Logical Fallacies These are bad.

What is a logical fallacy? That term refers to “faulty logic.” Generally speaking, logical fallacies are errors in reasoning. These errors undermine the strength of the argument and hurt the credibility of the author/speaker.

Why are we concerned about logical fallacies? The ability to identify logical fallacies in the arguments of others, and to avoid them in one’s own arguments, is a valuable skill. Fallacious reasoning hides the truth. When we can’t identify fallacies, we’re vulnerable to manipulation by those skilled in the art of persuasion.

Ad hominem In this fallacy, a personal attack is made against an opponent’s character instead of against an argument (sometimes called “name-calling”). Examples: Greenpeace doesn’t do any good because its members are a bunch of hippies. People who disagree with affirmative action are racists. You’re so stupid that your point couldn’t possibly be valid.

Ad ignorantium This argument assumes that if something can’t be proven true, it must be false—and vice versa. Examples: God doesn’t exist; you can’t prove he does. God does exist; you can’t prove he doesn’t. I don’t think this argument is going anywhere, do you?

Ad populum This emotional appeal speaks to positive (such as patriotism, religion, democracy) or negative (such as terrorism or socialism) concepts rather than the real issue at hand. Example: If you were a true American, you’d support the 2nd Amendment. Nobody wants to be called unpatriotic!

Appeal to force This argument says that something bad will happen if the audience doesn’t agree. Example: If you don’t believe in God, you’re going to hell. Appeal to force includes threats and is designed to scare the audience.

Argument from personal incredulity This argument goes like this: “I cannot explain or understand this; therefore, it cannot be true.” Example: I cannot imagine how natural forces could create the complexity of nature; evolution just can’t be possible! Pointing out your own ignorance is not a good persuasive technique.

Bandwagon fallacy Something is assumed to be valid because of popular support. Examples: Does God exist? Billions of people can’t be wrong! But Mom! Everybody has that kind of phone! Nobody wants to be left out!

Circular reasoning This claim uses its own conclusion as evidence; it says the same thing twice, ending up where it started. Examples: God exists. I know that because the Bible says so, and the Bible is the inspired word of God. Martin Luther King Jr. was a great speaker because he was so eloquent. We’re going in circles!

Complex cause A complex event is shown as having only one cause. Example: We lost the game because Gertrude missed the last shot. This argument is as logical as putting the blame on the first missed shot of the game.

Either/or fallacy (false dilemma) Only two options are given when many choices exist. Examples: Either you’re for the Republican plan or you’re a socialist. We can stop using fossil fuels, or we can destroy the earth. Few issues are this black and white.

Equivocation This fallacy uses a word with two different meanings. Examples: The sign said, “Fine for Parking Here,” so since it was fine, I parked here. God helps those who help themselves, so I’m going to help myself to more tater tot hot dish. People who equivocate often think they’re very clever. They’re not.

False analogy This fallacy compares two things that are not similar enough to compare. Example: That political candidate is the Jesus Christ of the 21st century. Really?

Faulty cause and effect This argument attempts to make a connection between two consecutive events. Example: Shortly after that phone call, I saw Gertrude crying. She must have gotten some bad news. We can’t make that claim without more information.

Genetic fallacy This argument brings up irrelevant history or origin. Example: Hitler’s regime developed the Volkswagen Beetle, so you shouldn’t buy one. Hitler isn’t making any money on VW sales, is he? What is the philosophy of that company now?

Hasty generalization This claim draws a conclusion based on insufficient evidence. Examples: Women are bad drivers. All frat boys love to party. Even though this is only the first day, I can tell this class is going to be boring. Many hasty generalizations are based on stereotypes.

Moral equivalence Something minor is compared to something serious, as if they are equal. Example: The police officer who gave me a ticket is a Nazi. While you might be trying to use hyperbole for effect, be careful about doing so using terms like “Nazi.”

Prejudicial language Loaded words and terms are used. Examples: Right-wing fanatics and NRA stormtroopers will fight to keep their guns. Bleeding-heart liberals are going to drive this country into bankruptcy. Do you think the “right-wing fanatics” and “bleeding-heart liberals” are willing to continue this discussion?

Red herring This diversionary tactic detracts from or avoids the issue at hand. Examples: The levels of mercury in seafood might be unsafe, but what else are fishers supposed to do for a living? Question: Did the president have an affair? Answer: The president is busy with Middle East peace talks and has no time for silly accusations. Do you know what a herring is?

Slippery slope This argument follows a claim to an unsupported conclusion. Example: If you skip class once, you’ll do it again…and again…and again—and before you know it, you’ll have dropped out of school and be living in a van down by the river.

Straw man This move misrepresents or oversimplifies an opponent’s viewpoint and then attacks it. Example: Proponents of sex education want to give kids license to have sex with no consequences. Do you really think that’s what they want?

Two wrongs This argument attempts to use one wrong to justify another. Examples: So what if I cheated on my taxes? Lots of people do. You say I shouldn’t speed, but you do. Two wrongs don’t make a right!