Having now in theory founded the ideal state, Socrates proceeds to try to determine the essential virtues that may be said to characterize it (the Four Cardinal Virtues): wisdom, courage, temperance, and justice. (See Analysis, Book I, Section One) Socrates first seeks to identify wisdom in the state.
Wisdom in the state must be said to reside in the class of rulers, for, by definition, they rule by counseling the other classes and themselves. They are the best of the Guardians, having all their lives been nurtured and educated to assume their place as rulers, and they are the most experienced and oldest of the citizens. It is they who judge their fellow citizens and themselves. The wisdom of the state is found in their counsels.
The second virtue, courage, may best be found in that class which has specifically been inculcated with courage during the entire career of the members of that class: These are the auxiliaries, who in their capacity as soldiers have become, to reflect Socrates' comparison, "dyed in the wool" carriers of courage. The courage of the state is reflected in their very being.
The third virtue, temperance (discipline) is a bit more difficult of analysis because it seems to permeate the other virtues. Temperance is found in the ordering or controlling (tempering) of certain pleasures or desires in the individual; the temperate man is said to be master of himself. If we extend this to the state, in order for it to regulate itself, we see that the state has to run harmoniously. Every class in the state has to cooperate with the other classes; the classes agree with and actively endorse the functions of all classes in the state. Thus the state may be said to be master of itself, in that the three classes will function smoothly as a whole (the state) because of concord and harmony among the classes. The class of rulers, wherein the virtue of wisdom in counsel is to be found, agrees to rule in the service of the other classes and of itself; the ruled classes agree to serve and to be ruled wisely. Thus the virtue of temperance in the state is attained.
Having determined three of the four virtues, only the fourth virtue, justice, remains. We recall that the responsibility of each member of each class is that he attend strictly to the business of that class, that each member fulfill the job assigned him. Since we have determined that each citizen is rewarded within the confines of his class by the very virtue of his patriotically performing his class duty, it follows that no other citizen may by force deprive him of the rewards guaranteed him by his class. When we protect a member of a given class by upholding his "rights" as a matter of course, or we protect him by securing his "rights" in the event that someone attempts, by whatever means, to deprive him of his "rights," then we have effected justice and may recognize it as justice in the state.
In Socrates' further instancing the existence of justice in the state, he argues that a choice example of injustice would ensue if members of a given class, or classes, should by force attempt to seize the "rights" of some other class. However and for whatever cause this forcible violation of class rights might be achieved, if it were to go unreproved, dissension and disharmony would fragment the state. In reproving the evil that is occasioned by the doing of violence to another's rights, justice is attained.
If each member of a given class attends strictly to his own job, and if he recognizes that his rights as a citizen cease when they encroach upon the rights of another citizen, we call this state of affairs a just state.
We may now proceed to demonstrate what it is for a man to be just.
As we noticed quite early in our attempt to define what constitutes the dialogue in hand, or any Socratic dialogue, the method of argument adopted is very like that of a debate. It is symptomatic of a person engaged in systematic thought that he or she perceives that the point under discussion is so general that it would be useful to divide the point of the discussion into more manageable particulars, the better to arrive at logical conclusions about the point of the discussion. In formal discussions having to do with questions brought before legislative bodies of citizens, this method of seeking knowledge about particulars is known as dividing the question, or dividing the motion under debate. This is the method Socrates employs in his discussion of the cardinal virtues. In other words, Socrates' method of thinking, here and earlier, is to divide the discussion of the virtues generally and to seek to define each virtue singly. In so doing, Socrates employs a process of elimination: Having discovered and defined three of the four virtues, it follows logically that the fourth virtue is the one remaining.
As observed in the summary, the various classes of the state must agree to be temperate (disciplined) and to live in harmony with one another. This agreement of fixing harmony-in-the-state is one of the earliest examples, if not the earliest, of what is called Social Contract Theory; it is the theory advanced by philosophers in the Western world throughout its history. Jean J. Rousseau, in France, advances Plato's theory (Du Contract Sociale, 1762), and Plato's theory is reflected in Thomas Jefferson's Declaration of Independence of the United States of America (1776). The citizens of Jefferson's ideal state argue, in a very Socratic fashion, that they number among their rights the right of life, liberty, and the pursuit of happiness. For Jefferson's ideal to be realized, his citizens, like Socrates', must agree that their right to their pursuit of happiness must cease when that pursuit begins to encroach upon the rights of others. The perception of this truth is contingent upon the exercise of temperance and justice, as in Socrates' ideal state.
At this point in the discussion of the ideal state, we should recognize that Plato perceives the state not simply as a random collection of human beings; rather, Plato thinks of the state as comprising a sort of being, a kind of entity in and of itself — we may say a kind of organism. The ideal state, comprised of its various parts (classes), itself possesses the several virtues we have thus far discussed. And we might anticipate, now, that having divided the ideal state into its several parts (in pursuit of the virtues), Socrates may seek the same division in the individual citizen.
smiths i.e., craftsmen, especially metalworkers.
exordium the opening part of a formal oration; here, Glaucon refers to Socrates' long explanation about what he is going to say.