The dialogue begins with what is apparently a friendly and innocuous conversation between Socrates and Cephalus, in which Socrates asks Cephalus what he has learned from having lived a long life during which Cephalus has managed to acquire a certain amount of money. Socrates asks Cephalus whether age and the experience of age have taught him anything, whether he misses the sexual appetites of his younger years, and whether the accrual of wealth may be said to be a good thing or a bad thing. Cephalus replies that he is happy to have escaped his youthful sexual appetite (one of many passions he has learned to overcome), that wealth in age provides a man the liberty of always telling the truth (never misrepresenting himself in word or deed), and that one obvious advantage of money is that it enables a man to pay his just debts. Thus it is, says Cephalus, that a man may achieve the good life and achieve justice.
Socrates then concludes that justice may be defined as telling the truth and paying one’s debts. But, he says, what if a friend in a reasonable state of mind were to lend you a sword or a knife and later, in a crazed state, should ask for the repayment of the debt? Ought one to remind a friend who is in a crazed state that he is mad, and ought one to return a sword to a crazy person? The answer is plain: No.
Socrates concludes that telling the truth and paying one’s debts is not necessarily always just. It is at this point that Cephalus excuses himself from the conversation.
