5: Reductionist Fallacy

Informal Fallacies

Key Terms

Modus Ponens
Modus Tollens
Disjunctive Syllogism
Reduction Fallacy

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

Fallacies of Cause

  • Deny, confuse, or falsify the cause related to an argument
  • Four types:
    • Reduction fallacy
    • Post hoc ergo propter hoc
    • Texas Sharpshooter fallacy
    • Tautology

Reduction Fallacy

  • An event has a single and simple cause
  • Ignores complexities of an issue for an easier premise to defend or attack


  • There are so many unemployed people downtown. I had no idea so many lazy people lived here!


  • Conclusions drawn from insufficient information
  • Ignores critical elements of an argument in favor of one that is easier to defend or attack