>This got me curious. I always remembered it as a quote from Dr. Johnson "One must never attempt to teach a pig to sing - it accomplishes nothing and it annoys the pig." ( Johnson, of course, would not have hesitated to paraphrase the Greeks and as his audience was classically educated they would have probably known the reference.)

The only "Johnson" I know about are Lyndon B. and some furniture cleaning stuff/auto wax company. US specific common knowledge ?

>I know Twain paraphrases him later, but in Googling this I was reminded that the more recent paraphrasing is attributed to Lazarus Long - the creation of Heinlein.

SF rings another bell as well, and on googling I found references to king of persia and Nasruddin. That one reminds me of Niven & Pournelle's "Mote in God's Eye". So here I am doubting my own memory ;-)

regards

thomas