False Dichotomy(Detect Extreme Views)

False dichotomy assumes that there are only two possibilities when there are more.

Frank: “Ben is conservative.”

Dan: “How do you know that?”

Frank: “Because Ben mentioned that he’s not liberal.”

If you were to hear the above conversation, you might suspect something wrong. But what is wrong in the above conversation? Frank commits an error in reasoning—a fallacy.

You can tell it’s a fallacy because even if it’s true that Ben isn’t a liberal, it still doesn’t follow that Ben is a conservative. Ben might be neither liberal nor conservative. Yet Frank overlooks this possibility. He simply assumes that if you’re not one you must be the other. That’s an error in reasoning.

That error is called a false dichotomy (it’s also known as a false dilemma, either-or fallacy, or fallacy of false alternatives). False dichotomy assumes that there are only two possibilities when there are more.

For example, Frank reasons as follows:

Premise 1: Ben is a conservative, or Ben is a liberal.

Premise 2: Ben is not a liberal.

Conclusion: Therefore, Ben is a conservative.

The problem with Frank’s reasoning is that Premise 1 is false. Liberal and conservative aren’t the only two options. Ben could be a centrist. Or Ben might not occupy any position on the political spectrum at all. Frank overlooks the possibilities. As a result, Ben’s reasoning commits an error.

False dichotomy assumes that there are only two distinct alternatives, and omits any other alternatives.

How to detect false dichotomy?

Ask yourself, can there be at least one more alternative? So the argument would look like this:

Premise 1: Ben is a conservative, or Ben is a liberal, or Ben is a centrist, or Ben occupies no position on the political spectrum at all.

Premise 2: Ben is not a liberal.

Fallacious Conclusion: Therefore, Ben is a conservative.

When we present Frank’s argument this way, we see that his conclusion doesn’t follow. What does follow is instead this:

Real Conclusion: Therefore, Ben is a conservative, or Ben is a centrist, or Ben occupies no position on the political spectrum at all.

Frank falsely assumed that there are only two possibilities, when more than two existed. He ignores those other possibilities, and as a result, his conclusion doesn’t follow.

Illustration below shows how Frank only uses two extremes of the political spectrum:

Frank only presents P1 and P5, and omits other alternatives.

P1 : Far Left

P2 : Left

P3 : Center

P4 : Right

P5 : Far Right

Examples of false dichotomy in everyday life:

Claim: Technology is either destroying society, or it's the solution to all our problems.

Explanation: This claim assumes that technology is entirely beneficial or entirely harmful. It ignores the fact that technology can have both positive and negative impacts.

Claim: You are either with us, or against us.

Explanation: The claim ignores a neutral position, partial support, etc.

Claim: Either we ban all immigration, or we open our borders.

Explanation: The claim ignores regulated immigration policies.

As you can see from the above examples, often when you encounter false dichotomy, the only two options that get presented are extremes on what is in fact a wide-ranging spectrum encompassing many alternatives between the two extremes.

Why do people fall for false dichotomies?

There are several reasons but let’s focus on two main reasons: First, most people are not trained to think beyond two possibilities. Second, most people want oversimplification, and false dichotomy is an attempt (knowingly or unknowingly) to simplify a much more complicated claim.

Caution about dichotomy vs false dichotomy

When we use the word “dichotomy,” we mean that there is a division between two things that are mutually exclusive. Not all dichotomies are false. Sometimes there really are only two possibilities. Let's look at an example where a dichotomy is true:

Premise 1: Ben is either dead or alive.

Premise 2: Ben is not dead.

Conclusion: Ben is alive.

False dichotomy is a common fallacy that is often seen in politics, marketing, and everyday conversations. Understanding what a false dichotomy will give you a tool to detect and disarm it.