Plato on Socrates (and ineffability), from Letter II

 

"Take precautions, however, lest this teaching ever be disclosed among untrained people, for in my opinion there is in general no doctrine more ridiculous in the eyes of the general public than this, nor on the other hand any more wonderful and inspiring to those naturally gifted. Often repeated and constantly attended to for many years, it is at last like gold with great effort freed from all alloy. Let me tell you, however, the surprising thing about it. There are men, and a good many of them too, who have intelligence and memory and the ability to judge a doctrine after examining it by every possible test, who are now old men and have been receiving instruction not less than thirty years, who have just reached the point of saying that what formerly they thought most uncertain, now appears to them quite certain and evident, while what seemed most certain then, appears now uncertain. Consider these facts and take care lest you sometime come to repent of having now unwisely published your views. It is a very great safeguard to learn by heart instead of writing. It is impossible for what is written not to be disclosed. That is the reason why I have never written anything about these things, and why there is not and will not be any written work of Plato's own. What are now called his are the work of a Socrates embellished and modernized. Farewell and believe. Read this letter now at once many times and burn it. So much for these matters." (Letter II 314a1-c6)