Logical Fallacies

Equivocation

A fallacy by which a key word or phrase in an argument is used with more than one meaning. "I trust you so I trust that you'll be home by 9." The word "trust" is used in two different ways.

Faulty Appeal to Authority

A fallacy in which a speaker or writer seeks to persuade not by giving evidence but by appealing to the respect people have for a famous person or institution.

Special Pleading

A fallacy of logical argument in which the writer suppresses evidence that contradicts the conclusion in an inductive argument.

Slippery Slope

A fallacy that assumes that taking a first step will lead to subsequent steps that cannot be prevented.

False Cause

A fallacy that occurs when the alleged cause fails to be related to, or to produce the effect: "the black cat crossing the street brought me bad luck, so I had an accident."

Bandwagon

A fallacy which assumes that because something is popular, it is therefore good, correct, or desirable.

Circular Reasoning

A logical fallacy in which the conclusion is hidden within the premises. Typically called "circular reasoning." From Plato's Euthyphro - something is pious because it is loved by the gods. That which is loved by the gods is pious.

Red Herring

A red herring is the introduction of an irrelevant or random point into an argument mean to change the subject.

Weak Analogy

An analogy is a comparison. They can be weak because no two things are alike.

Burden of Proof Reversal

An argument in which one who asserts a position fails to prove it, but rather tries to get the interlocutor to disprove it. A good argument is proven by the one who asserts it and it doesn't fall upon one who is skeptical of the claim to disprove it, but rather the asserter of the position to prove it.

Argument from Ignorance

An argument stating that something is true because it has never been proven false.

Ambiguity

An event or situation that may be interpreted in more than one way. Also, the manner of expression of such an event or situation may be ambiguous. Artful language may be ambiguous. Unintentional ambiguity is usually vagueness.

Propaganda

Appeal to Fear Appeal to Pity Bandwagon Appeal to Tradition Appeal to Flattery

Personal Incredulity

Arguing that because something is difficult to understand it must necessarily be untrue.

Argument for Ignorance

Arguing that it is better to be ignorant than to know the truth.

Loaded Question

Asking a question that has an assumption built into it so that it cannot be answered without making one appear guilty. "Do you still beat your girlfriend?"

The Presentist Fallacy

Assuming that because something is currently a particular way that it is the way that it ought to be.

Nostalgic Fallacy

Assuming that because something was a certain way that is the way that it ought to be.

Middle-Ground Fallacy

Assuming that the middle position between two others is always the right one.

Whole to Part or Part to Whole

Assuming that what is true about one part of something is also true about the whole.

Future Fallacy

Assuming the future will be like the present.

Making Assumptions

Circular Reasoning Loaded Question Whole to Part Either-Or (Black or White) Slippery Slope

Genetic Fallacy

Condemning an argument because of where it began, how it began, or who began it. Similar in form to ad-hominem.

Arguing From a False Premise

Deriving a conclusion from at least one false premise.

Tu quoque

Dismissing someone's argument because he or she is being hypocritical.

Hasty Generalizations

Generalizing based on a small or poor sample population.

Statistical Fallacies

Hasty Generalizations Weak Analogies

Ad-hominem

In an argument, this is an attack on the person rather than on the opponent's ideas. It comes from the Latin meaning "turn to the man."

Texas Sharpshooter

Jumping to the conclusion that a cluster in some data must be the result of a cause.

Post Hoc Ergo Propter Hoc

Latin for "after this therefore because of this." Arguing that because something follows something else it necessarily is the cause.

Non-Sequitur

Latin for "does not follow." An argument in which the conclusion does not follow from the premises.

No True Scotsman

Making what could be called an appeal to purity as a way to dismiss relevant criticisms or flaws of an argument. John: "No Scotsman would ever drink wine." Jim: "But McDougal is a Scotsman and he drinks wine." John: "Well, no true Scotsman would ever drink wine."

Strawman

Misrepresenting or exaggerating someone else's argument to make it easier to attack.

Appeal to Emotion

Occurs when emotions or emotionally-charged language is used in an attempt to persuade the reader. Using manipulative emotion instead of valid argument to convince.

The Fallacy Fallacy

Presuming that because a claim has been poorly argued, or a fallacy has been made, that the conclusion is necessarily wrong.

Avoiding the Question

Red Herring Fallacy Ad Hominem Tu Quoque Faulty Appeal to Authority Appeal to the People Straw Man

Appeal to Nature

This argument goes that because something is natural, it must be better.

Anecdotal

Using personal experience or an isolated example instead of a valid argument especially to dismiss statistics.

Black or White

When two alternative states are presented as the only possibilities, when in fact more possibilities exist.

Appeal to People

When we assume a viewpoint is correct because many people agree with it.