At the beginning of Book II of the Republic, Plato presents the problem of how to defend justice, not in terms of its alleged benefits to the agent, but in terms of its intrinsic value, as a basis for its benefits. He offers to construct a model to help resolve the problem: an ideal city-state will have the features needed to embody justice, which will then serve as a model for understanding what justice is in the soul. In the latter part of Book II and in Book III, Plato elaborates an ideal state in which there are three classes of people: the workers, the auxiliaries, and the guardians. In Book IV, he makes use of his model to show what justice is in the soul.
Plato begins by noting that legislators need not be concerned with the niceties of laws and the form of government, since a badly governed state will be a mess, while a well-governed state will function properly without much concern for the details. What the ideal state will have is four virtues: wisdom, courage, moderation, and justice, which will come to be known in later times as the Cardinal Virtues. First, wisdom: the city will be wise because it is governed by the guardians, who have years of training in virtue and leadership. Second, courage: the city will be courageous because it is defended by those who are proficient in combat, but more importantly, who understand what is and is not to be feared. The auxiliaries and guardians will focus on what is really important, and will not fear death. Third, moderation: the city has moderation because the desires and passions of the Many are controlled by the wisdom of the Few.
How, then, is justice present in the ideal state? Don’t you see, Socrates asks, that while we, like hunters have been searching for our prey, it has been running around at our feet? What makes the city just is the fact that everyone does his or her own job. The workers produce goods and services; the auxiliaries serve and protect; the guardians lead and govern. When this order is found in the city, everything functions smoothly, and we find peace and harmony. If people from different classes tried to usurp the roles of their fellows in other classes, anarchy and chaos would result.
Now we need to consider the nature of the soul. Does the soul have parts? In particular, does it have three parts like the ideal state? Socrates proposes a test to determine this question. One unified thing will not experience opposites in itself. The presence of opposites is a sign, then, of complexity; and we will find opposites in internal conflicts of the soul. In the soul we find appetites for food and drink. These appetites are not desires for good food and drink, only for food and drink.[19] Here, Plato’s Socrates seems to be abandoning a view of the historical Socrates, found in Plato’s Socratic or early dialogues, that everyone desires the good.[20] Hence, desire for food or drink is, ipso facto, desire for the good. But now Plato rejects the Socratic principle in favor of a more biological account of appetite.
But do humans who are hungry and thirsty always eat and drink willingly? No, we find people who are fasting or dieting who refuse food or drink. This is a case of inner conflict, in this case between a desire for food and drink and an aversion to them. So here, it seems, we have evidence of two parts of the soul that sometimes work in opposition to each other, the appetite and the reasoning part of the soul, which, among other things, calculates what is good and bad for us.
Plato’s Socrates points out another part of the soul, marked by anger and high spirits, that manifests itself in opposition to the other parts. He gives an example of someone who saw a pile of corpses at a place of execution. Part of him wanted to turn away, but part of him wanted to see the lurid sight. He angrily rebuked himself for his weakness, indicating that the spirited part stands opposed to the appetites.
So now we find three parts of the soul corresponding to the three parts of the state. Moreover, we can make a one-to-one mapping here. The appetites are full of desire but devoid of reason, like the workers. The spirited part of the soul is bold and assertive like the auxiliaries. And the reasoning part of the soul is rational and judicious like the guardians. The soul will, then, be wise insofar as the reason rules; it will be courageous insofar as the passionate part does its work; and it will be moderate insofar as the appetites are subordinate to the passionate part and the passionate part is subordinate to the reason. Finally, the soul will be just insofar as each part does its proper work.
In general, then, “Virtue, it appears, would be a kind of health and beauty and vigor of soul, vice a disease and ugliness and weakness.”[21] Glaucon, who is speaking with Socrates, sees immediately that, on this analysis, to act unjustly is to corrupt and damage your soul. You cannot do wrong without destroying your own psychic integrity, without enslaving yourself to your appetites. Even if you are never called to account publicly for your wrongdoings, even if your wickedness is hidden from humans and gods, you are irreparably infected and defiled by your willful abdication of responsibility.
Today we might argue that wrongful action is intrinsically bad and that is all we need to prove. Plato, in accordance with the terms set by Glaucon, wants to show that immoral action is both an intrinsic evil and that it entails evil consequences. But now the consequences will follow inevitably from the corrupt nature of the agent’s soul. A bad soul cannot bring forth good fruits. This was what was to be proved. And now it appears that the challenge has been met and the discussion is over.
Or is it?
[19] Plato Republic IV, 437d-438a.
[20] See Ch. 11.4 above.*
[21] Plato Republic IV, 444d-e.