Counterarguments to Common Christian Arguments

Evolution is only a Theory

                I commonly hear Christians saying, "Evolution is only a theory." By extension, I often hear, "Evolution isn't proven" and "science could have it wrong again." While people who say these things are technically correct—the theory of evolution is a theory and not "proven," as science cannot "prove" anything—these people are most often mistaken in that they believe that the current scientific understanding of the origins of life could be, or is, completely incorrect rather than incomplete or partially incorrect.

Foremost, we must understand what a "theory" is. People who spew the rhetoric above generally think that a theory is merely an idea that has yet to be "proven." However, the definition of a theory is, "a supposition or a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained."

Let's first unpack the initial definition: a system of ideas intended to explain something. This means that I could state something that is a known fact—for example, gravity is responsible for the earth orbiting the sun—and this fact is considered a theory, a system of ideas intended to explain something. So the word "theory" does nothing to discredit the reality of the theory of evolution. Are all theories factual? Of course not; that's why ufologists create what are known as "conspiracy theories."

Next, we'll look at the second part of the definition: especially one [a system of ideas] based on general principles independent of the thing to be explained. In other words, most theories—such as the theory of evolution—use known facts to connect the dots and explain something. Whether the theory is true, the facts remain true independent of the theory; the more facts are supporting the theory, the more valid the theory is. The theory of evolution is one based on underlying principles, such as: animals are capable of biological adaptation, and that all known living things share vast amounts of identical DNA (for instance, the DNA of humans and chimpanzees is about 93% identical, and humans share slightly less than 5% of their DNA with bananas). Even if a you don't accept the theory of evolution, those two facts—that animals are capable of biological adaption, and that all living things share DNA—remain true.

Now that we understand that the word "theory" alone does not diminish the validity of a proposed system of ideas, we can tackle the next creationist opposition: "Scientific theories have been wrong in the past, so what's to say science doesn't have it all wrong again?"

Science is constantly expanding as we make more discoveries, and our understanding of reality is always incomplete. However, it's quite safe to say that our current understanding of reality is the best understanding humans have ever had, given the amount of past discoveries we have to work off of and the technology at our disposal. Additionally, peer review within the scientific community is more rigorous than it ever was previously. I've heard creationists cite examples such as the Ptolemaic view of the solar system or the phlogiston theory, both outdated and wildly inaccurate theories. However, you'd be hard-pressed to find a similar example from the past 200 years—there is not a single modern example of a scientific theory that was both false and widely accepted by the scientific community. It's true that science is always incomplete, but thanks to historical experience, technology, and peer review, it's extremely unlikely that a completely false scientific theory will ever be accepted by the world at large.

I hear many creationists upset that the theory of evolution is presented in text books and other publications as a known fact when it is only a theory. However, now that we understand what a theory is and why it's unlikely for any widely accepted scientific theory to be false rather than incomplete, you can see that the current scientific understanding of reality is always presented as fact—as it should be! In time all theories will be revised as our understanding of the Universe increases, but that doesn't mean that scientists should not present their understanding as if it is factual. It's important to remember that theories are always presented as fact—through every scientific era and every theory, this has been true.