He who knows and knows he knows, and he who knows not and knows he knows not, has knowledge; but he who knows and knows not he knows, and he who knows not and knows not he knows not, is a fool.
The above proverb was learned by the informant from a school teacher in his first year of minor Seminary (i.e. equivalent to high school), who likely repeated it several times in reference to learning. The informant states that the proverb could be used whenever you think any of the four parts is true but that it is most often used when you think the last part is true. It could be said to the person you think it relates to (as in somebody who thinks they truly know something when they really dont), or to someone else. The informant considers this proverb useful because it points out to everyone that they should be aware of what they are doing. Furthermore, it applies to every aspect of life; no matter what you are doing, you should have knowledge about what youre doing and knowledge of that knowledge itself, whether you are buying something, selling something, using something, or whatever.
This proverb seems to be a shorter variation of the following Arabic proverb:
He who knows not, and knows not that he knows not, is a fool. Shun him. He who knows not, and knows that he knows not, is a child. Teach him. He who knows, and knows not that he knows, is asleep. Wake him. He who knows, and knows that he knows, is a leader.
The message of the version given by the informant seems, in general, to align well with that of the more often cited version, though the latter clearly makes a more specific statement about each of the four kinds of person and their respective degrees of knowledge and, more importantly, of self-knowledge (or knowledge about their knowledge). The theme of determining the extent of ones own wisdom or ignorance is a prevalent theme in Western thought, contained everywhere from the famous maxim Know thyself, to Socrates apparent belief that the oracle at Delphi proclaimed him the wisest man in the world precisely because he claimed to know nothing (hence, like the second type in both versions of the proverb, but more so the informants). I agree with the informant that the last section of his version of the proverb is the one that we would most likely have in mind when using this saying, but I believe in general the proverb sets-up a slippery slope; for if one must appeal to a sort of meta-knowledge in order to evaluate his more immediate knowledge, it follows from the same logic that he should continue on so that he not only had knowledge of his knowledge but even knowledge of this higher order knowledge and so forth ad infinitum making the notion of an ultimate form of self- knowledge, and perhaps knowledge itself, impossible.
Walsh, William Shepard. Handy-book of Literary Curiosities. Philadelphia: J.B. Lippincott Company, 1893. 593. Web http://books.google.com/books?id=1zo4AAAAMAAJ&printsec=frontcover&dq=handy-book+of+literary&hl=en&ei=tUy6Tb0ok-SxA_Gd0NkN&sa=X&oi=book_result&ct=result&resnum=1&ved=0CFQQ6AEwAA#v=onepage&q&f=false