Logical fallacy

Logical fallacies, or logical errors, are erroneous, illogical, or misleading arguments or claims; also called " informal logic fallacies"

• erroneous = contains an error of fact or
• illogical = draws a conclusion not supported by premises
• misleading = deliberately constructed to deceive or mislead

See Social Studies skills: Logical and observational fallacies & paradoxes for list of logical and observational fallacies regarding the Social Sciences.

Logical fallacies and tricks

• also called "rhetorical fallacies"

ad hominem

• a form of "character attack"
  • ad hominem appeals to prejudice and emotions of the audience rather than addressing the opponent's argument itself
  • similar to a "false equivalency" that may include making an argument that "impugns" (insults, denigrates) the opponent's integrity through an association with someone or something else that is otherwise unrelated to the opponent's argument
    • ex.: "My opponent believes in private schools, just like all racists do"
• can be a valid argument:
  • see: Character Attacks: How to Properly Apply the Ad Hominem - Scientific American

ad populum / bandwagon appeal

• argument by exception
  • a fallacy of the particular, in which an argument is attacked based upon a single or rare instance of exception
  • ex.: "We're in a drought"
    • exception: "But it rained the other day"
    • fallacy: just because it rained once doesn't mean the drought is over

association fallacy

• equates having similar ideas or circumstances to a group as being the same as that group
  • ex. "You think smoking is bad. Hitler thought smoking was bad."
• = a type of ad hominem argument

broken leg fallacy

• presents a solution for a problem caused by that or a related solution
• i.e, break the leg, then offer to fix it

circular argument

• argument whose premise is its own conclusion
• i.e., restates the argument rather than proving it
• ex. "She's a great skater because she skates well"

confusing credentials for evidence

• i.e., "98% of dentists recommend flossing"
  • does not provide evidence for the benefits of flossing, just that supposed experts say so

either-or fallacy

• incorrectly argues only two options or possibilities

false equivalence

• illogical comparison of dissimilar subjects
• i.e., comparing "apples to oranges"

genetic fallacy

• fallacy that of the origins of something determine its value
  • ex., the VW was designed by Hitler, and Hitler is evil, therefore the VW is evil

Gish gallop

• rapid use of multiple arguments in order to overwhelm a debate or argument
  • avoids scrutiny of individual arguments
  • named for Duane Gish who spoke rapidly and without allowing the opponent to intervene or analyze each individual arguments
    • "gallap" indicates rapidly running horse
• defense against a Gish gallop is achieved by focusing on only one or a few of the core arguments that would thereby undermined the logical basis of all the others presented in the Gish gallop

ignoratio elenchi

• an argument that misses the point

moral equivalence fallacy

• illogically compares things of distinct moral or ethical dimensions
  • ex., "Any politician that disagrees with me is a Nazi!"

non sequitur

• " Humpty Dumptying" or "Humpty Dumptyisms":
• = an "arbitrary redefinition" like that used by Humpty Dumpty in "Alice in Wonderland"
• who tells Alice, "“When I use a word it means just what I choose it to mean—neither more nor less.”

strawman fallacy

• = the target of an argument (the "strawman") has nothing to do with the actual argument
• weak analogy
• see
  • https://en.wikipedia.org/wiki/List_of_fallacies
  • Fallacies – The Writing Center • University of North Carolina at Chapel Hill (unc.edu)

See also

• Rhetorical analysis