In Book IX of Plato’s Republic, Socrates describes the character of a tyrant. All men, Socrates admits, have a lawless and beastly nature. This darker nature displays itself during dreams while the rational part is sleeping. “Then the wild beast within us, gorged with meat or drink, goes forth to satisfy his desires; and there is no conceivable folly or crime a man may not be ready to commit.” The difference between tyrants and other men is that tyrants do not reign in the wild beast when they awaken, but rather encourage it.
The tyrant becomes a slave to his own desires, especially erotic lust, which Socrates identifies as the most dangerous of all desires. Having spent all that he owns, the tyrant resorts to deceit and force to acquire what he wants. “He must have money, no matter how, if he is to escape the horrid pains of insatiable desire.” A tyrant must also deal with a persistent fear of all those whom he has wronged in his pursuit of irrational pleasures. “He lives in his hole like a woman hidden in the house,” fearful of retaliation for his past wickedness. Thus, the lives of tyrants are full of misery, pain, and fear because tyrants allow their irrational parts to rule over the other parts of their souls.
Besides the clear distinction that Socrates draws between the happy life of the just man and the unhappy life of the unjust man, Socrates offers another demonstration that proves justice is more desirable than injustice. He argues that there are three types of men in the world – lovers of wisdom, lovers of honor, and lovers of gain. Men will assert that the class to which they belong is the best. “The money-maker will emphasize the vanity of honour or of learning if they bring no money with the solid advantages of gold and silver. The lover of honor will think that the pleasure of riches is vulgar, while the pleasure of learning, if it brings no distinction, is all smoke and nonsense. And the lover of wisdom will set other pleasures at nothing compared to the pleasures of learning and knowing the truth.” How are we to determine which class is correct? Which class truly represents the best life?
Socrates argues that there is no better judge than experience. For example, a man who has tasted pizza from Pizza Hut, Domino’s, and Papa John’s will be a better judge as to the quality of each company’s pizza than a man who has never tasted pizza. Similarly, the man who has the greatest experience of the pleasures of wisdom, honor, and gain will be the best judge as to which of the three classes of life is best. Socrates concludes that the best judge of the three classes is the philosopher; “for he has of necessity always known the taste of the other pleasures from his childhood upwards. But the delight which is to be found in the knowledge of true being is known to the philosopher only.”
Rather than merely rely on the word of philosophers, Socrates resolves to prove that the pleasures of the rational part of the soul are more pleasant than those of the other two. First, he asserts that the pleasures of the appetitive and spirited parts of the soul are not really pleasures at all, but rather cessations of pain. For example, when a man is hungry, he feels pain. When he eats, he eliminates the pain of hunger. But this, according to Socrates, is not true pleasure. “Men, not knowing true pleasure, err in contrasting pain with the absence of pain, which is like contrasting black with grey instead of with white.”
Furthermore, the false pleasures of the appetitive and spirited parts of the soul are transitory and less real than the pleasures of the rational part. Food, drink, and honors provide temporary relief from the pains of hunger, thirst, and vanity. Such pleasures exist within the realm of becoming and are necessarily less real than those that exist in the realm of being. Truth, wisdom, and knowledge – being concerned with and derived from the realm of being – provide true, constant, and everlasting pleasure.
Finally, Socrates presents one more metaphor to solidify his notion of the tripartite soul in his audience. He describes man as part human, part lion, and part multi-headed beast. To be noble means that the human part of man subjects the beastly parts to its command; to be ignoble means that the beastly parts of man subject the human part to their commands. “Then how would a man profit if he received gold and silver on the condition that he was to enslave the noblest part of him to the worst? Who can imagine that a man who sold his son or daughter into slavery for money, especially if he sold them into the hands of fierce and evil men, would be the gainer, however large might be the sum which he received? And will any one say that he is not a miserable caitiff who remorselessly sells his own divine being to that which is most godless and detestable?”