Post Author: Bill Pratt
One of the first things I was taught in my seminary classes was to carefully define terms and concepts before launching into a debate over them. So many times, when I see two people arguing about a topic, they are using different definitions for the same words. It’s impossible to have a productive discussion with someone when you don’t agree on how to define terms.
Recently I read a great article in the Christian Research Journal (Vol. 35 / No. 1 / 2012), written by Jay Richards, on the topic of evolution and its varying definitions. The article is entitled “Thinking Clearly about God and Evolution.” I thought I would excerpt some portions of the article because I think it will be helpful to all of us when we discuss this controversial subject.
It’s a lot easier to define theism than to define evolution. It’s been called the ultimate weasel word. In an illuminating article called “The Meanings of Evolution,” Stephen Meyer and Michael Keas attempt to catch the weasel by distinguishing six different ways in which “evolution” is commonly used:
1. Change over time; history of nature; any sequence of events in nature.
2. Changes in the frequencies of alleles in the gene pool of a population.
3. Limited common descent: the idea that particular groups of organisms have descended from a common ancestor.
4. The mechanisms responsible for the change required to produce limited descent with modification, chiefly natural selection acting on random variations or mutations.
5. Universal common descent: the idea that all organisms have descended from a single common ancestor.
6. “Blind watchmaker” thesis: the idea that all organisms have descended from common ancestors solely through unguided, unintelligent, purposeless, material processes such as natural selection acting on random variations or mutations; that the mechanisms of natural selection, random variation and mutation, and perhaps other similarly naturalistic mechanisms, are completely sufficient to account for the appearance of design in living organisms.
As Christians, what are we to make of these 6 different definitions of evolution? Definitions 1-4 are almost universally accepted by young earth, old earth, and theistic evolutionists. They all agree that plant and animal populations have changed over time, that there is limited common descent, and that natural selection acting on random mutation does affect plant and animal populations.
Definition number 5 is where young earth and old earth creationists get off the boat. These folks believe that God specially created different kinds of plants and animals at specific moments in earth’s history. Old earth creationists stretch out those creative acts over some 3.5-4 billion years, whereas young earth creationists compact those creative acts into a 6-day period. In either case, it would be impossible for universal common descent to be true. Finally, theistic evolutionists would have no problem with definition 5.
Definition 6 is where even theistic evolutionists disembark. Why? Because they do not accept that evolution is “unguided, unintelligent, [and] purposeless.” God is behind evolution and He planned it out and executed on the plan through the initial conditions and physical laws that he put in place.
In part 2, I will excerpt some further insightful comments from Richards on definition 6, which is by far the most controversial definition of evolution.