Informal Logical Fallacies

Informal Logical Fallacies

1. Formal logical fallacy

   • Flawed argument because of an error in the structure

2. Informal logical fallacy

   • Flawed argument because of an error in the context
   • LINGUISTIC FALLACIES
     • Lack of clarity - using vague/ambiguous terms
     • Fallacy of Division/Whole-part fallacy
       • Characteristics of a whole = characteristics of its parts
     • Fallacy of Composition/Part-whole fallacy
       • Characteristics of parts = characteristics of the whole
       • Stereotypes
     • Fallacy of equivocation/double-meaning fallacy
       • A word/phrase is used in two different ways
     • Pseudo-profundity
       • When a statement sounds profound but really isn't.
   • FALLACIES OF OMISSION
     • Purposely leaving out vital points or misrepresenting certain positions in order to convince listeners of the validity of your argument
     • Fallacies of Bifurcation/black-and-white fallacy
       • The arguer gives only two choices for the listener
       • False dilemma
         • Limits options to three or more
     • Argumentium ad ignoratiam/argument from ignorance
       • Convincing listeners to discredit the subject because of a lack of evidence/proof
       • Shifting the burden of proof
         • The arguer moves the responsibility to the opponent
     • Straw man argument
       • Purposely misrepresent a certain position in order to easily discredit it
     • Reductionism
       • x (a complex issue) is nothing more than y (a simple, vague explanation)
     • The Perfectionist Fallacy
       • You should not try to accomplish a task/goal because you probably will not make it
         • Do not try to do or finish something if you cannot do it perfectly or finish it
       • The end result is more important
     • Fallacy of the Unknowable fact
       • Uses evidence as a fact that cannot be found true or false at the time
   • FALLACIES OF INCLUSION
     • Including irrelevant material to persuade listeners to agree with a claim
   • FALLACIES INVOLVING BUILT-IN ASSUMPTIONS
     • Assumptions about tradition, nature and other people
   • CAUSAL FALLACIES
     • Misunderstanding of cause and effect
   • Fallacies of Intrusion
     • Argumentium ad hominem
       • "argument against the person"
       • Name-calling, slandering, or insulting the opponent
       • Abusive
       • Circumstantial
         • Discredit arguer by implying that he or she has impure/selfish motives
       • Post Mortem
         • Using a famous thinker from the past to engage in ad hominem
       • Verecundiam
         • A false authority figure supports a certain claim (ex. a singer promoting medicine)
       • Baculum
         • Use of threats, punishments, scare tactics to convince listeners
       • Ad populum/democratic
         • Appeals to a group of people's beliefs, tastes or values
       • Crumenam
         • Uses wealth, money, or possessions to validate one's argument
       • Misericordiam
         • appeals to emotions - pity
     • Genetic fallacy
       • Statement, position, or idea is flawed if the source is flawed
     • Tu Quoque
       • Claiming one is a hypocrite or inconsistent to avoid taking that person's position seriously