Hanlon's razor
A corollary of Finagle's law, Hanlon's Razor reads:
The derivation of the common title "Hanlon's Razor" is unknown; a similar epigram has been attributed to William James, amongst others. One possible derivation is from the similarity to Occam's Razor. The website Status-Q attributes it to one Robert J. Hanlon who seemingly contributed it to a book about Murphy's law.
A similar quote appears in Robert Heinlein's 1941 short story Logic of Empire: "You have attributed conditions to villainy that simply result from stupidity." It is often asserted that the term "Hanlon's Razor" is a bastardization of "Heinlein's Razor."
This maxim is also widely attributed to Napoleon Bonaparte.
General observations on the predominance of human error over malice occur in various works of literature; Goethe's The Sorrows of Young Werther (1774) mentions: "[...] misunderstandings and neglect create more confusion in this world than trickery and malice. At any rate, the last two are certainly much less frequent."
Hanlon's Razor is a particular favorite of hackers, often showing up in sig blocks, fortune cookie files and the login banners of BBS systems and commercial networks.
A common (and much more laconic) British English version of this law is "Cock-up before conspiracy".
Howard Tayler points out, however, that this only applies when there is no actual malice.