Evolution is a poor test for rationality

In my last post, I presented three questions I’ve heard young people ask–people who think highly of Jesus and even seem to want to become Christians and follow Him, but worry they can’t without sacrificing their rationality, their decency, or both.

The first question is: Can I be a Christian and still believe in evolution? They seem to be reasoning that rational people accept evolution, but Christians don’t accept evolution, and so Christians are not rational.

As I explained in my last post, Christians can accept evolution, and many do. But there’s another problem with this reasoning. Many people have the idea that you must accept evolution if you’re a reasonable person who has been properly informed of the evidence for it–that acceptance of evolution is a test for rationality.

But evolution is a very poor test of rationality. Let me explain.

This jacaranda tree has nothing to do with the topic of this post. But it’s very pretty, isn’t it?


You should know two things.

First, you should know that, in academic society, it is generally considered unacceptable to reject evolution.  Generally, in the academic circles I’ve traveled across America (admittedly, not that many), it is simply assumed that rational and well educated folk are evolutionists.

Second, you should also know that it is acceptable in academic society to be a theistic evolutionist. You can think God created life and still be considered rational, just as long as you think God used evolution to do it.

Now, one more bit of preliminary observation, and then in the next paragraphs I will finally get to the point. The case for evolution, like the case for most theories in science, is cumulative; you don’t argue for it from a single piece of evidence; you argue that it is the best explanation of several different pieces of evidence. Now the evidence for evolution can be divided into two main categories. There is the evidence that life evolved, and there is the evidence that natural processes are sufficient to account for life on earth as we know it today. The first kind of evidence only supports the claim that it happened, while the second kind of evidence supports the claim that it happened in a certain way, that is, by natural causes. The first kind of evidence includes, but is not limited to, the fossil record. The second kind of evidence would include, for example, instances of natural selection at work creating changes in a species.

But therein lies the problem. A theistic evolutionist can believe that God, not natural processes alone, is responsible for the emergence of life on earth as we know it today. In other words, the entire second category of evidence for evolution has not convinced him. (Or else his doctrine of creation has an odd deistic region, since he thinks natural causes acted without guidance from God to create the species on earth today.)

But this leaves him with just the one category of evidence, which on its own is much less powerful than would be the evidence taken as a whole. His confidence in evolution is (or should be) proportionate to the evidence that it happened, not proportionate to the entire cumulative case for the theory of evolution.

These matters should really be discussed over tea.


To sum up: Theistic evolution is thought to be rational. But this means it is rational to reject one category of evidence for evolution, and this means that rejecting evolution itself is rational–or at least it is somewhat less irrational than is commonly thought.

To put it differently: If it really is rational to accept theistic evolution, then, since the evidence for evolution includes a category of evidence which does not convince a theistic evolution, it is rational to reject the overall conclusion that this evidence is supposed to support–or at least is less irrational than is commonly thought.

To put it still differently: If some people can rationally reject the second category of evidence for evolution, I don’t see why other people should automatically be considered irrational just because they aren’t convinced by the evidence that remains.

And if people who reject the theory of evolution altogether are irrational, then so are all the theistic evolutionists who reject one of the categories of evidence for evolution–or at least they are less rational than is commonly thought.


To sum up this post and my last post:

There are three big questions that keep people away from Christianity.

Question 1 is:

Can I be a Christian and still believe in evolution?

And the answer is:

Yes. (But you don’t have to.)

Questions 2 and 3 to be addressed in future posts.

(More articles at www.ThinkingThroughChristianity.com)
12 Comments

Add a Comment

Your email address will not be published. Required fields are marked *