Socrates establishes three arguments to demonstrate that a man who is just lives a happier and better life than an unjust man.
Socrates takes as his first example the tyrant. It might appear to an immature thinker, or a child, that the tyrant, exercising despotism as he does, is surely a happy man; after all, it is plain that the tyrant can live surrounded by pomp and ceremony and all that wealth can buy. All of his subjects he may treat as objects; he can kill any citizen of his state at whim. But we must remember that the tyrant himself is just as much a slave to his own mad master, his lust, as his subjects are enslaved to his tyranny. The best parts of the tyrant’s soul are governed, tyrannically, by the worst part of his soul, and he can never escape the dark prison of his days. The tyrant, who is never in control of himself, is miserable.
In contrast to the tyrant, the just man is free; he is enslaved to nothing, for nothing in his desires or emotions can captivate him; since his whole life is governed by his reason, he lives a self-controlled life, happy in his knowledge and happy that he knows it.
In initiating his second argument, Socrates repeats his argument that the soul is divided into three parts: reason, the spirited part, and desire. So we must remember that there exist three basic types of men: the man of reason who seeks knowledge; the “spirited” man who seeks honor and success; and the man of desire who seeks gain (wealth) and satisfaction. Remember that the man of reason possesses knowledge of the Forms, hence, Justice. Thus it is that the first man is the just man; the second, the timocratic man; and the third is a sort of mixture of the oligarchic, democratic, and tyrannical man. If we were to ask each of these men if he thought himself to be the happiest of the three, each would probably answer yes. It is entirely possible that each man may have experienced happiness, but only the man of reason could have experienced the happiness of knowledge because he alone of the three possesses it, besides possessing the happiness of the other two men. Thus it is that the man of justice is correct in his judging himself to be the happiest. And it is self-evident that the man of reason is best fitted to judge, since he alone of the three knows Justice.
Socrates’ third argument proves out by his making a distinction between pure (positive) pleasure and illusory pleasure (a kind of pleasure which is reliant upon an antecedent “pain”). Such an illusory pleasure might be that of eating (because we are hungry), or drinking, or, one assumes, any sort of sensual pleasure. But pure pleasure, such as the study of knowledge, is reflective of the pleasures of the soul independent of the body, such as aesthetic pleasures or contemplation of the Forms. And we must remember that the illusory pleasures are merely images; knowledge and its study are real. Thus it is that the just man, secure in his knowledge, is the happiest of men.
At this point in the dialogue, Socrates summarizes his argument for the just man, and he answers the other participants in the debate who had argued that the unjust man would lead the best life so long as he could keep his reputation intact, thus fooling his fellow-citizens.
Now we may behold the unjust man, who has ruined his own life by denying his reason and feeding to surfeit his bestial appetites. Nothing can ever profit him for the evils he has visited upon himself, as well as upon others. A man must learn to govern himself through his exercise of reason, lest he live a life of misery. And if he cannot be guided by his own reason, he should, like the craftsmen in the Ideal State, learn to be guided by the intelligence and reason of others—the philosopher-rulers, who will grant him justice and provide for him a happy and fruitful existence.
