Fallacies (Argument Unit) Definition/Example

Fallacy of Division

Brief Definition: What is true for the whole is true of the parts as well.

Example: The housing market in the United States has seen a major decline; therefore, there must be an economic downturn for housing in every city in America.

Circular Reasoning

Brief Definition: This error occurs when a person is arguing for something that is already assumed to be true in one of the argument's premises.

Example: I am an excellent parent because I think parenting is something I am good at.

Either/or Fallacy

Brief Definition: The portrayal of a complex situation in simplistic either/or terms, not acknowledging that (1) both alternatives could be true, (2) gray areas exist between the two alternatives, or (3) other possibilities exist.

Example: In the United States you are either a liberal or a conservative. (Your views could fall somewhere in the middle.)

Hasty Generalization

Brief Definition: Making an assumption about a group based on observing only a small portion of the group.

Example: "I just went in for minor repairs on my car and ended up having to pay a fortune for other repairs as well. I tell you all those car repairmen are crooks!" Assuming that all repairmen are crooks based on one bad experience is an example of hasty generalization.

The Fallacy of Composition

Brief Definition: Putting two or more good things together does not necessarily mean they will be good together.

Example: Just because you have several fantastic individual basketball stars does not necessarily mean that you are going to have a great team.

Post Hoc Ergo Propter Hoc

Brief Definition: Assuming that because B follows A, A must have caused B.

Example: A child has a big argument with her parents. About a month later they tell her that they are getting a divorce. The child thinks her parents' divorce is her fault because she argued so much.

Extravagant Hypothesis

Brief Definition: Formulating a complex or unlikely explanation for an event when a simpler explanation would do.

Example: Conspiracy theories often fall into this type of fallacy. For example, your favorite contestant on American Idol might have been voted off the show by the American public, but you feel the voting was rigged and/or the judges purposely said bad things to get this person eliminated.

False Analogy

Brief Definition: This is also called a weak analogy. This means that the similarities between the two things being compared are not substantial enough to assume that another characteristic of one of them probably applies to the other.

Example: The example in the textbook is a good one here: "Just as an apple tree under stress bears more fruit than another tree that lacks for nothing, so too a woman under stress will bear more children than one who suffers nothing at all."

Slippery Slope

Brief Definition: Once someone asks for one thing and receives it, they will not stop until they have taken it all.

Example: The textbook uses the example of gun control laws. Many people oppose a law that would eliminate hand guns or even semiautomatic weapons because they feel that if these laws are passed, gun control laws will continue until all guns, even hunting rifles, become illegal.

The Genetic Fallacy

Brief Definition: The mistaken belief that the origin of an idea has some bearing on the truth or falsity of the idea. Just because an idea comes from a famous person, an Ivy League scholar, or some other expert does not necessarily mean that the idea is a good one. The opposite is also true: Truth is truth no matter where the idea comes from.

Example: Unfortunately, this often can happen in the workplace: The boss listens to the ideas of only those in management positions, and assumes the ideas of the nonmanagerial workers are not worth listening to.

Appeal to Authority

Brief Definition: Justifying your ideas by appealing to an authoritative source. This is a good action if used correctly, but the belief that something is true just because an expert says so is not necessarily correct.

Example: Marketers, knowing that a certain percentage of the population desires to have similarities with famous people, often use those famous people to sell their products. For example, Michael Jordan promotes Hanes underwear. What does Michael Jordan have to do with underwear? He is an expert on basketball, but does that expertise extend to underwear? Probably not! Michael Jordan is not a known expert on underwear as the definition suggests he should be.

Appeal to Tradition

Brief Definition: Following traditions is good. However, you should not always just follow tradition for tradition's sake. Deciding something just because this is the way we have always done it is committing this fallacy. Note: This fallacy is a form of the Is/Ought fallacy seen below.

Example: A good example used in the textbook is the one about the builder. The builder is questioned on his building practices but he says, "That's the way I have been building these things for fifteen years." However, that does not mean he has been building them right for fifteen years!

The Is/Ought Fallacy

Brief Definition: Arguing that just because something is the case, it ought to be the case.

Example: Again, the textbook gives a great example here: "For example, it might seem reasonable enough to the casual thinker to say that people are sexual creatures (statement of fact) and therefore they ought to have sex (statement of obligation), but many would rightfully find no force behind this argument. They could argue that if we accept the premise that because people are sexual creatures they ought to be sexual, then we must also accept the argument that because people are aggressive creatures they ought to be aggressive."

Bandwagon Appeal

Brief Definition: This is an appeal to popularity. It is saying that something must be right because everybody is doing it.

Example: Teenagers use this argument with their parents often. They argue that having sexual intercourse, drinking alcohol while underage, smoking cigarettes, etc... are okay because their friends are all doing it. If everyone is doing it then how can it be wrong?

Appeal to Ignorance

Brief Definition: Saying something must be true (or false) because there is little-to-no evidence to prove that it is not true (or not false).

Example: You have a family member who has a terminal disease. You hear of a possible new cure being offered in another country. You contact the group promoting this cure and ask if it works. They say, "No one has ever shown that it doesn't work, so of course it works!"