My good friend, Delores Green asked me about this one a few weeks ago. There are several ways “No earthly” is used in speech (idea, means, purpose or reason).

This simply means ‘no conceivable…’ as it is derived from relating to earthly means of thinking.

It is impos-

sible to tell exactly who first used this expression.

The earliest known citation to a form of this is in the Dissertation in The Lusiad; Or, The Discovery of India: An Epic Poem by Luís de Camões, translated into English by William Julius Mickle, published in London, 1778:

“In the first book, Jove summons a council of the Gods, which is described at great length, for no earthly purpose but to shew that he favoured the Portuguese.”

Here it could be said that ‘no earthly purpose’ was used because the council was said to have taken place in the heavens, thus it may be a literal application. But in 1832, a clearly figurative example showed up in Trials of the Persons Concerned in the Late Riots, Before Chief Justice of Great Britain, page 10:

“…where he (the Mayor) could have no earthly idea whether the military assistance was required at that precise time or not…”