Logical Faults

hasty generalization

The writer bases the argument on insufficient or unrepresentative evidence. Suppose you owned a beagle, and the dog at some point attacked you. If you declare that beagles are vicious dogs, you are making a hasty generalization based on limited experience

non sequitur

It does not follow." The writer's conclusion is not necessarily a logical result of the facts. "Professor Smith is a famous historian, so he must be a fantastic history teacher." Well, just because a person knows a subject really well doesn't mean that h

begging the question

The writer presents as truth what is supposed to be proven by the argument. "That useless law, Reform Bill 17, needs to be repealed." The writer doesn't prove the law's uselessness but just assumes it-therefore, getting something for nothing like a beggar

red herring

An irrelevant point introduced to divert attention from the main issue. It is a common fault, especially for young people. "Maybe I did plagiarize part of my paper, but what about Jason? He cheats all the time and never gets in trouble!" The issue isn't a

ad hominem

The writer attacks the opponent's character rather than the opponent's argument. "Dr. Jones can't be a competent marriage counselor-she's divorced!" Despite her own marital status, Dr. Jones still might give excellent advice to her clients. Her personal l

ad populum

The writer evades the issue by appealing to readers' reactions to certain subjects. "True patriots will support the new educational spending proposal." Rather than discuss the proposal's merits, the writer appeals to emotions.

either/or

The writer tries to convince the reader that there are only two sides to an issue-one right, one wrong. "Are you going to college, or do you want to work at McDonald's aIl of your life?" The writer ignores the myriad other paths one's life might take rath

hypostatization

The writer uses an abstract concept as if it were a concrete reality. "History has taught us..." "They say that you should never..." "Science has proven..." However, "history" or "science" or "they" don't represent a single voice or opinion.

bandwagon appeal

The writer tries to validate a point by intimating that "everyone else believes in this." "Everyone who appreciates good food eats at this restaurant." "Truly sophisticated women wear that perfume." "Come on; everyone's doing it..." The writer never discu

straw man

The writer selects the opponent's weakest or most insignificant point to argue against in order to divert the readers' attention from the real issues. (It is similar to a red herring fault.) "Senator Jones says that we should not fund the nuclear submarin

faulty analogy

The writer uses an extended comparison as a substitute for proof. A compelling analogy might suggest similarities, but it doesn't prove anything. "If doctors can have x-rays to guide them during an operation, then students should be able to use their note

quick fix

The writer relies too heavily on a catchy slogan or phrase. The slogan might be clever and get people's attention, but it doesn't really prove anything. Slogans oversimplify the issue or make an empty claim. "When guns are outlawed, only outlaws will have

faulty use of authority

The writer relies on a person, organization, or other entity as an authority, but one with little bearing on the actual argument. It is misplaced ethos appeal. "My brother is in the army, and he says that terrorists would never strike here." "Abortion is

post hoc ergo propter hoc

The writer assumes that because one event follows another in time, the first event caused the second event. Usually, the relationship is merely coincidental. It's correlation, not causation. (Similar to non sequitur.) "They're going to lose tonight's game

circular thinking/logic

The second half of a writer's claim merely restates the first half in some way. The writer is "chasing his tail" so to speak because no specific, arguable assertion is made. "There aren't enough parking spaces in the school lot because there are too many