The Daily Express, Saturday 23 May, Your questions answered had one about “known knowns” and gave the answer as an ancient Persian Proverb. He who knows not and knows not that he knows not, is a fool. Shun him. He who knows not but knows that he knows not is a child. Teach him. He who knows, but knows not that he knows, is asleep. Wake him up. But he who knows and knows that he knows, is wise; follow him.
Could this have been the basis of the quote made famous in 2002 by Donald Rumsfeld US Secretary of Defense, about lack of evidence re weapons of mass destruction. I think the origin is a poem by Ibn Yamin, a 13th century Persian Tajik poet.
