If you’re in the policy comms world, you come face to face with logical fallacies every day — maybe every hour. You’re up against misinformation, disinformation and sometimes sheer nonsense. You have to deal with arguments that might sound convincing but really aren’t. And you don’t know how to respond because, all too often, you’re not sure yourself that an argument used against you doesn’t actually make sense.

Well, relax. Amanda Ruggeri on the BBC website offers seven helpful “ways to spot a bad argument,” or “logical fallacies,” as the great philosophers (thinking of you, Bertrand Russell) call them. Here they are.

1. The Ad Hominem This is used in an attempt to discredit a claim by attacking the person (or organization) that made it — and thereby avoiding addressing the merits of the claim itself. “Think of the health professional who is told that they are only recommending vaccines because they must be a shill for Big Pharma,” Ruggeri writes. Often, the ad hominem attack dredges up some claim that, even if true, is irrelevant: The person who made the claim, for example, was once stopped for speeding.
2. The Slippery Slope. This one “distracts attention using a hypothetical future possibility.” The argument avoids addressing the merits of a proposal by imagining what will happen somewhere down the line. Policy A will lead to outcome B which will lead, eventually, to outcome Z, which none of us want. When proponents of the Vietnam War used it, it was called the “domino theory.”
3. The Strawman. Closely related to the Slippery Slope, the Strawman approach intentionally distorts the argument and then extrapolates from that mischaracterization to reach a preposterous conclusion. To the reasonable observation that excessive sugar intake may increase the risk of heart disease, the Strawman argument would say, “So sugar is killing everyone and should be outlawed? That’s ridiculous.”
4. The False Dichotomy. This one presents only two either/or options, grossly limiting the actual range of possibilities. David Hackett Fischer in his excellent book Historians’ Fallacies offers a list of them, drawn from the titles of real books from reputable publishers. “Industry-Wide Collective Bargaining — Promise or Menace?” is one. “The Robber Barons — Pirates or Pioneers?” is another.
5. Whataboutism. This one is inescapable, especially when discussing politics. The point is to change the subject. To the statement, “Hunter Biden is a crook,” for example, the predictable response might be, “Well, what about Jared Kushner’s father? Hmmm?” (Both can be true, or both false. Or some other possibility.)
6. The Appeal to Authority. We should vote for Kamala Harris because Sally Field plans to? Or vote for Donald Trump because Hulk Hogan will? Usually, the Appeal to Authority takes a more subtle form. Neil deGrasse Tyson — who is an astrophysicist — often makes broad statements about subjects well beyond his area of expertise. Noam Chomsky, a linguist, does the same, making a name for himself on questions of American foreign policy. Should these people be cited as authorities on such subjects? Maybe, but the appeal to authority is still a logical trap. Even so, most of us were dying to know who Taylor Swift would endorse.
7. The Appeal to Ignorance. This one is used when a lack of evidence is used as a form of evidence. Ruggeri offers this example: Do lizards rule the world? People who believe that lizards do in fact rule the world might explain the lack of evidence this way: “Well, these lizards are too clever to leave any evidence — that’s what makes this situation so dangerous! How can you be sure it’s not true?” Conspiracy theorists routinely use this argument, shifting the burden of proof — or disproof — to the other lizard. I mean, the other person.

Familiarizing ourselves with logical fallacies is helpful. It can make it easier to recognize them when used against us — and when we are tempted to employ them ourselves. And you don’t need to be Aristotle or Sherlock Holmes to spot them. Even Davy Crockett could do it. Once, responding to some utterance by Andrew Jackson, Crockett said, “That doesn’t even make good nonsense.”