theory we’ve got. If, as a result of methodological naturalism, the pool of live explanatory options is limited to naturalistic hypotheses, then, at least until recently, the neo-Darwinian theory of biological evolution driven by the mechanisms of genetic mutation and natural selection was, as Alvin Plantinga puts it, “the only game in town.” [Emphasis mine.]

Methodological naturalism simply means that scientists must assume philosophical naturalism—only natural causes exist—when doing science. Of course, this assumption excludes all supernatural explanations a priori. Therefore, for anyone holding to methodological naturalism, creationism and intelligent design are not on the table as possible explanations. Even if all the scientific evidence pointed away from evolution and towards intelligent design, they would still need to cling to the theory of evolution because it’s the only possible naturalistic explanation. It’s the only game in town.

Second, Craig offers a helpful reminder. He says, “It’s helpful to remind ourselves that the word ‘evolution’ is an accordion word that can be expanded or contracted to suit the occasion.”

Evolution is an equivocal word. This means that it can have more than one meaning. For instance, it can mean anything from simple, biological change over time—change in allele frequency—to universal, common descent of all organisms from a single, common ancestor. The former is accepted by virtually everyone, including the staunchest young earth creationist. The latter, on the other hand, has many highly qualified biologists questioning whether the mechanism of natural selection acting on random mutations is up to the task.

So when the question arises as to why evolution is so widely believed, we need to find out what the questioner means by evolution. In one sense, evolution is believed because it’s true; organisms change over time. In another sense, it’s believed because it’s the only theory in play given their commitment to methodological naturalism.

Craig concludes:

So while evolution in an innocuous sense is well-established, belief in evolution in [other senses] is not universal among scientists, and the dominance of neo-Darwinism heretofore is due to the constraints of methodological naturalism and the want of a better naturalistic alternative.