Informal Fallacies

In argumentation, formal fallacies are unsound arguments that occur as a result of errors in form. Informal fallacies occur, not as a result of the form of the argument, but because the content produces an unsound argument. Examples of content producing an unsound argument would be a false premise, a circular argument, or an irrelevant argument. Following are selected informal fallacies taken from a classification scheme developed by Alex C. Michalos in Improving Your Reasoning (Prentice-Hall, 1986).

 

Pseudoauthority

Learning from people who are authorities in a subject is a fundamental way of gaining knowledge. However, authorities have presumably gained their knowledge about a subject through extensive training and experience. The validity of arguments or claims that make reference to some authority is dependent upon the legitimacy of the authority. Authoritative claims are fallacious to the extent that the authority relied upon lacks legitimacy and expertise in the subject at hand.

 1. Popular person
To use celebrities and other "popular people" to deliver and bolster claims concerning topics on which they have no special claim to expertise is fallacious.

 2. Popular sentiments
To claim that one's view is correct because it is popular may be fallacious.

 3. Irrelevant authority
To use a recognized authority in one area to bolster claims regarding some different area is often fallacious.

 4. Confident manner
To persuade people to a particular point of view as being correct merely by showing great confidence is fallacious.

 5. Aphorism
An aphorism is a saying, a maxim, or a cliche. Aphorisms are often used as substitutes for real reasons or truly authoritative explanations, and to do so is fallacious.

 6. Self-interest
To argue the legitimacy of a point of view based on one's self interest is usually fallacious.

 

Irrelevant Appeals

Appeals or claims in support of an argument based on factors not relevant to the topic at hand are fallacious.

 7. Force
This fallacy is encapsulated by the aphorism "might makes right." To the contrary, an appeal to force is often used in settings in which no legitimate argument can be mustered in support of a claim.

 8. Pity
To support one's claim by appealing to another's capacity for pity and compassion in the absence of sounder arguments that are on point is fallacious.

 9. Ignorance
To assert that one's particular point of view must be correct because there is no evidence to the contrary.

10. Abusing the person
To attack the defender of an issue rather than the issue itself is fallacious.

 11. Bad connections
To argue that an opponent's point of view is wrong because that opponent keeps bad company and cannot be trusted is fallacious.

 12. Straw man
To fabricate an argument against one's own point of view and proceeding to thrash it as having no legitimacy, thus proving one's own point of view, is fallacious.

 13. Pride
To appeal to people's pride as a basis for winning them over to one's point of view has nothing to do with the legitimacy of one's point of view and is therefore fallacious.

 

Confusion

Fallacies of confusion present arguments that obfuscate or make ambiguous the legitimate issues and claims in arguments.

 14. Equivocation
Equivocation plays on the multiple meanings of words. To use a term in more than one way to bolster one's argument is fallacious.

 15. Humor
To avoid issues or assert questionable claims using humor in order to gain support for one's position is fallacious.

 16. Amphiboly
To use the structure of a sentence in a misleading or erroneous manner is fallacious.

 17. Anger
To avoid issues or assert questionable claims using anger in order to gain support for one's position is fallacious.

 18. Emotional language
To use emotional language in order to make a claim more persuasive is fallacious.

 19. Etymology
To argue that a term must be used in a particular way because it has always been defined that way or that is its derivation is fallacious.

 20. Answering questions with questions
To respond to questions regarding one's position by posing questions in return avoids the issues and is often fallacious.

 21. Misdirection (not from Michalos)
To respond to a question or make an assertion that directs the listener away from the question or argument at hand is fallacious.

 

Faulty Classification

Arguments that seek to win support based on the creation of irrelevant or nonexistent classifications are fallacious.

 22. Golden mean
To argue that the correct or best solution lies roughly half-way between two alternative proposals is potentially fallacious.

 23. False dichotomy
To argue that there are only two contradictory solutions to a particular problem (typically one of which is clearly preferable to the other) is fallacious.

 24. Composition
To argue that what is true of the constituent parts of a whole must be true of the whole is fallacious.

 25. Division
To argue that what is true of the whole must also be true of the constituent parts is fallacious.

 26. Oversimplification
To oversimplify the explanations for claims or arguments is fallacious.

 27. Vague terms
To use vague terms, the meanings of which are unclear or imprecise, to support claims is fallacious.

 

Inductive fallacies

Inductive arguments present conclusions that are supposed to be more or less acceptable relative to the premises of the argument. Inductive fallacies apply the implicit probabilities beyond reasonable bounds to produce unsound arguments.

 28. Hasty generalization
To infer that an entire group possesses a characteristic, after having observed a small and often unrepresentative number of individuals is fallacious.

 29. Accident
To apply some general principle improperly to a single instance of something is fallacious.

 30. False cause
To falsely attribute something as the cause of some event is fallacious.

 31. Gambler's fallacy
To argue that a chance event is more likely to occur at this next opportunity because of its recent failure to occur is fallacious.

 32. Faulty analogy
To argue that two things that are alike in certain respects must therefore be alike in other respects is fallacious.

 33. Central tendency
To inappropriately use a measure of central tendency to characterize individual units of a group is fallacious.

 34. Misleading percentages
To use percentages rather than frequencies or actual numbers in a way that misinforms is fallacious.

 35 Misleading numbers
To use numbers and frequencies rather than percentages in a way that misinforms is fallacious.

 

Political Fallacies

36. End justifies the means
To argue that a goal or objective justifies the use of any particular means is fallacious.

 37. Impostor terms
To use popular or acceptable terms that mask the true objectives or claims supported is fallacious.

 38. Repeated assertion
To attempt to gain support for a claim merely by continuously asserting its truth is fallacious.

 39. Quietism
To argue that something is true because there are no claims to the contrary is fallacious.

 40. Creating doubts
To diminish support for an opposition claim by spreading rumors and innuendo is fallacious.

 

Begging the Question

Begging the question occurs when the issue to be proved is already assumed to be true.

 41. Alleged certainty
To assert that something is true when the very truth of the question is the issue at stake is fallacious.

 42. Question-begging epithets
To attach value-laden terms that betray a point of view regarding the truth of the question at stake is fallacious.

 43. Circular reasoning
To argue a conclusion that is also used in the premise of an argument is fallacious.

 44. Complex question
To ask multiple questions within a single question so as to require a particular response in apparent support of one's claims is fallacious.