What is the origin of the expression relating the “cat getting out of the bag”?
The Word Detective has an answer.
Moving to General Questions, because it’s a general question.
The common form is “let the cat out of the bag”. This site discusses two commonly suggested origins.
I’ve read the “pig in a poke” explanation, with the added claim that it arose at a time when Muslim rulers had outlawed sale of pigs (possibly in Spain) so that the animals had to be sold very discreetly, which led to the use of hasty sales in bags, possibly at night.
Having dealt with trapping feral cats, I would have another take. Once you let a trapped cat free, no amount of bait or coercion can make that cat enter the trap again. Once it is free, there is no returning. So to “let the cat of the bag” would be mean that once the secret is out, it can no longer return to being a secret.
I have no cite for this interpretation, but from my perspective it fits the behavior of cats and makes more sense than the pig in the poke variation.
When I was young it was common (or at least commonly thought) to get rid of “extra” kitten by putting them in a bag and throwing them in the lake.
I wonder if this plays into it.
From my experience, you put a paper bag on the floor and the cat always jumps right into it
But they absolutely hate it when you put a sock over their heads.