It's
"Against stupidity, the Gods themselves contend in vain"

This is a quote from Friedrich Schiller

The first I've heard of it, and what prolly made it famous, was when I read this book by Isaac Asimov, the number one American SF writer, called "The gods themselves". Asimov, is of course a Russian Jew, emigrated to the US at age 3. He's an exponent of the nice kind of Jew, very liberal, unlike those who equalize criticism of West Bank occupation with anti-semitism ...