The passage on the love between a man and a boy raises the question, what does love have to do with education? Eros, or proper love, is the emotion that motivates us to ascend to the heights of knowledge. As we will see later, true knowledge does not attach itself to the observable world around us. True knowledge, instead, has as its object the realm of the Forms, the universal, eternal truths that only our mind can access. Although study allows us to make the intellectual leap toward this higher realm, eros provides the emotional motivation for studying. For Plato, all action must be motivated by some desire or emotion. The emotional motivation that sends us looking for the Forms, then, is erotic love. Eros is the bridge between the physical world and the intelligible, the motivation for the philosopher’s quest.
According to Plato’s dialogue the Symposium, erotic love spurs us toward knowledge in several steps. We first love the beauty of one physical body. From there, we go on to love two physical bodies. We next move on to the love of all physical beauty, and then to a love of traditions and institutions, to beautiful studies, and finally, to one supreme study, the knowledge of beauty itself. Once we have reached beauty itself, or the Form of Beauty, the journey is complete. We have acheived knowledge and become real philosophers. So the topic of erotic love is perfectly suited to a discussion of education. Erotic love is necessary in the education of the philosopher.
Plato forbids sexual intercourse to enter into these relationships. In the highest sort of love—which leads to knowledge of the Forms—the goal is to lead the beloved to knowledge of truth and goodness. What the lover desires, more than anything, is to improve the soul of the beloved. But this only explains why love should not focus primarily on physical pleasure, not why Plato forbid it.
Plato saw sexual intercourse as serving no useful end. Heterosexual intercourse must be tolerated because it is necessary for procreation, but homosexual intercourse, he believed, serves no end but the fulfillment of physical pleasure. Since homosexual intercourse is useless, it cannot be good or beautiful. Whatever is neither good nor beautiful should be avoided. Second, as Plato makes clear later in The Republic, the health of a man’s soul is determined by the desires he aims to fulfill. A just soul is a soul that pursues the right desires. Desire for physical pleasure is not worth fulfilling. So though the good man, the philosophical man, might have physical desires directed at his young friend, it is crucial to his virtue that he not act on these; he must not try to satisfy his lust for physical pleasure. Instead, he must transmute that erotic desire into a longing for truth and goodness, and a longing to find this truth and goodness together with his beloved.
Now that Socrates has finished laying out the proper education for guardians, he introduces the third and final class of the just society: rulers. The group until now has been called guardians is split. The best from this group will be chosen out as rulers, and only they will now be termed “guardians,” while the rest will remain as warriors and will be termed “auxiliaries,” because their role is to aid rulers by carrying out and enforcing their decisions.
To ensure the right selection of rulers, all the young guardians in training are closely observed. They are made to go through various tests which are intended to determine which of them remain steadfast in their loyalty to the city. They are exposed to various fears and pleasures meant to tempt or frighten them out of their convictions. Those who do best in these tests will proceed on to higher forms of education that will prepare them to rule. The rest, destined to be warriors, will end their education where Socrates left off. The further education of rulers is not discussed until Book VII.