Orisgin of phrase? What does rhyming have to do with reasoning anyway?
OED takes it back to 1664. And the phrase was in that cite…
Does the OED give an obsolete sense for ‘rhyme’ that might explain why the two were used together? In The Phantom Tollbooth (Norton Juster, 1961) they’re treated as opposites, representing creativity/language and logic/math.
I would point out that the exact same sentence is used in french (“ni rime ni raison”) . So, not being related to a specific language, I would suspect that at some point it had some obvious meaning for a broad array of people (though it might have been borrowed, of course, but would a language borrow a sentence that doesn’t make sense to its speakers?).
It’s probably not a good assumption to make that educated and literate English writers at any time in the past thousand years didn’t know French very well indeed.
I’ve always heard that it originated as a reference to poetry. The Jabberwockie make no sense (has no reason). But it does rhyme. A poem by Carl Sandburg would make sense, but won’t rhyme. A poem that neither makes sense, nor rhymes would be a very confusing thing and it would be difficult to impossible to figure out what the writer was thinking.
So ‘no rhyme or reason’ came to mean ‘There is no pattern or method I can see, and I cannot figure out what this person was thinking.’
You’re overthinking it. Rhyme is used in this sense as “art,” not specifically as a reference to poetry or to similar sounding line endings.
It’s similar to the phrase “meat and drink,” in which meat is a general reference to solid foods, not specifically to animal flesh.
In current usage, they’re both examples of synecdoche
I wasn’t assuming they wouldn’t understand french, but rather that they wouldn’t borrow a purely french saying if it wasn’t equally meaningfull for them and say, their readers.