Logic: The Art of Thinking



Fallacy - an incorrect argument
 an argument which violates one of the rules for correct reasoning.

- an argument which no reasonable person should be convinced to accept.

To Commit a Fallacy - to accept an argument which contains a fallacy or to accept fallacious reasoning.

To Be Guilty of a Fallacy - to deliberately use a fallacious argument in order to persuade or convince someone.

Note: Fallacious arguments may have conclusions which are true but their fault lies in the pattern of reasoning used to lead to or support that conclusion.


Accent: ambiguity arising from special stress of words in a sentence, misquoting, taking act of context,

emphasizing or shifting.

Accident: application of a generalization to a case that it is not intended to cover. Also known as Sweeping


Ad Hominem: See Argumentum ad hominem.

Affirming the Consequent (formal fallacy:Y argument of the form:

If p then q . q./~ p.

All-or-Nothing fallacy; see black-white fallacy.

Ambiguity, fallacies of: fallacies depending on shifts in sense within an argument; includes accent,

amphiboly, and equivocation.

Amphiboly: Ambiguity of grammatical or syntactical construction.

Argumentum (Argument appealing to)

ad bacullum: See Force, appeal to.

ad metum; (fear) scare tactic, see consequences

ad consequentiam: see~conseguences, appeal to.

ad hominem: argument attacking the arguer rather than the arguments; includes the following special cases.

1. Ad hominer abusive: argument that an opponent's view is incorrect because of some personal

defect of the opponent.

2. Ad hominen circumstantial: attack on a claim on the ground that the opponent is prejudiced

in the question because of his special circumstances.

3. Tu quoque: defense of a claim on the basis that your opponent has himself made the claim or acted

in accord with it or could not do any better.

4. Psychological Attack:critique of argument based upon critique of motives of arguer (psychoanalyzing)

ad ignorantium: see Ignorance appeal to.

ad misericordiam: see `Pity, appeal to.

ad populum: see "Gallery, appeal to the:  also ~appeal to the people the mob( bandwagon)

ad captandum Vulgus: appeal to popular prejudices

ad superbiam: appeal to pride

ad verecundiam: see Authority, appeal to

Assumption of an irreversible order: confusing correlation with a cause.

Authority, appeal to: argument from the fact that a purported authority supports a claim to the truth

of the claim.

Bandwagon appeal: argument that a view X is ~orrec't because everybody thinks so or that doing' Y is right

because everybody does' it ( sometimes included under appeal to the gallery).

Beard, the; argument from difficulty in making a distinction precise in all cases to the  impossibility of applying the distinction in any case.

Begging the Question: argument that assumes what is to be proved; using a premise whose acceptability presupposes the acceptability of the conclusion; circularity in an argument that is hidden by verbiage.

Big Lie, fallacy of the : argument from a statement's having been repeatedly asserted to the conclusion that there must be some truth in the statement, or from a statement that at first appears so obviously false yet the arguer not irrational to the conclusion that there must be some truth to the statement.

Black and White fallacy: argument that assumes that alternatives are exhaustive when they are not.

Circular Argument: (special cases of begging the question):

argument of the pattern: A because of B of C because of

....because of A.

Complex Question: use of a question that imposes a presupposition onto any answer.

Composition: argument based on the assumption that what is true of the part must be true of the whole.

Confusing Necessary with Sufficient Conditions

Consequences: argument based on the assumption that a view should be accepted (or rejected) because it will lead to good (or bad) consequences.

Continuum, Fallacy of: See Beard, fallacy of the.

Converse Accident: attempt to refute an unqualified generalization by means of exceptional cases.

also known as Hasty Generalization based upon too few and exceptional cases.

Denying the Antecendent (formal fallacy): argument of the form if

p then q. 

not ~ not


Dicto Siinpliciter ( a dicto simpliciter ad dictum secundum quid): See accident.

Diversionary Tactics: attacking or supporting a view by shiifting the point in question to a different but psychologically associated one (see Irrelevant conclusion),. attempt to evade the main question by attacking minor points in an opponent's arguments or by restoring to ridicule or irrelevant humor.

Division: argument based on the assumption that what is true of the whole must be true of the parts.

Doubtable Statement: To accept statements at face value which should be doubted given background information.

Equivocation: use' of a term in more than one sense; a fallacy of  equivocation results when the shift in sense

affects the relationship between the premises and the conclusion. Ambiguity of semantical construction.

Exaggeration or Absurd Extension: see Strawman(Strawperson) fallacy.

False Alternative~: assuming that alternatives are contradictories when they are only contraries. (see Black-White fallacy).

False Analogy: an argument from similarities in which the similarities either do not actually hold or

are not relevant to the conclusion in question. overlooking important dissimilarities.

False Cause: inference that A causes B on the basis of inadequate evidence. Also known as post hoc,

assuming the cause, & questionable cause 

False Dilemma: special case of false alternatives in which the disjunctive premise of the dilemma is

false. non-exhaustive alternatives.

Force, Appeal to: attempt to persuade by threats or force.

Four Terms Fallacy: equivocation with regard to one of the terms in a syllogism;

Gallery, appeal to the: argument appealing to popular prejudices.

Gambler's fallacy (Monte Carlo Fallacy); argument that an event that has occurred less frequently than expected in the recent past is more probable in the near future, or argument that proceeds based upon the mistaken assumption that events which are independent become dependent.

Genetic fallacy: argument in which a claim is accepted or rejected on the basis of its source; argument that projects characteristics of origins onto things developing from those origins. 

Generalization: generalizing from insufficient or unrepresentative cases. Also known as converse accident

Hypothesis Contrary to Fact: argument of the patterns if P was in fact related to Q. then if P had not occurred, Q could not have occurred.

Ignorance, Appeal to: argument from the lack of a proof that P is false to the conclusion that P must be true or from a lack of proof that P is true to the conclusion that P must be false.

Ignora: See Irrelevant conclusion. AKA - "Red Herring"

Impromptu Definition: See Persuasive definition.

Inconsistent Assumptions: use of premises that in conjunction form a contradiction; use of a self-defeating principle that is as damaging to one's own view as to one's opponent.

Irrelevant Conclusion: misdirect argument; use of premises that provide support for one conclusion to provide support for a different but psychologically associated conclusion. AKA - Ignoratio Elenchi, "Red Herring"

Jumping to a conclusion: See Hasty Generalization, Converse Accident.

Loaded Question: see complex question:

Logic Chopping: Irrelevant overprecision on a point of logic. (see Diversionary tactics)

Misuse of contradictory Alternatives: assuming that no two alternatives are exhaustive, not even contradictory ones.

Mob, Appeal to the: See Gallery, appeal to the.

Name Calling: attempt to discredit persons holding a view by using abusive language. For example, *Are you going to listen to that effect bleeding heart liberal?"

Negative Proof, fallacy of: special case of ignorance, appeal to.

Non Sequitur (it does not follow): general term for arguments in which the premises, even if true, give no adequate evidence for the conclusion.

Persuasive Definition: Attempt to prejudice the case for or against a view by appealing to a biased definition of one of the basic concepts involved.

Petito Principii: see begging the question.

Pity, Appeal to: argument that a conclusion should be accepted because its acceptance would relieve someone's  misery.

Poisoning the Well: attempt: to discredit an opponent's' source of evidence (See Ad hominem)

Post Hoc (post hoc ergo propter hoc): after this on account of this. See False cause.

Presumptive Proof; see Ignorance, appeal to.

Provincialism: to accept or reject a statement or argument because one identifies with a particular group.

Question Begging Epithet: loaded phrase such as "stodgy conservative "or "bleeding heart" liberal" (see Name calling)

Secundum Quid: See accident

Slanting: Argument based on a biased selection of the available evidence; suppression of evidence that is favorable (or unfavorable) to a view).

Slippery Slope: see Beard, fallacy of the

Slogans, appeal to: appeal to catchy phrases in place of giving reasons.

Special Pleading: appeal to some assumption in attacking an opponents view and then ignoring the consequences that assumption might have for your own view (special case of inconsistency).

Statistical Fallacies

A. Small Sample: Hasty Generalization
B. Data of Different Quality
C. Biased Data: Selective Sample
D. Unknowable Statistics
E. Accidental Correlation

Strawperson fallacy: arguing against a view by attacking an exaggerated or absurd extension of the view. "A special case of irrelevant conclusion. Attacking a misstated form of an argument. a deliberately weakened form.

Tuo quoque: See Ad hominem.

Two Wrong Make A Right: Answering a charge of wrongdoing, not by showing that no wring was done, but rather by claiming others do it too.

Unqualified Generalization: See Accident.

Sweeping Generalization: See Accident.


back to top