Razor (philosophy)

In philosophy, a razor is a principle or rule of thumb that allows one to eliminate ("shave off") unlikely explanations for a phenomenon.

Razors include:

• Occam's razor: When faced with competing hypotheses, select the one that makes the fewest assumptions. Do not multiply entities without necessity.
• Grice's razor: A principle of parsimony that prefers conversational implications over semantic context for linguistic explanations.
• Hanlon's razor: Never attribute to malice that which can be adequately explained by stupidity.
• Hume's razor: "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."
• Hitchens's razor: The burden of proof or onus in a debate lies with the claim-maker, and if he or she does not meet it, the opponent does not need to argue against the unfounded claim. "What can be asserted without evidence can be dismissed without evidence."
• Newton's flaming laser sword (or Alder's razor): If something cannot be settled by experiment or observation then it is not worthy of debate.
• Rand's razor: Concepts are not to be multiplied beyond necessity—the corollary of which is: nor are they to be integrated in disregard of necessity.
• Popper's falsifiability principle: For a theory to be considered scientific, it must be falsifiable

See also

• Duck test
• "Extraordinary claims require extraordinary evidence"
• Razor (disambiguation)