In her book, Critical Thinking: An Appeal To Reason, Peg Tittle has an interesting and useful way of organizing 15 logical fallacies. Simply put, they’re all irrelevant to the assessment of whether an argument is true or not. Using Tittle’s guidelines, we can quickly sort out what we need to pay attention to and what we can safely ignore.
Though these fallacies are irrelevant to truth, they are very relevant to persuasion. Critical thinking is about discovering the truth; it’s about the present and the past. Persuasion is about the future, where truth has yet to be established. Critical thinking helps us decide what we can be certain of. Persuasion helps us make good choices when we’re uncertain. Critical thinking is about truth; persuasion is about choice. What’s poison to one is often catnip to the other.
With that thought in mind, let’s take a look at Tittle’s 15 irrelevant fallacies. If someone tosses one of these at you in a debate, your response is simple: “That’s irrelevant.”
- Ad hominem: character– the person who created the argument is evil; therefore the argument is unacceptable. (Or the reverse).
- Ad hominem: tu quoque– the person making the argument doesn’t practice what she preaches. You say, it’s wrong to hunt but you eat meat.
- Ad hominem: poisoning the well— the person making the argument has something to gain. He’s not disinterested. Before you listen to my opponent, I would like to remind you that he stands to profit handsomely if you approve this proposal.
- Genetic fallacy– considering the origin, not the argument. The idea came to you in a dream. That’s not acceptable.
- Inappropriate standard: authority– An authority may claim to be an expert but experts are biased in predictable ways.
- Inappropriate standard: tradition – we accept something because we have traditionally accepted it. But traditions are often fabricated.
- Inappropriate standard: common practice – just because everybody’s doing it doesn’t make it true. Appeals to inertia and status quo.Example: most people peel bananas from the “wrong” end.
- Inappropriate standard: moderation/extreme – claims that an argument is true (or false) because it is too extreme (or too moderate). AKA the Fallacy of the Golden Mean.
- Appeal to popularity: bandwagon effect– just because an idea is popular doesn’t make it true. Often found in ads.
- Appeal to popularity: elites – only a few can make the grade or be admitted. Many are called; few are chosen.
- Two wrongs –our competitors have cheated, therefore, it’s acceptable for us to cheat.
- Going off topic: straw man or paper tiger– misrepresenting the other side. Responding to an argument that is not the argument presented.
- Going off topic: red herring – a false scent that leads the argument astray. Person 1: We shouldn’t do that. Person 2: If we don’t do it, someone else will.
- Going off topic: non sequitir – making a statement that doesn’t follow logically from its antecedents. Person 1: We should feed the poor. Person 2: You’re a communist.
- Appeals to emotion– incorporating emotions to assess truth rather than using logic. You say we should kill millions of chickens to stop the avian flu. That’s disgusting.
Chances are that you’ve used some of these fallacies in a debate or argument. Indeed, you may have convinced someone to choose X rather than Y using them. Though these fallacies may be persuasive, it’s useful to remember that they have nothing to do with truth.