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10.2: Fallacy of Irrelevant Reasons

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    If the premises of an argument are irrelevant to the conclusion, then the argument is flawed. The premises may well be true, important, and perhaps even relevant to other conclusions we care about. But if they aren’t relevant to the conclusion we are thinking about, then the argument is bad. Bad reasoning is said to be fallacious, and some bad patterns of reasoning— fallacies—occur so frequently that it is useful to give them names. This helps us to spot them and to avoid them in our own thinking.

    We commit the fallacy of irrelevant reason (or irrelevant premise) if we offer a premise to support a conclusion when the premise is irrelevant to the conclusion. Relevance is not sufficient for premises to support a conclusion, but it is necessary.

    The fallacy is also known by its Latin name, non sequitur (“it doesn’t follow”). So, when someone draws a conclusion from irrelevant premises, we say that it’s a non sequitur. The fallacy of irrelevant reasons is also sometimes called the red herring fallacy. This name is a reference to the fact that people who were fleeing from trackers with bloodhounds would sometimes wipe a dead animal across the path to throw the dogs off their trail.

    The name irrelevant reason is a sort of catch-all label. All the fallacies that we will study in this chapter have premises that are irrelevant to the conclusion. But if we have a more specific name for a fallacy (and we won’t, until we get further into this chapter), we will use the more specific label.

    Motivations behind the fallacy

    If we can’t supply relevant reasons to support a conclusion, it is tempting to bring in something that is irrelevant. This deflects attention from the fact that we don’t have good reasons for our view. This is especially effective if the irrelevant reasons have emotional impact, because these make it particularly easy to focus on things that are not relevant to the real issue.

    Sometimes responses are so irrelevant that they really don’t look like reasons at all, but they can still deflect attention from the real issue. Jokes, ridicule, sarcasm, flattery, insults, and so on can deflect attention from the point at issue. A joke can be particularly effective, since if you object that it isn’t relevant, you can then be accused of lacking a sense of humor. But you can laugh at the joke and then return to the issue.

    Safeguards

    1. Whether reasons are relevant to a conclusion depends on the conclusion and the way it is stated. So always stay focused on the conclusion.
    2. Don’t allow jokes, insults, or the like to deflect your attention from the issue. You can appreciate the joke, but then return to the point at issue.
    3. Be sure that you and the person you are talking to really are considering the same claim, rather than talking at cross purposes. If you are, try to explain your view to the other person before defending it. This doesn’t guarantee the two of you will come to an agreement, but the discussion will be more productive.

    Exercises

    1. Identify the fallacy (if any) in the first two passages.
      • R. Kelly is innocent. The charges against him are made up.
      • R. Kelly is innocent. He’s a very famous person and is a fantastic musician.
    2. Which of the following are relevant to the conclusion that we should not have laws making handguns harder to get?
      1. The Bill of Rights says that we have a right to bear arms.
      2. Many people have avoided serious injury because they had a gun and were able to frighten off an intruder.
      3. Many of the people who favor gun control are just frightened by guns.
      4. Many children are accidentally killed each year by guns in their homes.
      5. It’s a lot of fun to go out and try to shoot stop signs with a handgun.
    3. Give several premises that are relevant to the following conclusion. Then give several that are irrelevant:
      1. Abortion should be illegal.

    This page titled 10.2: Fallacy of Irrelevant Reasons is shared under a CC BY-NC 4.0 license and was authored, remixed, and/or curated by Jason Southworth & Chris Swoyer via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.