In Plato’s Republic, Socrates attempts to determine what justice is by refuting a number of incomplete definitions. He then contemplates how a perfectly just city would be constructed and how it would work in an attempt to further elucidate the nature of justice. But in doing so, Socrates makes a startling revelation: the concept of perfect justice is a myth that can’t be realized.
Socrates begins his investigation of justice by conversing with Cephalus, the aged, well-off father of Polemarchus. Cephalus has lived his life by one simple principle: don’t steal from and don’t lie to others, which Socrates sums up as “[asserting] that [justice] is the truth and giving back what a man has taken from another” (331d). Socrates points out a flaw in Cephalus’ definition: it is not always just to give back what one owes to someone, nor is it always just to tell him or her the truth. For example, if someone was in an unsound state of mind, it would be clearly unjust to give them weapons they own, and it might also be prudent to withhold certain truths (331c). Thus, Socrates shows that actions that seem to be unjust—lying and withholding personal property—might actually be just under the right circumstances. This suggests that justice must be flexible and adaptable to different situations. Since a limited set of laws cannot adequately express what is just and unjust in all possible circumstances, it follows that justice cannot be expressed as law. In other words, what is just is not the same as what is legal.
Cephalus then hands down the argument to his son, Polemarchus, who attempts to defend Cephalus’ definition of justice by strengthening it. Like Cephalus, Polemarchus asserts that justice is giving to “each what is owed” (331e), but distinguishes between friends, to whom one should do good, and enemies, to whom one should do harm (332d). This definition does not satisfy Socrates either. First, Socrates takes issue with the notion that justice is the act of dispensing benefits and harms, much like a doctor can use drugs to cure or induce sickness or a pilot can use his knowledge to guide or destroy ships (332d-e). If justice was merely a form of art, like the art of medicine or piloting, then justice would only be applicable to a narrow set of situations, banalities that Polemarchus identifies as making war and using money (332e-333b). Socrates thus suggests that justice is not a skill to be applied or disregarded when convenient, but a fundamental principle by which to live one’s life. Justice is not a trade but an all-encompassing virtue.
Socrates also objects to Polemarchus’ superficial categorization of people into friends and enemies. When he asks Polemarchus to clarify how he would distinguish between friend and foe, Polemarchus responds “the men one believes to be good, one loves, while those he considers bad one hates” (334c). Socrates points out that people can make mistakes about whom is good and whom is bad, and in such cases, one would be unjust to just people and just to unjust people (334c-d). Clearly, justice should not harm the innocent, those who are seemingly unjust but actually just. Polemarchus immediately agrees this is a problem and strengthens his definition yet again: “The man who seems to be, and is good, is a friend, while the man who seems good and is not, seems to be but is not a friend,” and likewise for enemies (334e). Setting aside the question of determining who exactly is just and unjust, Socrates identifies another contradiction: it is not the role of the just man to harm others. Just as a musician does not make others worse at making music and the act of heating does not cause cooling, so too does the act of doing good not cause harm. Therefore, the just man should not cause harm to others, even to his or her enemies (335d). Thus, Socrates rebukes retributive justice, the idea that justice is the act of punishing others for offenses. The just person should not seek to make others worse off but to make others more just and good.
Having refuted these flawed conceptions of justice, Socrates is then challenged by rhetor Thrasymachus to prove that justice is actually desirable to the individual. Socrates proceeds to do so successfully, but is still dissatisfied by his work; he has demonstrated that it is good and wise to be just, but has not shown what exactly it means to be just (354b). With Adeimantus, Socrates plots to examine justice by conceiving a perfectly just city. Using the analogy that it is easier to read bigger letters than smaller letters, Socrates posits that it will be easier to perceive justice in an entire city as opposed to one individual; the “likeness of the bigger” shall be in the “idea of the littler” (368d-e). Like conventional cities, the city he goes on to create is based on the specialization of labor, the demand for exotic goods, and the need for defense, but Socrates’ city is otherwise radically different. Through an elaborate caste system, education system, and a “Noble Lie” that abolishes all familial ties, the city indoctrinates its citizens into being perfectly just.
In some ways, Socrates’ just city lives up to the standard of justice he alluded to in his refutations of Cephalus and Polemarchus. Justice in the city is not merely a set of laws; it is resilient, a prescribed way of life for each citizen. The city is divided into three classes: moneymakers, common craftsmen and laborers; auxiliaries, warriors who function as the military; and guardians, the rulers. Citizens are permanently assigned a class at birth under the guise that men are born with certain “metals,” or mannerisms that make them suited to a particular one (415a-c). As Socrates explains in Book IV, the city is wise because of the “good counsel” of the educated guardians (428b), courageous because of the ability of the auxiliaries to preserve the regime, and moderate because it is “stronger than itself” in that the lower classes are subservient to the enlightened, intelligent ruling class (431a-c). Hence the city is just by construction, and this is because “each [citizen] must practice one of the functions in the city, that one for which his nature made him naturally most fit” (433a). Thus, Socrates’ city answers his objection to Cephalus’ definition of justice; justice is dictated by the wisdom of the rulers, not trite aphorisms. Indeed, Socrates notes that “it’s appropriate for the rulers, if for anyone at all, to lie for the benefit of the city” (389b), contrary to Cephalus’ notion that lying is always bad. The just city also answers Socrates’ objection to Polemarchus. Justice in the city is not defined by any particular skill or livelihood; each citizen is just by the mere act of fulfilling their prescribed roles. In Socrates’ city, one does not need to be conscious of the mandate to be just in order to be just.
Yet even Socrates’ perfectly just city comes up short of his own standard. First, Socrates suggests that justice should not harm innocents, but the city’s militaristic policy, caused by its insatiable demand for exotic goods, leads inevitably to the conquest of foreign territories. “Then the city must be made bigger again,” Socrates says, after considering the demand for furniture, perfume, painting, gold, ivory, and other such luxuries (373a-b). As a consequence, the city will go to war to enlarge its riches and do battle with other cities vying to do the same (373d-e). However, it does not distinguish between other just and unjust regimes. Socrates makes a nod toward strategic alliances in Book IV (422d), but he never suggests the possibility of peaceful coexistence or mutually beneficial trade. The city could harm very well harm other just peoples by making war and taking territory, which would clearly be unjust. Second, Socrates suggests that the concept of justice should be flexible and adaptable. The perfectly just city certainly expresses justice in terms of human intent instead of fixed law, but it seems seems locked in a very peculiar state of isolation. Says Socrates, “…the overseers of the city must cleave to this, not letting it be corrupted unawares, but guarding it against all comers: there must be no innovation in gymnastic and music contrary to the established order” (424b). Essentially, the city’s notion of justice is not open to change by artists, poets, or writers. The execution of justice may be flexible, but the idea of justice itself is not. Conventional cities are places of innovation and social change, but Socrates’ just city does not waver from the foundation laid by its founders.
It is interesting that Socrates considers the just city’s demand for luxurious goods, and hence its invasion of other cities, inevitable. “We are, as it seems, considering not only how a city, but also a luxurious city, comes into being. Perhaps that’s not bad either. For in considering such a city too, we could probably see in what way justice and injustice naturally grow in cities,” he says (372e). If even the perfectly just city cannot restrain itself from doing injustice to other cities, this suggests that perfect justice between cities—and hence individuals—is not really possible. And if the perfectly just city cannot accept new ideas because they might destroy the just regime, then this similarly suggests its very impossibility. Societies change as a consequence of technological progress and new ideas that alter the human condition; it’s impractical to maintain a city with an immovable ideology. Ultimately, Socrates’ thesis in the Republic is that the perfectly just regime is incongruous to the human desire to yearn for more.
Plato. The Republic of Plato. Trans. by Allan Bloom (New York: Basic Books, 1968).