In order to describe the corresponding man, Socrates must explain the difference between necessary and unnecessary desires. Necessary desires are those we cannot train ourselves to overcome, the ones that indicate true human needs (e.g. the desire for enough sustenance to survive). Unnecessary desires are those which we can train ourselves to overcome (e.g., desire for luxurious items and a decadent lifestyle). The oligarchic man is ruled by his necessary desires, but his son, the democratic man, is soon overcome by unnecessary desires. Whereas the father was a miser who only wanted to hoard his money, the son comes to appreciate all the lavish pleasures that money can buy. Manipulated by bad associates, he abandons reverence and moderation and begins to regard anarchy as freedom, extravagance as magnificence, and shamelessness as courage. When he is older, though, some of his virtues return and he is sometimes pulled toward moderation. Yet he thinks all pleasures (those of moderation and of indulgence) are equal, and he yields to whichever one strikes his fancy at the moment. There is no order or necessity to his life.
In the last stage of degeneration, democracy, the most free city, descends into tyranny, the most enslaved. The insatiable desire for freedom causes the city to neglect the necessities of proper ruling. The drones stir up trouble again. In the democracy, this class is even fiercer than in the oligarchy because they usually end up becoming the dominant political figures. There are two other classes in the democracy other than the drones: there are those who are most naturally organized and so become wealthy, and then there are those who work with their hands and take little part in politics. The drones deceive both these other classes, inciting them against each other. They try to convince the poor that the rich are oligarchs, and they try to convince the rich that the poor are going to revolt. In their fear, the rich try to limit the freedoms of the poor and in so doing come to resemble oligarchs. In response, the poor revolt. The leader of this revolt—the drone who stirs up the people—becomes the tyrant when the poor people triumph. He kills all the good people for fear that they will supplant him, then enslaves everyone else so that he can steal from them to support his lavish and extravagant life-style. He also needs to constantly make war, to distract people from what he is doing. He must pander to the worst segments of society—the other drones—to make them his bodyguards.
Socrates ends Book VIII without giving us the portrait of the corresponding man. This long psychological portrait is saved for the next book.
Plato’s critique of democracy is insightful and thought-provoking. His description of democracy’s single-minded pursuit of freedom at the expense of other goods, and of the sort of men who tend to gain power in such a system, should give us pause. We must take these criticisms seriously when considering just how we want to judge Plato’s own system. Is the loss of personal freedom really beyond sacrifice? Or might we actually be better off giving up freedom to gain order and harmony in return? In either case, we now know what Plato would say to us when he saw our terror at giving up our sacred liberties: he would tell us that we only cling desperately to our personal freedoms because our soul is disordered and unhealthy, our priorities skewed. We shrink from the idea of living in Plato’s Republic because we are driven by the wrong desires—by the desire for money, physical pleasure, and honor. He would add that if we were driven by the correct desires, the desire for truth, order, harmony, and the good of our society as a whole, we would be more open to adopting Plato’s system of government.
Explaining why the just city must inevitably degenerate over time Plato appeals to a myth. He calculates a number which he calls the “human number” and explains that this number controls better and worse births. Since the rulers will not be perfectly aware of the mathematics involves in calculating this number, they will inevitably make mistakes and mate at the wrong time. The next generation will be inferior to the previous, and rulers will be lacking.
The human number is probably supposed to represent the human good, the Form of the Good as applied to human beings. The Forms and the laws of the universe are mathematical. Just as there are mathematical formulae that describe the movement of the planets and stars, there are also mathematical formulae that describe all the aspects of man. Plato recognizes that there is no one actual number in the case of man or of the cosmos that perfectly sums up all these formulae. He believes that all aspects of reality can be expressed mathematically, and that this mathematical expression of man, space, and time is at least one part of the absolute, transcendent reality of the Form of the Good.