Logical Fallacies -- Definitions

What is an Appeal to Novelty?

Focuses on the assumption that the newness of an idea is evidence of its truth.

What are Fallacies of Presumption?

These contain false premises, and so fail to establish their conclusion.

What is a Logical Fallacy?

A standard form of flawed reasoning that seduces and persuades the unaware with claims that attempt to support an argument, but are not logically sound, which leads to faulty conclusions.

What are Fallacies of Relevance?

Fallacies that rely on premises irrelevant to the truth of the conclusion.

What is Complex Question Fallacy?

Focuses on a question with a false, disputed, or question-begging presupposition that is "loaded" with that presumption all answers appear to endorse that assumption.

What is a Hasty Generalization Fallacy?

Focuses on a sample that is either too small or too special to be representative of a population.

What is a Weak Analogy?

Focuses on a weak comparison.

What is an Appeal to Force?

Focuses on an attempt to persuade using threats; disbelief will be met with sanctions.

What is an Appeal to Irrelevant Authority?

Focuses on an authority who is not an expert on the issue at hand, an idea is attributed to a vague collective, or it appeals to ancient wisdom because it was believed to be true long ago.

What is Guilt by Association?

Focuses on arguing that some group of people is absolutely and categorically bad and sharing even a single attribute with said group would make one a member of it, which then bestows all the associated evils.

What is a Red Herring?

Focuses on distraction, and is committed with a diversion created by introducing another topic.

What is an Appeal to Consequences?

Focuses on speaking for or against the validity of a proposition by appealing to the consequences of accepting or rejecting it; appeals to emotions of hope or fear.

What is a Cum Hoc Ergo Propter Hoc Fallacy?

Focuses on the assumption that because two things occur together, they must be causally related; "With this, therefore because of this."

What are Fallacies of Ambiguity?

These manipulate language in misleading ways.

What is an Ad Populum?

Uses the fact that a sizable number of people, perhaps even a majority, believe in something as evidence that it must therefore be true; relies on bandwagon [Everyone is doing it.], patriotic [It is the American way.], and snob [Only the best are doing it.] approaches.

What is Circular Reasoning?

Focuses its conclusion among its premises; assumes (either explicitly or not) what it is trying to prove; begging the question.

What is an Ad Hominem?

Focuses not on the evidence for a view, but on a negative character trait of person advancing it; seeks to discredit positions by discrediting those who hold them.

What is a Non-Sequiter?

Focuses on a conclusion does not follow from the premises; the conclusion could be either true or false, but the argument is fallacious because there is a disconnection between the premise and the conclusion; all invalid arguments are special cases of non sequitur.

What is a Sweeping Generalization Fallacy?

Focuses on a general rule, and applies it to an obviously abnormal instance, or focuses on countering abnormalities by arbitrarily redefining the criteria for membership into that category.

What is an Appeal to Antiquity?

Focuses on a premise that must be true because people have always believed it or done it; may also conclude that the premise has always worked in the past and will thus always work in the future.

What is an Appeal to Pity?

Focuses on arousing the emotions of an audience in order to gain acceptance of an argument's conclusion.

What is a Moralistic Fallacy?

Focuses on assuming that aspects of nature which have morally, socially, or politically unpleasant consequences cannot exist.

What is a Gambler's Fallacy?

Focuses on assuming that short-term deviations from probability will be corrected in the short-term; however, past results don't bear on what will happen next.

What is an Appeal to Poverty?

Focuses on assumption that a position is correct because it is held by the poor; stems from temptation to contrast excesses, greed, and immorality of the rich with the simplicity, virtue, and humility of the poor.

What is an Appeal to Wealth?

Focuses on assumption that someone is better because they are wealthier or something is better because it is more expensive; stems from a society where wealth is held up as that to which we all aspire, and the rich can be thought to deserve more respect than the poor, just as more expensive goods are thought to be better than less expensive goods solely because of their price.

What is a Genetic Fallacy?

Focuses on either devaluing or defending an argument because of its source, rather than its merit; emotional attachment to an idea's origins creates difficulty in disregarding it due to evaluating the origin.

What is an Equivocation Fallacy?

Focuses on exploiting the ambiguity of language by changing the meaning of a word during the course of an argument and using the different meanings to support some conclusion.

What is a Fallacy of Division?

Focuses on inferences derived from fact that a whole has a property, to reach the conclusion that a part of the whole also has that property.

What is a Straw Man Fallacy?

Focuses on misrepresenting, misquoting, misconstruing, and oversimplifying.

What is a Naturalistic Fallacy?

Focuses on premises that because something is "natural" it is therefore valid, justified, inevitable, good or ideal.

What is a Fallacist's Fallacy?

Focuses on rejecting an idea as false simply because the argument offered to provide justification for an accurate conclusion is faulty.

What is a Post Hoc Ergo Propter Hoc Fallacy?

Focuses on the assumption that because one thing occurred after another, it must have occurred as a result of it; "After this, therefore because of this."

What is a False Dilemma?

Focuses on the assumption that there are only two options and one is unacceptable so the other must be accepted.

What is a Fallacy of Composition?

Focuses on the fact that every part of a whole has a given property, and then inferring that the whole composition also has that property.

What is a Slippery Slope Fallacy?

Focuses on the false assumption that one thing must lead to another; suggests that one thing will lead to another, which leads to another until doing something unintended.

What is a Tu Quogue Fallacy?

Focuses on the hypocrisy of assuming that because someone else has done a thing there is nothing wrong with also doing it; Counters a charge with a charge; "You too!"

What is Arguing from Ignorance?

Focuses on the inference that a proposition is true from the fact that it is not known to be false.

What is Affirming the Consequent?

Stated: (1) If A then B. (2) B. (3) Therefore, A. (1) notes that what A obtains, by consequence B also obtains. (2) asserts that this consequence B does obtain. The faulty step then follows: (3) the inference that A also obtains the same consequence.