28 How Do I Avoid Logical Fallacies?

Insincere appeals to shared identity or values

Obviously, lying about who we are or what we believe in is not a valid way to build trust. An appeal to a shared identity that is not really shared or an appeal to a shared value that the writer does not really hold is certainly a breach of trust.

However, referring to an identity that the writer doesn’t share can be a legitimate gesture of goodwill, as long as the writer doesn’t misrepresent their own background. A white politician who interjects Spanish words into a speech to a largely Latinx audience is signaling that they want to appear friendly and empathetic to a Latinx identity. Of course, the politician’s accent may undermine this to some extent by reminding the audience of their different background. Will the audience be glad that the politician is trying? Will they be put off by a sense that the politician is presuming too much or encroaching on an identity that doesn’t belong to them? Writers will often try to signal respect and familiarity if they do refer to another group’s identity, as in “I know from talking to transgender friends that using a single-gender restroom can feel stressful and dangerous.”

Appeal to popularity (bandwagon)

An extremely common technique is to suggest that a claim is true because it is widely accepted. Of course, we do legitimately need to refer to other people’s opinions as guides to our own at times. An idea’s popularity may be a legitimate reason to investigate it further. It might be a reason to consider it influential and thus important to address in a discussion. But it’s popularity does not prove its validity. Popularity may be due to the correctness of the idea but it may be due to many other reasons as well.

Appeals to popularity encourage readers to base their decisions too much on their underlying desire to fit in, to be hip to what everybody else is doing, not to be considered crazy. Imagine that a talk show host introduces a guest as the author of a #1 New York Times bestseller about climate change and the coming apocalypse. But this is a fallacy. We’ve all known it’s a fallacy since we were little kids, the first time we did something wrong because all of our friends were doing it, too, and our mom or dad asked us, “If all of your friends jumped off a bridge, would you do that too?”

Personal attacks

We commit this fallacy when, instead of attacking an opponent’s views, we attack the opponent. What makes this a fallacy is the disconnect between the reason and the claim. Logicians call this an ad hominem fallacy, which means “to the person.” The opponent may have bad qualities, but these qualities do not make their argument incorrect. They may give legitimate reason to trust the argument less, but they do not invalidate it.

This fallacy comes in various forms; there are a lot of different ways to attack a person while ignoring (or downplaying) their actual arguments. Abusive attacks are the most straightforward. The simplest version is simply calling your opponent names instead of debating them. Donald Trump has mastered this technique. During the 2016 Republican presidential primary, he came up with catchy nicknames for his opponents, which he used just about every time he referred to them: “Lyin’ Ted” Cruz, “Little Marco” Rubio, “Low-Energy Jeb” Bush. If you pepper your descriptions of your opponent with tendentious, unflattering, politically charged language, you can get a rhetorical leg-up.

Another abusive attack is guilt by association. Here, you tarnish your opponent by associating them or his views with someone or something that your audience despises. Consider the following:

The argument just compared Dick Cheney to Hitler with only the tiniest shred of evidence. That evidence is not sufficient to make a legitimate comparison: if it were, then any person who favored giving most government power to one leader could be compared to Hitler. Clearly, consolidating power was not the most significant thing Hitler did, nor, in itself, is it the reason we have such negative associations with his name. Those powerful negative associations make comparisons to Hitler and the Nazis a powerful rhetorical strategy which is often used when it isn’t justified. There is even a fake-Latin term for the tactic: Argumentum ad Nazium (cf. the real Latin phrase, ad nauseum—to the point of nausea.

A circumstantial attack is not as blunt an instrument as its abusive counterpart. It also involves attacking one’s opponent, focusing on some aspect of their person—their circumstances—as the core of the criticism. This version of the fallacy comes in many different forms, and some of the circumstantial criticisms involved raise legitimate concerns about the relationship between the arguer and his argument. They only become fallacies when these criticisms are taken to be definitive refutations, which, on their own, they cannot be.

To see what we’re talking about, consider the circumstantial attack that points out one’s opponent’s self-interest in making the argument they do. Consider:

This argument is flawed. It doesn’t follow from the fact that the University received a grant from Monsanto that scientists working at that school faked the results of a study. But the fact of the grant does raise a red flag. There may be some conflict of interest at play. Such things have happened in the past (e.g., studies funded by Big Tobacco showing that smoking is harmless). But raising the possibility of a conflict is not enough, on its own, to show that the study in question can be dismissed out of hand. It may be appropriate to subject it to heightened scrutiny, but we cannot shirk our duty to assess its arguments on their merits.

A similar thing happens when we point to the hypocrisy of someone making a certain argument—when their actions are inconsistent with the conclusion they’re trying to convince us of. Consider the following:

This passage makes a strong point, but then commits a fallacy. It would appear that, indeed, the AFT leader is hypocritical; her choice to send her kids to private schools suggests (but doesn’t necessarily prove) that she doesn’t believe her own assertions about the quality of public schools. Again, this raises a red flag about her arguments; it’s a reason to subject them to heightened scrutiny. But it is not a sufficient reason to reject them out of hand, and to accept the opposite of her conclusions. That’s committing a fallacy. She may have perfectly good reasons, having nothing to do with the allegedly low quality of public schools, for sending her kids to the private school in the suburbs. Or she may not. She may secretly think, deep down, that her kids would be better off not going to public schools. But none of this means her arguments in the op-ed should be dismissed; it’s beside the point. Do her reasons back up her conclusion? Are her reasons true? Even if the person arguing is hypocritical, they may still be making a sound argument. We still need to decide whether their reasoning is valid before rejecting the argument.

A very specific version of the circumstantial attack, one that involves pointing out one’s opponent’s hypocrisy, is worth highlighting, since it happens so frequently. It has its own Latin name: tu quoque, which translates roughly as “you, too.” This is the “I know you are but what am I?” fallacy; the “pot calling the kettle black”; “look who’s talking”. It’s a technique used in very specific circumstances: your opponent accuses you of doing or advocating something that’s wrong, and, instead of making an argument to defend the rightness of your actions, you simply throw the accusation back in your opponent’s face—they did it too. But that doesn’t make it right.

The final variant of the circumstantial attack is perhaps the most egregious. It’s certainly the most ambitious: it’s a preemptive attack on one’s opponent to the effect that, because of the type of person they are, nothing they say on a particular topic can be taken seriously; they are excluded entirely from debate. It’s called poisoning the well. We poison the well when we exclude someone from a debate because of who they are. Imagine an English person saying, “It seems to me that you Americans should reform your healthcare system. Costs over here are much higher than they are in England. And you have millions of people who don’t even have access to healthcare. In the UK, medical care is a basic right of every citizen.” Suppose an American responded by saying, “What you know about it? Go back to England.” That would be poisoning the well. The English person is excluded from debating American healthcare just because of who they are.