This phrase derives from an ancient Greek expression: “to call a fig a fig, a trough a trough”. It is first recorded in Aristophanes’ play The Clouds (423 B.C.), and was also used by Plutarch in his Moralia half a century later .Apparently some scholars believe that both the fig and the trough were originally sexual symbols.
During the Renaissance, the Dutch scholar Erasmus (1466-1536) confused Plutarch’s “trough” with the Greek word for “digging tool” . Later Richard Taverner (1515-1575) compounded the error in Garden of Wysdome (1539) as:
Whiche call a mattok nothing els but a mattok,
and a spade a spade.
(A mattock is another kind of digging tool.)
Charles Dickens then popularised the phrase by including it in Hard Times (1854) when Josiah Bounderby says
There’s no imaginative sentimental humbug about me. I call a spade a spade.