Socrates affirms that he knows only by knowing nothing, in order to deter being inflated by a false sense of his own great wisdom, as proclaimed by the oracle at Delphi. Though many took Socrates to be an expert in the fields in which he questions others, Socrates denies any expertise, and interprets the oracle as saying that the wisest of men are like himself who humbly accept that their wisdom is deficient. Most of Plato’s early dialogue—those that center more on Socrates’ thoughts than on Plato’s own—are concerned with ethical questions, and so we can reconcile Plato’s accounts by saying that Socrates’ wisdom is a kind of ethical wisdom, one that would make him supremely free, upright, and prudent. 

The Delphic oracle, which proclaimed that Socrates was the wisest of men because he knows that he knows nothing, can be posited as the source of Socratic irony. This oracle has led Socrates to assume his highly ironic stance of confessing his own ignorance, and yet showing his interlocutors to be even more ignorant than he; great wisdom turns out, contrary to expectation, to reside in a humble acknowledgment of ignorance. With wisdom of this kind, Socrates does not take himself too seriously. Indeed, his wisdom is deeply humbling, as it casts all pretensions to human knowledge into question. With a smile, Socrates accepts that he is better off the less he thinks he knows and passes this wisdom along with appropriate wit.