Adeimantus and Polemarchus persuade Glaucon, and also thereby Socrates, to remain in the Piraeus, at the house of Cephalus (father of Polemarchus). Cephalus is the wealthy, old metic from Syracuse. A “metic” was a stranger to Athens, not a citizen but one who pays taxes and is not granted civil rights. At any rate, upon arrival at Cephalus’s home, they find another group of foreigners, most of whom remain silent throughout the dialogue, excluding a rhetorician named Thrasymachus. Among the others was Lysias, a classical Athens orator who later played a significant role in the overthrow of the Thirty Tyrants, and also Cleitophon, for whom there is a short Socratic dialogue in which the teaching of virtue by Socrates is compared to that of Thrasymachus.
Socrates notes that Cephalus is very old, seated on a cushion stool, having only just made sacrifices. He is crowned in a wreath. The group goes to sit in a circle around Cephalus. Cephalus represents the old order, or the most natural authority. Cephalus is the center of the discussion, but he leaves the dialogue after it has only just begun, in order to continue making sacrifices and pray to the god. Cephalus does not return in the dialogue.
The unplanned discussion of justice begins with a question from Socrates to Cephalus: ‘Is it a hard time of life’ when one embarks on the threshold of old age? Cephalus begins by disagreeing with his older contemporaries, but he agrees with the poet Sophocles when he claims that old age is preferred because it frees one from the enslaving passions of youth -drinking, sex, and the pleasures of the body. Old age is preferred because it enforces moderation. Cephalus claims that the character of human beings is the just cause of difficulties in age or in youth. If men are orderly and content within themselves, old age is only moderately troublesome. This causes Socrates to be “full of wonder”.
Socrates counters Cephalus by suggesting that many people, or the masses, no doubt claim Cephalus’s ease with old age is not due to character, but rather to his wealth, or his great “substance.” Cephalus agrees, but he also notes that a decent man cannot bear old age in poverty nor in great wealth. We then discover that Cephalus was a moneymaker. He inherited money from his father also. Socrates notes that men who inherit money tend not to value it, but men who earn their money tend to value it twice as much (speaking nothing else but of wealth). Socrates asks Cephalus what the greatest good might be from possessing wealth. Cephalus sees the possession of money as a most worthwhile endeavor for the just and holy man because it makes him not cheat or lie, but also it reassures a man that he is not departing this world with fear of either owing a sacrifice to a god or money to another human being (recall Socrates’s final words about owing a debt to Ascelpius in Plato’s Phaedo). Note that Cephalus answers Socrates’s question with a response that includes an implicit definition of what is just and holy. Socrates only considers the former in the remaining course of the discussion. Cephalus predicates his response on the experience of being close to death, and since all men respond to fear and care, an older man begins to wonder at the stories the poets tell of Hades.
Socrates asks about this simple definition of justice: is it only to tell the truth and to give back what one is owed? Take the example of borrowing weapons from a friend who then demands them back when he is insane -this is, no doubt, an unjust act (i.e. paying a debt of weaponry to an insane man -justice requires a certain degree of common mental health). Before Cephalus can respond, Polemarchus interrupts and defends this first definition of justice. Cephalus departs, laughing while he goes to attend to the sacrifices. Now that Cephalus has left, Polemarchus becomes the heir to the argument. Cephalus does not return.
The conversation on justice begins with piety for the old order, as evidenced by Cephalus, and it turns into a conversation on the passing of age and wealth. In summary: Socrates asks Cephalus about old age, and then about wealth in the passing of age, and lastly about the greatest good of possessing wealth. This leads Socrates to ask Cephalus about his understanding of justice -which, to Socrates, must be good not simply for the giver, but also for the receiver. Therefore telling the truth and paying one’s debts is an insufficient definition of justice, but Cephalus cannot engage the young men on this point, so he leaves in laughter and piety (recall the laughter of Zarathustra as he departs from the old priest in the opening lines of Nietzsche’s Thus Spake Zarathustra).
For this reading I used Allan Bloom’s essential translation of Plato’s Republic, as well as Leo Strauss’s The City and Man and his lectures.