Socratic Paradox/Paradox 1

Paradox
was supposed to have said:
 * I know nothing at all.

In which case, how does Socrates know that he knows nothing?

Resolution
If he knows that he knows nothing, then it is false that he knows nothing, because there's (at least) one fact he has knowledge of: his lack of knowledge.

Hence I know nothing at all must always be false, whoever utters it.