From World Wide Words: No room to swing a cat

 Questions and Answers: No room to swing a cat

Q From Mindy: I was discussing with my husband the other day the phrases no room to swing a cat and you can't swing a dead cat without ... He related the usual origin of the phrases as referring to a cat o' nine tails, but this sounds suspiciously like a folk etymology to me. Are the phrases really related, and do they refer to felines, whips, or some other cat-like object?

A The second of your phrases, which is variously completed, as "You can't swing a dead cat without toppling a corrupt politician" or "You can't swing a dead cat in the shipping industry without hitting somebody with phoney papers" or "you can't swing a dead cat without hitting a Starbucks", is a modern creation — I can't find an example of it before the late 1980s.

It's almost certainly derived from your other idiom, which is some centuries older. It is indeed frequently said to be from that awful naval punishment. Most reference books say something similar to this entry from the Penguin Dictionary of English Idioms of 2001: "The original phrase was probably 'not room to swing a cat-o'nine-tails', and dates from the time when sailors were flogged on board ship. The floggings took place on the deck because the cabins were too small to swing a cat in."

A nicely summarised explanation, it falls down on two counts.

Ship's cabins were for sleeping in and ship life took place elsewhere; nobody would have even considered a flogging in a cabin because the ship's company would have been mustered to witness punishment. The only place to do that would have been on deck. (The cat-o'nine-tails was also a prison punishment in some countries but similar comments apply; the person to be flogged was tied to a post in the prison yard for other prisoners to observe.)

Secondly, I can't find a case in the English literature databases that I've searched that mentions swinging cats in the context of flogging, or even ships. Your view that the story is a folk etymology is well-based.

The earliest example of the phrase is this:

Moreton is return'd to his old occupation, and Preaches in a little Conventicle you can hardly swing a Cat round in.
Letters from the Dead to the Living, by Thomas Brown, 1702.

Brown was a well-known author and his work was popular in its time, being reprinted on several occasions in the following decades. It may even have been the source, though I suspect not. It doesn't by itself refute the cat-o'nine-tails story, since the instrument was known by that name somewhat earlier (it appears in Congreve'sLove for Love of 1695 and in an English translation of Rabelais that's said to be of 1665, though I can't confirm the date).

Why anybody should want to swing a cat at all is unclear. If they did, then the idiom would have naturally followed. It's this puzzle that leads so many reputable works to suggest the punishment story. Could it have been from some child's cruel game? My guess is that it was just an ingeniously inventive way to say that an enclosed space was especially small.