Why Be Just? The Failure of the City-Soul Analogy in Plato’s Republic

A central question in Plato’s Republic arises at the beginning of Book II: what kind of good is justice, and hence what motivates it? Glaucon challenges Socrates to explain why justice is good in itself, when not accompanied by any of the external consequences of appearing to be just. Socrates attempts to answer this through the analogy of justice in the city and the soul. However, I will argue that this analogy fails to provide an adequate account of internal motivation for justice when moving from the city to the individual soul, and thus fails to adequately answer Glaucon’s challenge. I will begin by examining Glaucon’s conception of justice and the challenge presented in the Ring of Gyges parable. Then I will look at how Socrates develops his ideal city and defines both happiness and justice within it. Finally I will show the fundamental differences between the city and soul that cause the failure of the analogy and Socrates’s attempt to respond to Glaucon’s challenge.

In the opening section of Book II of the Republic, Glaucon puts forward a conception of justice as wholly motivated by its consequences for the individual. He argues that the common conception of justice is as “a mean[s] between what is best — doing injustice without paying the penalty — and what is worse — suffering injustice without being able to avenge oneself” (359 a). Glaucon thinks that we will derive the most happiness by ourselves being unjust to others. This happiness is checked though by other people’s unjust actions to ourselves. So, for Glaucon, it is impossible to achieve the “best” scenario, and justice is a compromise to avoid the “worst” scenario. Underlying this argument is the idea that there is no inherent good in justice in itself. If it were possible to avoid the external negative consequences that come with others being unjust towards ourselves, then it will always be better to be unjust to others than to be just.

The implication of this externally motivated conception of justice is that it is the appearance of justice or the appearance of a lack of injustice that is really good, not the actual justice in itself. Glaucon highlights this point in his description of the parable about the Ring of Gyges (359 c- 360 d). In this story, Gygyes finds a ring that makes its wearer invisible. He proceeds to commit adultery with the king’s wife, and then kills and replaces the king. Wearing the ring has allowed Gyges to avoid any responsibility for his actions. He was able to appear just while actually acting unjustly. This imitates Glaucon’s “best” scenario, where one can commit injustice without having any likelihood of having injustice done to oneself. In other words, with the ring you can avoid any external negative consequences from acting unjustly. There will be no possibility of blame or retaliation. Under Glaucon’s conception of justice there is then no motivation to act justly. Glaucon argues that any person will, given the opportunity provided by the ring of Gyges, act in their own interests rather than justly (360 d). To emphasise this point, Glaucon goes on to describe at length how the actions of two people, one just and unjust, will lead to a situation in which the unjust person is praised for their just nature while the just person is vilified as unjust (360 e — 361 d).

Plato is using Glaucon in this section, supported by Adeimantus, to set up a central question: what is the goodness about justice that motivates us to be just. In other words: why should we be just? Glaucon thinks that there are three forms of goodness that could motivate us. First we could be motivated by things that produce good consequences or avoid bad consequences. Let us call this an “external motivation.” This is what Glaucon thinks motivates us to be just. Secondly, we could be motivated by things that are themselves inherently good. Let us call this an “internal motivation.” Finally, we could be motivated by things that are both good in themselves and produce good consequences. These would have both internal and external motivations(357 b-c). Socrates disagrees with Glaucon’s conception of justice, and instead argues that justice has both external and internal motivations (358 a). Glaucon challenges Socrates to show this.

To explain any internal motivation for justice, Socrates thinks we first need to have a clearer definition of what justice actually is. This question, he thinks, is pre-eminent to any consideration of why we might want to be just. Socrates outlines this at the end of Book I, telling Thrasymachus that “so long as I do not know what the just is, I shall hardly know whether it is a virtue or not and whether the one who has it is unhappy or happy” (354 a). This statement by Socrates brings up another separate, but related consideration in the discussion around justice: the measurability of its value through happiness.

Throughout the Republic, Plato uses happiness as a reference to measure the value of justice. In Book I, Socrates develops this point in order to refute Thrasymachus and demonstrate that justice is better than injustice. Socrates gets Thrasymachus to agree that justice is the virtue of the soul, while injustice is the vice. Then Socrates argues that the just soul will have a good life and the unjust soul a bad one. Socrates connects this to the idea of happiness by arguing that living well, which he equates to having a good life, makes a person happy. From this, Socrates concludes that “the just man is happy and the unjust man wretched” (353 e-354 a). Glaucon and Adeimantus seem to accept this idea and throughout Book II, III, and IV use the concept of this necessary connection between being just and being happy to discuss the nature of justice with Socrates. This is possible even when the brothers disagree with Socrates on the specific nature of happiness, as happens at the beginning of Book IV. This reliance on happiness as a measure of justice will become important later on.

At this point Socrates shifts the discussion of justice, and motivations for it, by drawing an analogy between the city and the individual. Observing that there is justice in both the city and the individual, he goes on to lay out his strategy to discover what justice is and how it can be internally motivated:

“… perhaps there would be more justice in the bigger [the city] and it would be easier to observe closely. If you want, first we’ll investigate what justice is like in the cities. Then, we’ll also go on to consider it in individuals, considering the likeness of the bigger in the idea of the littler…” (368 e — 369 a).

Socrates plans to define the concept of justice in the city and determine motivations to be just in the larger city context, before returning it to an individual context. In this analogy, Socrates generally deals with the city as a closed system, self-sufficient and without needing to interact with external actors like other cities. The only point where he does reference external actors is when describing the need for expansion to build a “luxurious city” (372 a). In this case however, Socrates does not discuss other cities as moral agents deserving justice but only in terms of the realities of needing to defend against them. So throughout the building of the ideal city in Books II and III, Socrates generally makes the city a closed system. This is advantageous because by building a city that does not have to deal with any external consequences, the justice that Socrates finds here must be entirely internally motivated.

So Socrates develops an ideal city where we can discover what justice is. He begins with the idea that a city is built because individuals are not “self-sufficient but [are] in need of much” (369 b). From this idea of mutual support, Socrates develops three distinct classes of people. First the producers who make up the majority of a city’s citizens and are responsible for producing and delivering goods for the city. However, a collection of people need some leadership so Socrates creates the guardian class, responsible for ruling the city. Finally, to protect both from external threats and internal threats to the city, Socrates creates a military class of auxiliaries. In this ideal city, people are allocated to a class based on what they are individually suited for, and cannot move between classes. So a producer could never become a guardian nor could an auxiliary become a producer. This concept of separation is reinforced by the use of the noble lie.

At the beginning of Book IV, however, Adeimantus raises an objection to the ideal city that Socrates has built. In order to protect the protect the city from abuses by the guardians and preserve its separate classes, Socrates introduces stringent limitations to the Guardians personal lives and property (416 b — 417 d). Adeimantus objects, arguing that Socrates is “hardly making these men happy…” (419 a) with his stringent limitations on their lives. Recall that Socrates and Adeimanuts are using happiness as an indicator of justice in the city. So Adeimantus’s objection is really concerned with the presence of justice in the city at all. Socrates responds by asserting that he is not concerned with individual happiness, but rather is “fashioning the happy city — a whole city,” which is where Socrates thinks “we would find justice most” (420 b).

This raises a question about how to measure the happiness of a city. A clear way to measure this happiness would be to simply add up the happiness of individual citizens. This method would give Adeimantus’s objection some weight. Socrates, however, returns to the reason for founding the city — so that each person could take on certain tasks for the mutual benefit of all. Socrates wants to ground the idea of happiness within the different classes that make up the city. So he argues that each class (guardians, auxiliaries, and producers) will be happiest when they do what their class is meant to do. Then “nature [will] assign to each of the groups its share of happiness” (421 c). This answer allows Socrates to disregard the happiness brought to the guardians from their personal possessions, and instead measure their happiness in terms of how their capacity to take up their roles as guardians. It also allows Plato to define the parts of the city in unequal terms. What follows from this argument is that justice is about what each person is capable of, rather than an egalitarian response.

Satisfied with this answer, Glaucon and Adeimantus agree that this city “is perfectly good” (427 e). Having described this ideal city, they endow it with the virtues of wisdom, courage, moderation and justice. Socrates wants to discover justice through the process of elimination; by removing the first three virtues, he argues that what is left in the city will be justice (427 e — 428 a). According to Socrates, the first two virtues are parts of the city, with wisdom being the guardians and the virtue of courage belonging to the auxiliaries. Moderation, however, is unlike the previous two and cannot belong to only a part of the city. Rather, “moderation is like a kind of harmony” (431 e). It is the agreement between classes about “which must rule in the city and in each one” (432 a). Having found wisdom, courage and moderation, Socrates asserts that all that is left is “the power by which all these others came into being; and once having come into being it provides them with preservation…” (433 b). So Socrates brings back the idea that the city was founded in order that individuals could take on specific tasks and support each other. This is what is left, and hence must be justice. The idea “that each one must practice one of the functions in the city, that one for which his nature made him naturally most fit” (433 a). So justice is doing one’s own part and minding one’s own business. Notice that this conception of justice is the same as Socrates’s conception of happiness in the city, which is meant to serve as an indicator of justice. Like in Book I, they become mutually inclusive.

So within the city, justice is being well-ordered and balanced, where each group keeps to themselves and does what they are best at (though not necessarily being equal). The internal motivation for justice follows directly from this. Socrates has created a city in which happiness is achieved by doing what one is good at and minding one’s own business. This ideal city also creates the ideal conditions for each individual to fulfil their role fully. Imagine a citizen in this city came upon the Ring of Gyges. Now in Socrates’s city, they would have no need of behaving unjustly, because they can secure their ultimate happiness by minding their own business, and playing their part in the city. So in the ideal city there is an internal motivation for justice.

The issue arises when Socrates relies on the analogy between justice in the city and justice in the soul to explain the internal motivation for justice in the individual. He completes the analogy by positing that the soul, like the city, is split into three parts (441 e). Like the city is governed by the guardians, the soul is ruled by reason. This works together with our passions to subjugate our appetites. So Socrates concludes that justice in the individual is the well-ordered or balanced soul. Much like how the classes of the city are separate, but not equal, the just soul also has an unequal structure between its parts.

However, consider that this just person with a balanced soul discovers the Ring of Gyges. Will they also act in a just way, like the individual in the city? Plato’s provision for internal motivation for justice does not provide a conclusive answer on this. The internal motivation is happiness brought on by balance in the soul. This does not provide any internal motivation for interactions between individuals, much like how justice in the city provides no guidance on interactions between cities. It works in the ideal city where we can reconcile happiness as the internal motivation that explains the actions between individuals and groups. This is because Socrates has set up each group as having different goals for happiness. To be happy, the guardians only need to lead, the auxiliaries to protect, and the producers to produce things. Outside of the ideal city, different individuals can compete for the same goal. Trying to define internal motivations for justice in the soul along the lines of the motivations in the city fails to take into account this consideration.

Socrates has not developed any connection between the happiness derived from balancing the parts of one’s individual’s soul and the happiness derived from acting unjustly when presented with the Ring of Gyges. It is perfectly plausible that one could both balance one’s soul and at the same time act unjustly towards other people. There is no causal connection between balancing one’s soul and one’s interactions with others. While we could posit that some connection between balanced souls and social interactions between individuals exists, this is not a claim that any person in the Republic makes. Plato stops at the conclusion that justice is the well-ordered and balanced soul. This means that he has not fully developed an internal motivation for justice and has not solved the problem presented by the Ring of Gyges. So Plato fails to answer the question which he set up in Book II, and provide an adequate account of internal motivation for justice. This is because of a mistaken analogy between the city and the individual soul and leaves Socrates’s conception of justice open to the Ring of Gyges challenge.

Works Cited:

Plato, & Bloom, A.D. (2016). The Republic of Plato (Second ed.) New York, New York: Basic Books.