Logical Fallacies

Begging the Question

A complicated fallacy; an argument that begs the question asks the reader to simply accept the conclusion without providing real evidence by saying the same point in different words. the argument either relies on a premise that says the same thing as the conclusion (which you might hear referred to as "being circular" or "circular reasoning"), or simply ignores an important (but questionable) assumption that the argument rests on. Sometimes people use the phrase "beg the question" as a sort of general criticism of arguments, to mean that an arguer hasn't given very good reasons for a conclusion, but that's not the meaning we're going to discuss here.

Post Hoc, Ergo Propter Hoc

A faulty assumption that the cause of a relationship is the result of what preceded it. Also known as Faulty Causality.

Non Sequitur

A gap in the sequence of your logic. Usually what happened is that the writer leaped from A to B and then jumped to D, leaving out step C of an argument he/ she thought through in her head, but did not put down on paper.

Ad Misericordiam

An emotional appeal in which the goal is to create outrage based on something hyperbolic or irrelevant.

Stacking the Deck

Any evidence that supports an opposing argument is rejected, omitted, or ignored.

Poisoning the Well

Attacking an argument by attacking the opponent (discrediting them) before they can present their argument.

Appeal to Tradition

Because something has always been done a particular way, it should continue to be done that way.

Moving the Goalposts

Changing the criteria to win an argument after the original one has been met, to avoid being proven wrong. This means rejecting an already valid counterargument and demanding another one based on new criteria.

Appeal to Ignorance

Lacks conclusive evidence (data, facts, statistics) about the issue being discussed. Therefore, the arguer states that one should accept his or her conclusion on the presented issue.

Hasty Generalization

Making assumptions about a whole group or range of cases based on a sample that is inadequate (usually because it is atypical or just too small).

Weak Analogy

Many arguments rely on an analogy between two or more objects, ideas, or situations. If the two things that are being compared aren't really alike in the relevant respects, the analogy is a weak one, and the argument that relies on it commits the fallacy of weak analogy.

Hypothesis Contrary to the Fact

Offering poorly supported claims about what might have happened in the past or future if (the hypothetical part) circumstances or conditions were different. The fallacy also entails treating future hypothetical situations as if they are fact.

Appeal to Authority

Often we add strength to our arguments by referring to respected sources or authorities and explaining their positions on the issues we're discussing.

Circular Reasoning

One statement is true because of the other statement, and the other statement is true because of the previous statement. A claim is supported by its reasoning; the argument begins where it ends. Often depicted as: X is true because of Y and Y is true because of X.

Straw Man

One way of making our own arguments stronger is to anticipate and respond in advance to the arguments that an opponent might make. The arguer sets up a wimpy, distorted, or misrepresented version of the opponent's position (counterargument) and tries to score points by knocking it down.

Red Herring

Partway through an argument, the arguer goes off on a tangent, raising a side issue that distracts the audience from what's really being discussed. Often, the arguer never returns to the original issue.

Appeal to Pity

Takes place when an arguer tries to get people to accept a conclusion by making them feel sorry for someone - it includes the technique of pathos.

Slippery Slope

The arguer claims that some form of chain reaction, usually ending in some dire consequence, will take place, but there's really not enough evidence for that assumption.

Missing the Point

The premises of an argument support a particular conclusion--but not the conclusion that the arguer actually draws

Equivocation

sliding between two or more different meanings of a single word or phrase that is important to the argument.

False Dichotomy

the arguer sets up the situation so it looks like there are only two choices. The arguer then eliminates one of the choices, so it seems that we are left with only one option: the one the arguer wanted us to pick in the first place.