Plato's Republic: The Unjust Soul
Plato does a superb job of stating why an unjust man's soul will be wretched in Book IX of the Republic. His most convincing argument, in my opinion, is his comparison of an unjust man to a city ruled by a tyrant. In Book VIII, Plato, through Socrates, declared his view of the best and worst types of governments for a city. The very best city was one ruled by a king, who rules through wisdom, and the very worst city was basically one ruled by a king gone wrong—a tyrant, who is ruled only by his desires and appetites. In between these are timocracies, juxtaposition by oligarchies, and democracies. The only problem I have with any of this is Plato's assertion that people ruled by a king are happiest. I think the people's happiness is not always greatest in a city ruled by a king, although I do not think this ruins Plato's allegory of a wicked person being similar to a city ruled by a tyrant. Plato begins this argument by telling Glaucon what evil desires inside a man may push a man to do. Any income the man ruled by evil desires has is soon spent (IX, 573, d), and then, naturally, "borrowing follows, and expenditure of capital. (IX, 573, e)" Once the money is spent, the "violent crowd of desires that has nested within his will inevitably shout in protest. (XI, 573, e)" This is much like a drug addict thirsting for a "fix." Once his source of drugs or of money to buy drugs is taken away, he is miserable and wretched, feeling the loss of something that once was. As for a person who has never taken drugs (and is thus not addicted), he would feel no loss were he not able to access drugs. This is because it is rarely the case for someone to miss something they never had the chance to have or never made the choice to have.
Plato goes on to say that now the money must come from somewhere, but raises doubts that even an unjust man would "sacrifice his long-loved and irreplaceable mother for a recently acquired girlfriend" or "for the sake of a newfound and replaceable boyfriend… he'd strike his aged and irreplaceable father. (IX, 574, b)" Glaucon refutes these doubts, as Plato probably had wished him to do. Plato then tells of the chaos in a city ruled by a tyrant or full of tyrannical people, of the theft, murder, intrigue, and violent that these people ruled by their evil desires would beget.
To compare an unjust man to a city ruled by tyranny, Plato calls the evil desire by which the unjust man is ruled the tyrant. The more noble thoughts and persuasions are held captive by this one evil desire. This seems very plausible to me and an apt comparison. Going back to the analogy of the drug addict, surely this sort of person has or once had more just desires and more noble leanings, but now this one thing rules his life. The need for drugs quashes any other thought or desires, rendering them secondary to this one "evil desire" of acquiring drugs. And as the addict becomes used to the drugs, numb to its satisfaction, and immune to its effects, he must either use more of the drug or find a "harder" drug to satisfy this unnatural, "evil" hunger. To me, this seems truly a life of wretchedness and misery. The drug addict's soul is held captive by this one addiction, and thus it is essentially a slave. Therefore, the drug addict is a slave of his own desire, obsessing only over that one unhealthy thing.
Plato states that a tyrannical soul is "poor and unsatisfiable (IX, 578, a)" much for the same reasons a tyrannical city is. I believe that the difference between the tyrannical city's poorness and the tyrannical soul's poorness is that the tyrannical city is focused more upon money and while the people are probably poor in spirit, they certain are poor in money, while, on the other hand, while the tyrannical soul may be poor in money, most likely from pursuing his insatiable hunger, the tyrannical soul is especially poor in spirit because it is not free. Many have stated that it is a fundamental human need to be free and when the unjust man's soul is not, I would say that he is certainly poor in spirit. To address the unsatisfiable part, this is much like what I wrote about in the previous paragraph. The unjust man must have more and more of whatever may satiate his desire, be it erotic love, drugs, money, or what have you, in order to be satisfied. Often this gets to the point where the desire is unsatisfiable simply because it is impossible to acquire the quantities of this satisfying substance in order to simply be satisfied.
This flows into another of Plato's assertions. In paragraph 584 of Book IX, Plato discusses real pleasure. Real pleasure, he states, is not simply relief from pain; that would merely be something Plato would call "calmness." Real pleasure derives from being in this calm state and rising one level above it. What the unjust soul experiences is only "real pain" and "calmness." It never rises from the "calm" state to a state of real pleasure. This is because the unjust soul is held captive by its desire. When the unjust soul is deprived of its desire, drugs, again, for instance, it experiences real pain, referred to as "withdrawal" in addicts. In acquiring its desire, the unjust soul only reaches the "calm" state (before, of course, soon sinking down to the "pained" state again). In this, the unjust man will always be wretched at worst and calm at best, never able to experience true pleasure unless he is able to break free of his evil desire and become just.
These reasons, to me, all seem convincing reasons to accept Plato's argument that the unjust man is chaotic and miserable. The unjust man is always thirsting for his unjust desires and is rarely satisfied. When the unjust man is satisfied, it is merely satisfaction, never true pleasure. To me, this is truly a wretched existence.