The phrase may have originated in 17th-century slang, when a horse symbolized hard work. A "dead horse" came to mean something that had become useless. In gambling, "playing a dead horse" meant wagering on something, such as a hand of cards, that was almost sure to lose. In a 17th-century quote from a collection of documents owned by the late
Earl of Oxford, Edward Harley, Carrying out that work was said to be "working for a dead horse", since no additional benefit would be gained by the labourer when the work was complete. Many sailors were paid in advance for their first month's work. In his book
Old England and New Zealand, author Alfred Simmons gives a detailed explanation and background of the "Flogging the Dead Horse" ceremony, performed by a ship's crew at the end of the first month of their voyage at which time wages resumed. The sailors would get paid in advance of leaving the harbour, spend their money, and embark the ship with nothing. This situation allowed them to exclaim that the horse, symbolising their usual hard work and without money for motivation, was dead. However, once a month had passed, the sailors would have reached the
horse latitudes, where wages due and paid would prompt the horse to “live” again. One of the earliest synonyms may be found in an ancient Greek play by
Sophocles,
Antigone, == Criticism and proposed replacement by PETA ==