Posted by ESC on April 27, 2001
In Reply to: "Let the Cat Out of the Bag" posted by yoyo on April 27, 2001
: : During the 17th and 18th Century, corpal punishment was widely used in the miliary and aboard ships to control the crew. The most common pushishment was whipping with a Cat O' Nine Tails (a whip with nine tails usually knoted at the end orwith metal burs on the ends). The Drum Major (or musician) of the troop kept "The Cat" in a bag, tied to his belt. When someone committed an offense, punishable by whipping,it was time for pusnishment it was called to "Let the Cat Out of the Bag."
That one theory. To read others, search the discussion archives under "bag." Here's one explanation posted by Mr. Briggs:
To let the cat out of the bag is said to occur if a secret is revealed. This type of cat is truly furry, unlike that just described. In medieval times piglets were often taken to market in a sack where they were sold. If the purchaser was particularly gullible he was sometimes sold not a piglet, but a cat in the sack. Cats are versatile animals and sometimes managed to escape - the cat was truly out of the bag. In similar manner it was possible to be sold a pup. Incidentally, the sack or bag was correctly termed a poke, hence a pig in a poke. To be sold a pig in a poke was clearly the object of the exercise and why it has come to imply a swindle I can't understand. However, there are other sayings and words which have reversed their meanings over the years. Why this should be so is not understood but this drift of meaning is known as catachresis. A good example of drift is found in the word Brave. In the past it implied cowardice as, indeed, Bravado still does. Incidentally, the diminutive of poke lives on today in modern English in the form of Pocket.