9: More Fallacies in Debating

Special Pleading & Slippery Slope

Informal Fallacies

Key Terms

Modus Ponens
Modus Tollens
Disjunctive Syllogism
Reduction Fallacy
Post Hoc Ergo Propter Hoc
Texas Sharpshooter Fallacy
Tautology
False Dilemma
Straw Man
Special Pleading
Slippery Slope

  • Not logical
  • Pseudo-reasoning (false reasoning)
  • Unsound arguments

Fallacies in Debating

  • Deny, confuse, or falsify an argument most often in a debate
  • Six types:
    • False Dilemma
    • Straw Man
    • Special Pleading
    • Slippery Slope
    • Meaningless Jargon
    • Weasel Words

Special Pleading

  • Argument that premise is beyond criticism
  • or, Premise transcends our understanding

Example

  • Apollo’s chariot carries the sun across the sky. This has been common knowledge for centuries. No mortal has the ability to understand why or how this occurs. It just is.

Problem

  • Reasonable claims must be justifiable. Anyone can make any sort of claim (e.g. Apollo's chariot carries the sun), but if he or she wants to present a valid argument then the claim must fall within the confines of evidence and reason. Otherwise, it is simply a personal belief and not falsifiable knowledge.


Slippery Slope

  • Asserts an event will have a future negative effect
  • Effects are extreme in nature

Example

  • If we legalize marijuana, millions of people will become addicted to heroin.
  • If You Give a Mouse a Cookie children’s book series by Laura Joffe Numeroff
  • Humorous approach from Robot Chicken Clip

Problems

  • Conclusions drawn from invalid premise or conclusions require a stretch in logic
  • Slippery Slope is impossible to disprove because it predicts the future