“I know I'm intelligent because I know that I know nothing.”

“I know that I am intelligent, because I know that I know nothing.”

“I only know that I know nothing”

“As for me, all I know is that I know nothing.”

“One thing only I know, and that is that I know nothing.”

“Well, although I do not suppose that either of us know anything really beautiful & good, I am better off than he is- for he knows nothing & thinks that he knows; I neither know nor think that I know.”

“As for me, all I know is that I know nothing, for when I don't know what justice is, I'll hardly know whether it is a kind of virtue or not, or whether a person who has it is happy or unhappy.”