As Socrates unfolds his city-in-thought, the so-called perfectly just city of the Republic, he speaks of the need for the rulers to promulgate the notorious “noble lie” (414c). The noble lie consists in two parts. First, the citizens are told that their true parent is the earth, that is, the city or polis (414d). This part of the noble lie is designed to promote a kind of sold-out commitment to the polis-a loyalty willing to forsake even the closest (traditional) familial ties. When this aspect of the noble lie is embraced, the citizens view each other as brothers and sisters who are all connected to a common parent, the polis (“Father/Motherland” themes come to mind). Second, the citizens are presented with the “myth of metals.” According to this myth, each citizen is born with one of three kinds of soul: gold, silver or bronze. As you might expect, the citizen’s worth and function in the city is determined by what kind of soul s/he possesses. The myth of metals is created to promote strict class separation and is an attempt to eliminate factionalism. The gold-souled people are best-suited to rule, the silver-souled people (the warrior class) assist the rulers in their plans for the city, and the bronze-souled people are simply to obey. In addition, the classes must never intermarry, as those who “by nature” are superior cannot be tainted by a lower class. For the good of the polis, the bronze-souled people must come to recognize their natural inferiority to the silver and gold-souled classes and be willing to obey and carry out their orders-after all, they are intellectually inferior to gold-souled rulers and cannot properly direct their own lives without the guidance of their natural superiors.
Of course Plato is not giving us a blueprint for an actual city (contra Popper); however, Socrates’ “building plans” strike a similar chord with modern racist projects. (There are, no doubt, significant differences between the two projects; I’m not claiming that a one-to-one correspondence exists. Nonetheless, the commonalities are worth pondering). Drawing from the insights of historian Kenneth Stampp, Floyd W. Hayes III describes the ways in which slave-owners in the American ant-bellum south attempted to “create a good slave.” The following are five common strategies employed by slave-owners in the process of making and managing a slave class.
First, those who managed the slaves had to maintain strict discipline. One slave-owner said, “Unconditional submission is the only footing upon which slavery should be placed.” Another said, “the slave must know that his master is to govern absolutely and he is to obey implicitly, that he is never, for a moment, to exercise either his will or judgment in opposition to a positive order” [Stampp, The Peculiar Institution: Slavery and the Ante-Bellum South, p. 145]. Second, slave-owners thought that they had to implant in the slave a consciousness of personal inferiority. They deliberately extended this sense of personal inferiority to the slave’s past. Slave-owners believed that in order to control black people, the slaves “had to feel that African ancestry tainted them, that their color was a badge of degradation” [to use Socrates’ language, they needed to feel that they were mere “bronze” souls] (ibid.). The third step in the training process was to awe the slaves with a sense of the slave-owner’s enormous power. It was essential, various slave-owners declared, “to make them stand in fear” (p. 146) [following the Republic, to show them the force of the warrior class/silver-souls if they decide to overstep class boundaries]. The fourth aspect was the attempt to “persuade the bondsman to take an interest in the master’s enterprise and to accept his standards of ‘good conduct'” (p. 147) [you must believe our “noble lie” and embrace the solidarity and customs of the city-after all, it’s for the good of the city, which is our Mother]. Thus the slave-owner sought to train slaves to accept unquestionably his criteria of what was good and true and beautiful. The final step, according to Stampp’s documents was “to impress Negroes with their helplessness: to create in them a habit of perfect dependence upon their masters (ibid.)”
 On my interpretation, the city-in-thought is not a kind of blueprint for an actual city. Rather, by showing the impossibility of such a (totalitarian, calculation-oriented) city, Plato highlights the theme of eros (broadly construed as “love”, “desire”, “longing,” etc.) as that which constitutes human existence and which cannot be controlled or managed by mathematics, calculated reason, eugenics etc. In other words, all humans are lovers of something and these various loves, desires and longings are what drive us and direct our lives, actions and decisions.
 Hayes, Floyd W. III. “Fanon, Oppression, and Resentment The Black Experience in the United States,” in Fanon: A Critical Reader. Gordon, Lewis R., Sharpley-Whiting, T. Denean, and White, Renee T. eds., (Cambridge: Blackwell, 1996), p. 16.
 Hayes, p. 16.