Logical Fallacies

Abusive Ad Hominem

Attacking a person’s character, traits, or behavior instead of addressing the person’s argument.

Accent

Using ambiguity created by emphasis, stress, or pronunciation to give a statement a misleading meaning.

Accident

Applying a general rule to a particular case where an important exception makes the rule inappropriate.

Ad Baculum

Using threats, force, or fear as the primary support for accepting a conclusion.

Ad Consequentiam

Arguing that a claim is true or false because its consequences would be desirable or undesirable.

Ad Crumenam

Arguing that a wealthy or financially successful person’s position must be correct because of their wealth.

Ad Hoc Rescue

Adding an unsupported explanation solely to protect a claim from a counterexample or criticism.

Ad Hominem

Rejecting an argument by attacking the person presenting it rather than addressing the argument.

Circumstantial Ad Hominem

Rejecting someone’s argument because of their circumstances, interests, relationships, or situation.

Ad Misericordiam

Appealing to pity or sympathy instead of providing relevant evidence.

Ad Novitatem

Claiming that something is better or more correct simply because it is new.

Ad Numerum

Claiming that a belief is true because many people believe it.

Ad Populum

Appealing to popular opinion, common belief, or the desires of a group instead of relevant evidence.

Ad Verecundiam

Appealing improperly to an authority or expert instead of providing adequate evidence.

Affirming the Consequent

Reasoning that because If A then B, and B is true, A must therefore be true.

All-or-Nothing

Treating a situation as having only complete success or complete failure, with no middle possibilities.

Ambiguity

Using a statement or term whose meaning is unclear or capable of multiple interpretations.

Amphiboly

Using a grammatically ambiguous statement in a way that permits a misleading interpretation.

Anecdotal Evidence

Using an individual story or personal experience as inadequate evidence for a broader conclusion.

Anthropomorphism

Attributing human qualities, intentions, thoughts, or emotions to nonhuman things.

Appeal to Authority

Claiming something is true because an authority or expert says it is, without adequately establishing the authority’s relevance or reliability.

Appeal to Consequence

Arguing that a proposition must be true or false because its consequences would be desirable or undesirable.

Appeal to Emotion

Using emotions rather than relevant evidence as the primary support for a conclusion.

Appeal to Force

Attempting to establish a conclusion through threats or the possibility of punishment.

Appeal to Ignorance

Claiming that something is true because it has not been proven false, or false because it has not been proven true.

Appeal to Money

Assuming that wealth or financial success makes someone’s opinion more credible.

Appeal to Past Practice

Arguing that something should be done because it has been done in the past.

Appeal to Pity

Using sympathy for someone as evidence that their conclusion should be accepted.

Appeal to Snobbery

Claiming something is better or correct because it is associated with a prestigious or elite group.

Appeal to the Gallery

Appealing to the attitudes or opinions of an audience rather than providing relevant evidence.

Appeal to the Masses

Arguing that a claim is true because large numbers of people believe it.

Appeal to the Mob

Using the emotional reaction of a crowd or group as support for a conclusion.

Appeal to the People

Claiming that a proposition is true because it is popular or widely accepted.

Appeal to Traditional Wisdom

Claiming that a belief or practice is correct because it has traditionally been accepted.

Appeal to Vanity

Using someone’s desire for praise, admiration, or status to persuade them.

Appeal to Unqualified Authority

Using the opinion of someone without appropriate expertise as evidence for a conclusion.

Argument from Outrage

Using anger or moral outrage as if the emotional reaction itself proves a conclusion.

Argumentum Consensus Gentium

Claiming that a belief is true because it is universally or widely accepted.

Availability Heuristic

Overestimating the importance or likelihood of something because a vivid or memorable example is easily recalled.

Avoiding the Issue

Changing the subject or discussing irrelevant matters instead of addressing the actual issue.

Bad Seed

Rejecting an argument or group because one member is considered bad or defective.

Bald Man

Assuming that because individual additions or changes seem insignificant, a cumulative change must also be insignificant.

Bandwagon

Claiming that someone should accept a belief because many other people accept it.

Begging the Question

Assuming the conclusion within the premises instead of independently establishing it.

Beside the Point

Providing information that may be relevant to something but does not address the actual issue being argued.

Biased Generalizing

Drawing a general conclusion from evidence selected or interpreted in a biased way.

Biased Sample

Using a sample that does not adequately represent the population from which a conclusion is drawn.

Biased Statistics

Presenting or selecting statistics in a misleading way to support a predetermined conclusion.

Bifurcation

Dividing a situation into two alternatives while ignoring other possibilities.

Black-or-White

Treating only two extreme alternatives as possible when additional options exist.

Caricaturization

Attacking an exaggerated or distorted version of an argument instead of the actual argument.

Changing the Question

Replacing the original question with a different question that is easier to answer.

Cherry-Picking

Selecting only evidence supporting a conclusion while ignoring relevant contradictory evidence.

Circular Reasoning

Using a conclusion, directly or indirectly, as its own support.

Clouding the Issue

Obscuring the main issue with irrelevant, confusing, or distracting information.

Common Belief

Assuming that a belief is true because it is commonly accepted.

Common Cause

Incorrectly treating two correlated events as causally connected when both are actually caused by a third factor.

Common Practice

Claiming that an action is justified merely because many people commonly do it.

Complex Question

Asking a question that contains an unsupported assumption within it.

Composition

Assuming that what is true of individual parts must also be true of the whole.

Confirmation Bias

Seeking, noticing, or interpreting evidence in ways that favor an existing belief while overlooking contrary evidence.

Confusing an Explanation with an Excuse

Treating an explanation of why something happened as if it were a justification for the action.

Conjunction

Incorrectly judging a combination of events as more probable than one of its individual components.

Consequence

Using the consequences of believing a proposition as evidence that the proposition itself is true or false.

Contextomy

Removing a statement from its surrounding context in a way that changes or distorts its meaning.

Converse Accident

Assuming that what is true in a particular case must therefore be true generally.

Cover-up

Deliberately hiding relevant evidence or information that would undermine a conclusion.

Cum Hoc, Ergo Propter Hoc

Assuming that because two things occur together, one causes the other.

Curve Fitting

Creating a model that fits existing data excessively closely and therefore performs poorly on new data.

Definist

Defining a disputed term unfairly so that a controversial conclusion becomes easier to defend.

Denying the Antecedent

Reasoning that if A implies B, and A is false, then B must also be false.

Disregarding Known Science

Ignoring established scientific evidence that contradicts a claim.

Distraction

Introducing irrelevant information to divert attention from the main issue.

Division

Assuming that what is true of a whole must also be true of every individual part.

Domino

Claiming that one event will inevitably lead to a series of increasingly extreme events without sufficient evidence.

Double Standard

Applying different rules or standards to similar situations depending on the person or group involved.

Either/Or

Presenting two alternatives as the only possibilities when additional alternatives exist.

Equivocation

Using the same word or phrase with different meanings during an argument.

Etymological

Assuming that a word’s original or historical meaning determines its present meaning.

Every and All

Incorrectly shifting the scope or meaning of universal terms such as “every” and “all.”

Exaggeration

Overstating evidence, claims, consequences, or characteristics beyond what the evidence supports.

Excluded Middle

Incorrectly assuming that no possibility exists between two opposing alternatives.

False Analogy

Assuming that because two things are similar in some respects, they must be similar in other relevant respects.

False Balance

Presenting opposing positions as equally supported when the evidence strongly favors one side.

False Cause

Incorrectly concluding that one thing causes another.

False Dichotomy

Presenting only two possible choices when more possibilities actually exist.

False Dilemma

Forcing a choice among an artificially limited set of alternatives.

False Equivalence

Treating two things as essentially equivalent despite important differences in evidence, severity, or circumstances.

Far-Fetched Hypothesis

Offering an unusual or implausible explanation without first adequately considering simpler explanations.

Faulty Comparison

Comparing things on an irrelevant or misleading basis.

Faulty Generalization

Drawing a broad conclusion from evidence that is insufficient, biased, or unrepresentative.

Faulty Motives

Assuming that because someone has a particular motive, their argument must be false.

Formal Fallacy

Making an error in the logical structure or form of an argument.

Four Terms

Using four distinct terms in what should be a three-term categorical syllogism, making the reasoning invalid.

Gambler’s Fallacy

Believing that previous independent outcomes change the probability of a future independent outcome.

Genetic Fallacy

Judging a claim based on its origin rather than on the evidence supporting the claim.

Group Think

Allowing pressure for group agreement to suppress critical evaluation of alternatives or contrary evidence.

Guilt by Association

Rejecting a person or argument because of its association with someone or something viewed negatively.

Hasty Conclusion

Reaching a conclusion before enough evidence has been considered.

Hasty Generalization

Making a broad generalization from too few or unrepresentative examples.