Logical Fallacies

Ad Hominem

To the Man. Argument by insult or mudslinging regarding appearance, ethnicity, character, or other non-relevant personal characteristic.

Strawman Argument

A scarecrow. An argument — often a more extreme version of the counterargument — attacked to make one's position look stronger.

Appeal to Ignorance

An argument must be true if there is no evidence against it.

False Dilemma

Polarizing, manipulative argument by false dichotomy between extreme positions.

Slippery Slope Fallacy

Argument without evidence that a ridiculous outcome will necessarily result from a given course of action.

Circular Argument

An argument that restates premise as conclusion and restates assumptions. "Begging the question" (petitio principii).

Hasty Generalization

Argument based on a few examples rather than substantial proof.

Red Herring Fallacy

Diversionary distraction using something unimportant to encourage a false conclusion. (Ignoratio elenchi)

Appeal to Hypocrisy

Tu Quoque (You Too). Attempt to divert blame by accusing opponent of similar misdeeds.

Causal Fallacy

Incorrect attribution of causation. E.g., came before, therefore caused by. (Post hoc ergo propter hoc)

Fallacy of Sunk Costs

Argument to keep doing something even if unlikely to produce a benefit because of time or money already spent.

Appeal to Authority

Argument by overstated, illegitimate, or irrelevant position or expertise.

Equivocation

Word, phrase, or sentence used deliberately to confuse, deceive, or mislead.

Appeal to Pity

Argument by provoking emotions to overcome logic.

Bandwagon Fallacy

Argument that something is true (or right or good) because others agree with it. (Argumentum ad populum)

Association Fallacy

Using an argument's connections to other concepts or people to support or refute it (guilt by association).

False Analogy

Making false or misleading comparisons (false equivalence).

Logic Leap

Making a jump in logic such that the conclusion does not follow from the premise (non sequitur).

Cherry Picking

Selectively using facts (card stacking).

Appeal to Probability

A statement that takes something for granted because it would probably be the case (or might be the case).

Argument from Fallacy

The assumption that, if a particular argument for a conclusion is fallacious, then the conclusion itself is false.

Base Rate Fallacy

Making a probability judgment based on conditional probabilities, without taking into account the effect of prior probabilities.

Conjunction Fallacy

The assumption that an outcome simultaneously satisfying multiple conditions is more probable than an outcome satisfying a single one of them.

Non-Sequitur Fallacy

Where the conclusion does not logically follow the premise.

Affirming a Disjunct

Concluding that one disjunct of a logical disjunction must be false because the other disjunct is true; A or B; A, therefore not B.

Affirming the Consequent

The antecedent in an indicative conditional is claimed to be true because the consequent is true; if A, then B; B, therefore A.

Denying the Antecedent

The consequent in an indicative conditional is claimed to be false because the antecedent is false; if A, then B; not A, therefore not B.

Existential Fallacy

An argument that has a universal premise and a particular conclusion.

Modal Fallacy

Confusing necessity with sufficiency. A condition X is necessary for Y if X is required for even the possibility of Y — but X alone does not bring about Y.

Argument to Moderation

Assuming that a compromise between two positions is always correct (false compromise, middle ground).

Continuum Fallacy

Improperly rejecting a claim for being imprecise (fallacy of the heap, sorites fallacy).

Definist Fallacy

Defining a term used in an argument in a biased manner using loaded terms.

Divine Fallacy

Arguing that, because something is incredible or amazing, it must be the result of superior, divine, or paranormal agency.

Motte-and-Bailey Fallacy

Conflating two positions — one modest and easy to defend (the motte) and one more controversial (the bailey). When challenged, retreating to the modest position.

Ecological Fallacy

Inferring about the nature of an entity based solely upon aggregate statistics collected for the group to which that entity belongs.

Etymological Fallacy

Assuming that the original or historical meaning of a word is necessarily similar to its actual present-day usage.

Fallacy of Composition

Assuming that something true of part of a whole must also be true of the whole.

Fallacy of Division

Assuming that something true of a composite thing must also be true of all or some of its parts.

False Dilemma / False Dichotomy

Two alternative statements are given as the only possible options when, in reality, there are more.

False Equivalence

Describing two or more statements as virtually equal when they are not.

Historian's Fallacy

Assuming that decision-makers of the past had identical information as those subsequently analyzing the decision.

Homunculus Fallacy

Explaining a concept in terms of the concept itself without explaining its real nature.

Inflation of Conflict

Arguing that, if experts in a field disagree on a point, no conclusion can be reached or the field's legitimacy is questionable.

Kettle Logic

Using multiple, jointly inconsistent arguments to defend a position.

McNamara Fallacy

Making an argument using only quantitative observations and discounting subjective information that focuses on quality.

Moving the Goalposts

Evidence presented in response to a specific claim is dismissed and some other (often greater) evidence is demanded.

Nirvana Fallacy

Solutions to problems are rejected because they are not perfect (perfect-solution fallacy).

Proof by Assertion

A proposition is repeatedly restated regardless of contradiction.

Special Pleading

The arguer attempts to cite something as an exemption to a generally accepted rule without justifying the exemption.

No True Scotsman

Makes a generalization true by changing the generalization to exclude a counterexample.

Cherry Picking

Using individual cases or data that confirm a particular position, while ignoring related cases or data that may contradict it.

Survivorship Bias

A small number of successes of a given process are actively promoted while completely ignoring a large number of failures.

Hasty Generalization

Basing a broad conclusion on a small or unrepresentative sample.

Misleading Vividness

Describing an occurrence in vivid detail, even if exceptional, to convince someone that it is more important than it is.

Thought-Terminating Cliché

A commonly used phrase used to quell cognitive dissonance or end debate with a cliché rather than a point.

Cum Hoc Ergo Propter Hoc

A faulty assumption that, because there is a correlation between two variables, one caused the other.

Post Hoc Ergo Propter Hoc

X happened, then Y happened; therefore X caused Y.

Wrong Direction

Cause and effect are reversed — the consequence of a phenomenon is claimed to be its root cause.

Fallacy of the Single Cause

It is assumed that there is one simple cause of an outcome when in reality it may have been caused by a number of jointly sufficient causes.

Gambler's Fallacy

The incorrect belief that separate, independent events can affect the likelihood of another random event.

Regression Fallacy

Ascribes cause where none exists by failing to account for natural fluctuations.

Appeal to the Stone

Dismissing a claim as absurd without demonstrating proof for its absurdity.

Argument from Ignorance

Assuming that a claim is true because it has not been or cannot be proven false, or vice versa.

Argument from Repetition

Repeating an argument until nobody cares to discuss it any more and referencing that lack of objection as evidence of support.

Appeal to Authority

An assertion is deemed true because of the position or authority of the person asserting it.

Courtier's Reply

A criticism is dismissed by claiming that the critic lacks sufficient knowledge or credentials to comment.

Appeal to Consequences

The conclusion is supported by a premise that asserts positive or negative consequences from some course of action.

Appeal to Nature

Judgment is based solely on whether the subject is natural or unnatural.

Appeal to Tradition

A conclusion supported solely because it has long been held to be true.

Argumentum ad Baculum

An argument made through coercion or threats of force to support a position.

Bulverism

Inferring why an argument is being used, associating it to some psychological reason, then assuming it is invalid as a result.

Fallacy of Relative Privation

Dismissing an argument or complaint due to what are perceived to be more important problems ("not as bad as").

Genetic Fallacy

A conclusion is suggested based solely on something or someone's origin rather than its current meaning or context.

Naturalistic Fallacy

Inferring evaluative conclusions from purely factual premises in violation of fact-value distinction.

Straw Man Fallacy

Misrepresenting an opponent's argument by broadening or narrowing the scope of a premise and refuting a weaker version of their argument.

Texas Sharpshooter Fallacy

Improperly asserting a cause to explain a cluster of data.

Tu Quoque

Stating that a position is false or should be disregarded because its proponent fails to act consistently in accordance with it (whataboutism).

Two Wrongs Make a Right

Assuming that, if one wrong is committed, another wrong will rectify it.