“”Never attribute to malice that which can be adequately explained by stupidity
 Guises and corollaries
Hanlon's razor is essentially a special case of Occam's razor. Occam's razor states that, assuming equal explanatory power, the simplest solution (formally, the one with fewest assumptions) should be preferred. Assuming intent is a pretty big assumption, but we all know that (other) people are idiots. The razor is most often invoked in the context of trying to refute a conspiracy theory: where a conspiracy is perceived, with no other evidence available, it is more likely to be ineptitude or apathy than malice that results in the problem.
The statement has also been seen in the guise of "cock-up before conspiracy", based on a statement about the media and government by Margaret Thatcher's press secretary, Bernard Ingham. The Wikipedia rule "Assume good faith" is a nicer rephrasing of this rule, indicating that idiots at least have their hearts in the right place.
The razor also has a corollary in Clark's law (named after J. Porter Clark, and based on Arthur C. Clarke's Laws), which states that "any sufficiently advanced incompetence is indistinguishable from malice". A further observation was made by Alexandre Dumas (fils), commenting on the fact that idiocy is all pervasive, whereas intentional malice tends to go away occasionally. Dumas appeared to be quite sure of which he preferred to happen:
“”I prefer rogues to imbeciles, because rogues sometimes rest.
 More completely
- Never assume malice when stupidity will suffice.
- Never assume stupidity when ignorance will suffice.
- Never assume ignorance when forgivable error will suffice
- Never assume error when information you hadn't adequately accounted for will suffice.
 See also
- Wikipedia on Robert Heinlein
- ↑ But also to Robert J. Hanlon, who was apparently a real person and not just a mishearing of "Heinlein."
- ↑ "Many journalists have fallen for the conspiracy theory of government. I do assure you that they would produce more accurate work if they adhered to the cock-up theory." Brisbane Times - Case of a misplaced point
- ↑ In the original French, "J'aime mieux les méchants que les imbéciles, parce qu'ils se reposent." Or various other renderings, e.g. "Je préfère le méchant à l'imbécile, parce que l'imbécile ne se repose jamais" ("... because the imbecile never rests") or "Si je devais faire un choix, entre les méchants et les imbéciles, ce serait les méchants, parce qu'ils se reposent."
- ↑ It's apparently mentioned in Histoire de la littérature française (900-1900): Le dix-neuvième siècle by Léo Claretie
- ↑ A Yahoo! Answers page suggests it was Dumas' response to Victor Hugo saying "Les méchants envient et haïssent; c'est leur manière d'admirer." ("The wicked envy and hate; it's their form of admiration.")
- ↑ http://lesswrong.com/lw/372/defecting_by_accident_a_flaw_common_to_analytical/31kb?c=1