Hanlon's razor is an adage, or rule of thumb, that states: "Never attribute to malice that which is adequately explained by stupidity."
A statement similar to Hanlon's razor appears in Robert A. Heinlein's 1941 novella "Logic of Empire". The character Doc in the story describes the "devil theory" fallacy, explaining, "You have attributed conditions to villainy that simply result from stupidity."
Hanlon's razor became well known after its inclusion in the Jargon File, a glossary of computer programmer slang, in 1990. Later that year, the Jargon File editors declared its origin unknown, and wrote that there was a similar epigram by William James; however, it seems that this was a mistaken reference and that they actually meant William James Laidlay, since Laidlay is known to have written a comparable statement. In 1996, the Jargon File entry on Hanlon's Razor noted the existence of a similar statement in Heinlein's novella, with speculation that "Hanlon's razor" might be a corruption of "Heinlein's Razor". In 2002, the Jargon File entry noted the same. The Jargon File now calls it a "Murphyism".
The name was inspired by Occam's razor.
Variations
Grey's law (a humorous parallel to Arthur C. Clarke's 3rd law):
A variation appears in The Wheels of Chance (1896) by H. G. Wells:
A similar quote is also misattributed to Napoleon. Andrew Roberts, in his biography of Winston Churchill, quotes from Churchill's correspondence with King George VI in February 1943 regarding disagreements with Charles de Gaulle: "His insolence ... may be founded on stupidity rather than malice."
See also
- List of eponymous laws
- Finagle's law, anything that can go wrong, will—at the worst possible moment
- Hitchens's razor, assertions made without evidence may be dismissed without evidence
- , do not dispute propositions unless they can be shown to have observable consequences
- Occam's razor, the simplest explanation is often the correct one
- Pareto Principle, roughly 80% of outcomes derive from 20% of causes
- Peter Principle, bureaucratic inefficiency is ubiquitous because employees are promoted to their level of incompetence
- Principle of charity, interpret a speaker's statements in the most rational way possible
- Stigler's law of eponymy, an observation that no scientific discovery is named after its discoverer
- Sturgeon's law, ninety percent of everything is crap