The quotation first came from a certain Robert J. Hanlon as a submission for a book compilation of various jokes related to Murphy's law published in 1980 entitled Murphy's Law Book Two, More Reasons Why Things Go Wrong.
A similar quotation appears in Robert A. Heinlein's 1941 short story "Logic of Empire" ("You have attributed conditions to villainy that simply result from stupidity"); this was noticed in 1996 (five years before Bigler identified the Robert J. Hanlon citation) and first referenced in version 4.0.0 of the Jargon File, with speculation that Hanlon's Razor might be a corruption of "Heinlein's Razor". "Heinlein's Razor" has since been defined as variations on Never attribute to malice that which can be adequately explained by stupidity, but don't rule out malice. or ... but keep your eyes open. A variant, Grey's Law (influenced, no doubt, by Clarke's third law), posits "Any sufficiently advanced incompetence is indistinguishable from malice."
Leo (July 23 — Aug. 22)
The sky speaks now of a situation which ought to be simple, but has become too complicated. It appears no one but you can untangle the knot. Reaching a certain goal is within your power.
Pisces (Feb. 20 — March 20)
Don't respond to aggravation or feel obliged to get aggressive about what you desire. A stressful exertion is not required. Venus is in your sign. What you need will come sweetly and naturally to you.