No good deed goes unpunished

The phrase "No good deed goes unpunished" is a sardonic commentary on the frequency with which acts of kindness backfire on those who offer them.

The phrase is first attested in Walter Map's 12th-century De nugis curialium, in whose fourth chapter the character Eudo adhered to inverted morality "left no good deed unpunished, no bad one unrewarded".

[1][2] Conventional moral wisdom holds that evil deeds are punished by divine providence and good deeds are rewarded by divine providence:[1] For as punishment is to the evil act, so is reward to a good act.

[1] The ironic usage of the phrase appears to be a 20th-century invention, found for example in Brendan Gill's 1950 novel The Trouble of One House.

[5] In 2005, author David Helvarg introduced the concept that the punishment may be a form of retaliation, in a piece he wrote for Grist Magazine, "Remember that sign they hung up in an EPA office during the Reagan administration, 'No good deed goes unpunished'?