Logical Fallacies: Argument from Incredulity

Have you ever played the classic icebreaker game “two truths and a lie”? In each round, one person lists three statements about themselves, only two of which are true. The other person’s job is to guess which statement is incorrect. For example, here are two truths and a lie about me:

Statement 1: I was born in Canada’s subarctic.

Statement 2: I grew up on a dairy farm in western Canada.

Statement 3: My first car was a hatchback that I helped to paint neon green.

Naturally, a little psychology goes into formulating your statements. Do you make them sound equally believable so that people truly have to guess which one is right? Do you pair a mundane sounding lie, which seems easy to believe, with an extraordinary truth, which seems harder to believe? Or, if you think people expect you to give a far-fetched truth, do you provide mundane-sounding facts instead?

Truth and Believability

Within a few rounds of the game, you’ll probably notice something important: a message’s believability does not always correspond to its truth. Sometimes, true messages may seem difficult to believe, while false messages appear all too believable. So, stating a message is false simply because it may be difficult to believe, imagine, or understand involves a type of flawed logic called the argument from incredulity fallacy.

For example, somebody might argue, “The Bible’s teachings can’t possibly be true. I can’t imagine how one God could be three Persons at the same time. I don’t see how Jesus could have literally been God in human flesh—much less, born of a virgin. Do you really expect me to believe all that?”

We can catch the fallacies in this example by applying the critical thinking hack of asking, “Is this message true or false because . . . ?” Here, we’d ask, “Are the Bible’s teachings false because . . . someone finds them difficult to understand?” Worded this way, it’s easier to see the answer is no.

Avoiding Arguments from Incredulity

As another example, I’ve read evolutionists write that creationists can make arguments from incredulity when describing the many problems with evolution. For instance, a creationist might point out, “It’s difficult to fathom how mechanisms like mutation could produce complex new structures.” To this, an evolutionist could easily respond, “Just because you find it difficult to fathom doesn’t mean it didn’t happen.”

True. Arguing against evolution simply by pointing out that evolution is difficult to imagine without providing further premises would be a fallacy. Of course, the fact that people may try using fallacies to argue against unbiblical principles does not affect the Bible’s truth. (See Don’t Creationists Use Logical Fallacies?) However, to credibly defend our biblical worldviews, we’re responsible for keeping our logic as fallacy-free as we know how—including by avoiding arguments from incredulity.

In this case, we can avoid arguing from incredulity by showing why evolutionary scenarios are hard to imagine: not because we lack imagination, but because what we know from observational science is inconsistent with the idea life in all its forms could have arisen naturally. (For more information, check out articles on information theory, life’s origins, mutation, and natural selection.)

Summing Up

To be fair, there’s nothing wrong with pointing out that an idea seems difficult to believe. The trouble comes when we list this difficulty as our only reason for rejecting an idea without offering logical statements to support why the idea is unbelievable. Providing those statements allows us to avoid arguments from incredulity so that we can communicate the truth in (logically valid) love.

Speaking of truth—did you figure out the answer to my two truths and a lie riddle?

Here it is:

I really am from Canada’s Northwest Territories. I did live in Western Canada—but not on a dairy farm. And the bit about painting my first car neon green? That was true.

Believe it or not.