A Razor is a rule of thumb used to eliminate unlikely explanations.

  • Occam's razor: Simpler explanations are more likely to be correct; avoid unnecessary or improbable assumptions.
  • Hanlon's razor: Never attribute to malice that which can be adequately explained by stupidity.
  • Hitchens's razor: What can be asserted without evidence can be dismissed without evidence.
  • Hume's guillotine: What ought to be cannot be deduced from what is. "If the cause, assigned for any effect, be not sufficient to produce it, we must either reject that cause, or add to it such qualities as will give it a just proportion to the effect."
  • Alder's razor: If something cannot be settled by experiment or observation, then it is not worthy of debate.
  • Sagan standard: Extraordinary claims require extraordinary evidence.
  • Popper's falsifiability principle: For a theory to be considered scientific, it must be falsifiable.
  • Grice's razor: As a principle of parsimony, conversational implications are to be preferred over semantic context for linguistic explanations.