“But Mom, all my friends do it!” “Everyone’s switching to Right Guard!” “No one believes that anymore!” You have probably heard a child, advertiser, or friend say these things before. It may have initial appeal, but when you stop and think about it you know something is wrong with this line of thinking. These are all examples of another common logical fallacy: the “bandwagon fallacy” (or the “appeal to common practice” and the “appeal to populace” fallacies). This is a fifth way healthy discussions are shut down.

Some Common Examples

This fallacy is so intuitive our children use it without thinking. There isn’t a parent alive who hasn’t heard a child argue that his or her friends are all doing something questionable, so they should be allowed to do so too. Whether it is a movie they want to see, an hour they want to stay out until, or a place they want to go, the argument is that it must be alright since all their friends are doing it. All the other parents are on the “bandwagon,” so what’s wrong with you?

Of course, we easily spot this fallacy of reasoning when our children employ it. But it is often harder to spot when a friend, colleague, boss, advertiser, or media personality use this same fallacious type of argument. Why is that?

One reason is that we experience this fallacy so often in our culture that we become immune to it. Depending on how much TV or radio we listen to, we likely hear it many times a day, as this fallacy underlies much advertising. If you can be convinced that everyone else is now using a certain product, you will be inclined to “get with it” and start using the product too. In other words, everyone has already “jumped on the bandwagon” so why haven’t you switched yet?

Social media fuels this fallacy each day as well. Someone posts a view endorsing a person or idea (or conversely, disagreeing with an idea or person). Then everyone else “likes” the post. So we assume the view expressed must be right and we “like” it too. After all, since everyone else thinks the idea or person is good (or bad), it must be true. We want to hop on the bandwagon!

Unfortunately, even teachers and professors sometimes employ this fallacy when students don’t agree with their point of view. A professor of mine in graduate school believed we are nothing but “matter in motion”—highly evolved machines. I challenged his view with evidence for Substance Dualism (the view that we are composed of a body and a soul.) I offered a number of arguments for my view (some of which I discussed here and are articulated at the highest academic level in, for instance, the Blackwell Companion to Substance Dualism). He didn’t respond to my arguments. Instead he just said, “That’s pre-Enlightenment thinking—no one still holds to that view!” In other words, everyone else is on the Enlightenment’s materialist “bandwagon,” so why don’t I get on board too?

Examples When Discussing Spiritual Matters

Not unexpectedly, we often encounter this fallacy when discussing spiritual truths with someone. For instance, you may share that because Jesus claimed to be God and proved this by his resurrection, he is the only way to salvation (as I argued here.) Your friend quickly responds with, “No one believes that anymore!”

Or you may be sharing reasons you believe the Bible to be God’s inspired Word (as I argued here). Your friend replies, “That’s what they used to believe back before electricity! Come on, get with the program!”

Or you may be sharing there are good reasons to believe in moral absolutes (as I argued here).  To this your professor responds, “Everyone knows that is nonsense!”

What Is The Error In Logic?

So what’s going on here? It all boils down to people not thinking clearly about whether the premises, leading to this conclusion, are true. Yet the informal nature of the conversation often masks this, and so this jump in logic is missed.

The argument can be put formally this way:

                Premise 1: All X believe Y

                Premise 2: If all X believe Y, Y must be true

                Conclusion: Therefore, Y is true 

Putting it this way, problems with both the first and second premise become clear. In the rest of this post I’ll do the “spadework” to show logically why these two premises are false. Next week I’ll provide examples of how to get a conversation back on track by helping a person caught in this fallacy see where he has gone wrong.

                First Premise: False!

The first premise claims that everyone believes X (or some variation: every reasonable person, every enlightened person, every knowledgeable person, and so on).

But is this true? Almost always not. This is a problem with any claim of “all” and similar universal proclamations (“only,” “always,” “every”). Just one counterexample falsifies the claim—shows the premise is false. It is usually not too hard to find one (and often more) counterexamples—people who do not believe Y (including reasonable persons, “enlightened” persons, knowledgeable persons, etc.)

Without a true premise, we do not have a proven conclusion (as discussed here). Therefore, it is irrational for a person to accept the conclusion. Y is not shown to be true, as assumed.

                Second Premise: Also False!

The second premise is equally fallacious. Even if everyone believes it is true, why does someone think this makes it true? Evidence makes a claim true or false, not the number of people who believe it. In other words, truth is determined by evidence, not popular vote.

In fact, there are many cases of everyone believing someone that was clearly false. For instance, in many ancient cultures, and some to this day, “everyone” believed women are of less value than men. Does that make it true? No. Those who believe this are simply wrong.

Similarly, in many cultures and for many years it was believed that a person’s value was based on his or her ethnicity. Did that make this view right? Not in the least.

For a third example, over a period of many years everyone believed the earth was flat. So was it so? Obviously not.

These and other counter-examples proved the second premise is false: just because everyone believes something does not mean it is true. (A fictionalized example which makes this point very well is the children’s book The Emperor’s New Clothes.)

Moral reformers are often the ones who see this before others do. For instance, Ghandi, Martin Luther King, and Jesus himself all identified wrong beliefs about Untouchables, African Americans, and women respectively. But they didn’t assume that “since everyone believes they are second-class citizens, it must be true.” Rather, they stood against the prevailing consensus and said, “You all believe this, but you are all wrong!” They refused to accept premise two. And we are all better as a result of their courage to go against the cultural tide of their day!

So now we have not one but two false premises, and so the conclusion is doubly falsified! Anyone seeking to be reasonable, rational, and discover truth in a discussion will quickly agree that he cannot believe Y simply because, “everyone believes it.”

Conclusion

So once we spot this fallacy at work, how do we point it out and get the conversation back on track? I’ll share several strategies next week. Until then, grace and peace.

For further reading, see Norman L. Geisler and Ronald M. Brooks’ Come, Let Us Reason: An Introduction to Logical Thinking.