How's That Again? Logical Fallacies
- While driving to his next performance, a juggler was stopped by the police. “What are those knives doing in your car?” asked the officer.
- “I juggle them in my act.”
- “Oh yeah?” says the cop. “Let's see you do it.”
- So the juggler starts tossing and juggling the knives.
- A guy driving by sees this and says, “Wow, am I glad I quit drinking. Look at the test they're making you do now!”
Faulty logic—like the example here—can demolish the most carefully constructed persuasive essay. It's one of the surest ways to lose your readers. Following are the most common logical fallacies, errors in reasoning. They are arranged in alphabetical order.
“Well-known” information is another form a bogus claim can take. Be wary of sources that tell you that “Everybody knows that …” or “It is a well-known fact that …”
Loaded terms are sometimes used in inflammatory essays that deal with politics.
- Ambiguity. Deliberately using expressions that are confusing because they have more than one meaning.
- Argument to the person. Attacking the person rather than the topic.
- Begging the question. Circular reasoning that offers the argument itself as proof.
- Bogus claims. The writer promises more than he or she can deliver.
- Card stacking. Ignoring evidence on the other side of the issue.
- Either-or fallacy. Offering only two choices when other valid ones exist.
- False analogies. Misleading comparisons.
- Guilt by association. Attacking a person's beliefs because of the person's associations.
- Jumping on the bandwagon. Suggesting that something is right because everyone else does it.
- Hasty generalization. Generalizing from inadequate evidence, such as stereotyping.
- Irrelevant argument. A conclusion that does not relate to the premise.
- Loaded terms. Slanted or biased terms, especially those with strong connotations.
- Misrepresentation. Outright lies or other deliberate misrepresentation.
- Oversimplifying the issue. Twisting the truth by presenting too narrow a range of possibilities.
- Post hoc ergo propter hoc. Latin for “after this, therefore because of this,” it is the mistake of confusing after with because.
- Red herring. Diverting the issue with an unrelated topic.
- Self-contradiction. Arguing two premises that cannot both be true.
- Taking the issue out of context. Distorting the issue by taking it out of context.
These are sneaky little critters, so be especially vigilant. Reread your papers to make sure that every point you make is valid and logical. And while you're at it, check that you haven't built your entire argument on a fallacy. If that happens, even the best prose won't save the day.
Excerpted from The Complete Idiot's Guide to Writing Well © 2000 by Laurie Rozakis, Ph.D.. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.