The word “evolution” can mean several different things, depending on the context.  But in conversations about creation, human origins, science and religion, etc., however, it has a far more precise definition. As National Geographic points out, “evolution is a shortened form of the term ‘theory of evolution by natural selection,’ which was proposed by Charles Darwin and Alfred Russel Wallace in the nineteenth century.”¹https://www.nationalgeographic.org/encyclopedia/theory-evolution/ (accessed 01/18/2021) Thus, the term is a concise way of referring to, in the words of one microbiologist, “a process whereby life arose from non-living matter and subsequently developed entirely by natural means.”²Michael Behe, Darwin’s Black Box (The Free Press, 1996) xi Yet, the fact that evolution can mean other things sometimes leads to confusion. In particular, one rhetorical strategy used by some defenders of Darwinian evolution is to switch to a broad definition of “evolution,” most popularly the simple phrase “change over time,” and then argue that, since everyone agrees that there is “change over time,” the Darwinian theory of Evolution is an incontrovertible fact that must be accepted by all.

This is the logical fallacy of “equivocation,” i.e., using a word with more than one meaning and switching meanings in the middle of your argument to make the argument work. In this case, starting with generic evolution (change over time) and then switching to Darwinian Evolution (a specific biological theory about the origins and history of all life on earth) leads to a false conclusion. Just because things change over time does not mean that all varieties of life gradually descended from a common microbial ancestor through strictly natural processes. There is no logical connection. It is merely an accident of words.

An example of the “change over time” argument

To show what I’m talking about, let’s take a look an example from the writings of paleoanthropologist and Harvard professor Dr. Daniel Lieberman, who writes:

“evolution elicits equally strong opinions from those who study it professionally and those who consider it so wrong and dangerous that they believe the subject shouldn’t be taught to children. Yet, despite much controversy and passionate ignorance, the idea that evolution occurs should not be contentious. Evolution is simply change over time. Even die-hard creationists recognize that the earth and its species have not always been the same.”³Daniel Lieberman, The Story of the Human Body (Knopf Doubleday Publishing Group, 2013) 8

This is just verbal sleight of hand. In context, the “evolution” that elicits strong opinions from creationists, the evolution that is studied professionally and is the subject of Lieberman’s book (which is about mankind’s physical descent from a chimp-like ancestor,) is not merely “change over time.” The fact that even “the most die-hard creationist” completely agrees that things change over time in no way compels them to agree that all life on earth is the purposeless product of blind, material processes or that all life descended by chance and impersonal law from an ancient proto-bacterium. The one point has no logical connection to the other. It’s two different definitions of the word!

It would be like arguing that, since everyone knows that the opposite of right is wrong, it should be no controversy to say that anyone who doesn’t hold their pen in their right hand is using the wrong hand! Left handed people are thus morally inferior, and we all know it, right? Obviously not. It’s sophistry, a clever but deceitful twisting of words. Dr. Lieberman is a highly intelligent man, and so it is difficult to imagine that he doesn’t realize what he is doing. While this kind of wordplay may occasionally trip up opponents of Darwinian theory, it hardly represents a genuine attempt to advance the conversation and move people toward an intellectually honest and informed consensus on the subject. This kind of argument is, at best, only a distraction from getting people to discuss the real issues.

Arguing with the Dictionary

We see this fallacy repeated only a few pages later in Dr. Lieberman’s book when he interacts with a dictionary definition of “evolution:”

“Do you think that evolution is just the study of the past? I used to, and so does my dictionary, which defines evolution as ‘the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth.’ I am dissatisfied with this definition because evolution (which I prefer to define as change over time) is also a dynamic process that is still occurring today.”⁴Ibid, 19

It is fair to note that Lieberman’s criticism of this dictionary definition is actually valid. While the Darwinian theory of evolution is primarily concerned with explaining the past development of life into its current state, the theory describes a process that, if true, would certainly still be at work in the world today. Thus, to define the biological theory of evolution only in reference to the history of past ages is not entirely accurate. Dr. Lieberman is right to object.

Yet, in his objection, he again offers the generic “change over time” as a better definition. This is simply false. While we do more generally speak of the “evolution of the automotive industry” or the “evolution of military strategy,” and this refers merely to changes over time, that is not what people mean by “evolution” when they are discussing biology and human origins. Even in Lieberman’s book, when he later argues that evolution should include “cultural” evolution, he means cultural causes of biological changes. He acknowledges that some of the changes in the human body over time have happened because of things like the innovation of agriculture or the industrial revolution and that such culturally-influenced changes in the body are part of evolutionary biology, this is still defining evolution specifically in terms of physical changes in the traits of organisms on a chain of hereditary descent, not all broadly generic “change over time.”

Is a rusty car in a junkyard a triumph of Darwinian theory? After all, the car was not always rusty, nor was it always in a junkyard. It has changed over time. Does that prove Darwin correct that every form of life on earth descended from a simple common ancestor through random variation and natural selection? Obviously not! The mere existence of change over time does not prove or disprove Darwinian evolution. They are unrelated. It is two different definitions of the word. Dr. Lieberman may well have a valid complaint against some dictionaries, but his solution of offering an even less adequate definition of the word makes matters worse, not better.

Conclusion

The point here is not to pick on Daniel Lieberman. He is an intelligent scholar, and while I do not share his worldview, his research has often genuinely helped me better understand the mainstream Darwinian view of human evolution (and some of the variations within secular scholarship on the subject). I cite him here merely as one clear and convenient example of a much wider problem that shows up frequently in discussions on this topic. If we are to meaningfully discuss the issue of Darwinian Evolution, it is important that we all understand the basic terms of the debate. Muddying the water with rhetorical tricks and equivocation fallacies, whatever one’s intentions may be, only makes an already contentious conversation that much harder. If our goal is the truth, our methods of debate must be truthful. In this debate, “evolution” does not simply mean “change over time.” It is shorthand for a specific, detailed theory in biology, and one with which most Christians take issue on a number of key points. That is where the conversation should focus.