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 theexperience 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.
Socrates' brief conversation with Cephalus is only apparently innocuous; this exchange actually foreshadows several aspects of the just life and the establishment of the just state that will be attempted in the duration of the argument for the Republic.
During Plato's time, Greek thinkers had already established the idea that the good man possesses four cardinal virtues: courage, temperance, justice, and wisdom. In Cephalus, Socrates seems to have met a man who, through the experience of age, seems to have achieved the virtue of courage in that one's denial of the passions (one of which is boundless sexual appetite) requires a kind of courage perhaps surpassing physical courage in combat; in learning to temper his passions, he has achieved temperance. At the same time, Cephalus seems to have attempted to achieve justice in that he tells the truth and repays his debts, and he has tried to think his way through to achieving right conduct and, perhaps, the good life. But as soon as it becomes clear that Socrates has an intricate philosophical subject in mind (the attainment of justice and the establishment of justice for all), Cephalus excuses himself from the conversation: It is plain that he does not pretend to be a philosopher (to love knowledge for its own sake), and, having achieved knowledge, to have achieved wisdom.
Socrates has made it plain in the dialogue that we have not achieved justice because we have not even been able to define justice. Cephalus, in retiring from the conversation in order to sacrifice to the goddess, may be said to be rendering a kind of justice to the gods. But in the dialogue, it is clear that we cannot have achieved justice because we have not thus far been able even to define justice.
the Piraeus Athens' port on the Saronic Gulf of the Aegean Sea; now a city, Piraeus (or Peiraeus).
Thracians natives of the ancient country of Thrace (or Thracia) on the Balkan peninsula, which extended to the Danube.
"the goddess" i.e., Bendis, the Thracian Artemis (the goddess of the moon, wild animals, and hunting, in classical Greek mythology; identified with the Roman goddess Diana).
Sophocles (496?-406 b.c.) Greek writer of tragic dramas.
Pindar (522?-438? b.c.) Greek lyric poet.
Simonides (556?-468? b.c.) Greek lyric poet.