
“Verily we know nothing. Truth is buried deep.”
Another translation: "Of truth we know nothing, for truth is in a well." Diogenes Laertius, Lives of Eminent Philosophers R.D. Hicks, Ed. http://www.perseus.tufts.edu/hopper/text?doc=Perseus:abo:tlg,0004,001:9:11
Source Book in Ancient Philosophy (1907), The Fragments