Plato, in the Republic, systematically formulates a conception of an ideal society centered around the form of the Good. All just states must be based on an eternal blueprint of the perfect society, an unchanging, objective model, as opposed to a subjective conception of society that is subject to change based on belief and opinion. Plato insists that the rulers of his state, through the great powers of dialectic, will be able to oversee a society in which all citizens, assigned their proper roles and proper breeding matches, will be happy; these gold souls, through mathematical reason and eventually dialectic, will discover and comprehend the Form of the Good, thus being able to always make correct decisions securing their society. In formulating the intelligible forms as the basis of his society, Plato assumes that the Rulers will be able to apply the principles of the forms to the changing world in which they are reflected, making proper decisiosn; however, Plato is wrong to assume that the Rulers will be able to apply the forms to their own, unique reflection of the ideal society.
In the ideal society elucidated by Plato, the “gold souls” must undergo a fifty-year system of education before ruling, being introduced to dialectic at around age thirty. The ultimate purpose is that the Rulers prove their understanding of the Forms, especially the Form of the Good, before they may be declared fit to oversee society. “Politics”, the structure of government, revolves around the Ruler’s knowledge of the Forms and ability to apply them to society, promoting the general welfare of all citizens. Such an understanding of the Form of the Good is necessary in order that the Rulers have the ultimate knowledge of the proper things to do; just as in the parable of the Cave, in which the common citizens see the faintest shadows of images while select citizens, after a difficult length of time, go outside the cave and comprehend the true sources of the shadows, so too the Rulers must be able to comprehend the true source of physical images (the intelligible forms), in order that they be able to apply eternal, unchanging principles to society. Rulers can’t be the citizens chained in the cave; though their decisions reflect in the changing world of shadows inside the cave (i.e. the physical world), proper decisions may only be arrived at through true knowledge of the roots of the shadows, an eternal truth.
Plato stresses the importance of the relation between the Forms and the structure of society due to his belief in the necessity that the gold souls, the rulers, be concerned with the realm of the unchanging eternal, and not the physical, changing world of belief and opinion. In order for each citizen to be happy, they must occupy their unique place in society as set out to them by the Rulers’ these critical decisions of the rulers, such as the proper breeding matches and proper assignment of a citizens occupation, must be made correctly in order for society to function properly. The true source of these proper decisions, the forms, must be understood completely, and the Ruelers must be completely dedicated to the pursuit of knowledge of these Forms (and must occasionally, albeit reluctantly, determine the images of these forms as they apply to the physical world and society); in order that the best decisions be made, realizing the purposes of a just society (serving the common interst, and making each citizen happy through the subjugation of appetite to reason, or at least subjugation of the bronze souls to the gold souls, who understand what the best interest of each citizen is). Justice, when realized through the form of the Good, no longer remains arbitrary, but rather an eternal set of values that promote happiness for each citizen (for as Plato ultimately proves, the just man is happier than the unjust man).
In linking politics to the intelligible forms, Plato assumes that a prototypical model for society exists, namely his own. His line of reasoning rejects the suggestion that perhaps forms don’t exist for every object, or that perhaps some forms have no true reflection in the real world. Plato claims that his society “is not merely an idle dream, difficult through its realization may be” (540d). In asserting that his society can exist in actual practice, Plato makes key assumptions about the nature of the forms that he describes. However, does a form of an ideal couch, for instance, exist outside the physical world? Does an eternal form of the perfect couch exist, even though its only practical use is in the realm of the physical world. Put more clearly, in the unchanging realm of the eternal, there is no need for sitting on a couch, for such physical actions don’t exist in that realm; so if a form of the perfect couch exists, its only function is to serve as the true source for physical images of couches. To apply this example to Plato’s, that of the form of a perfect society: without people living in a society, a society couldn’t be properly labeled as such. A form of the perfect society, then, is only relevant in the physical world. The forms exist ona different plane of existence; however, why does one need an eternal form of the perfect society if there are no living/dying creatures in the eternal realm? Plato believes that there is a “right answer” to every problem that may be reached via the forms; every solution may be attained through the knowledge of the forms. However, physical reflections of these forms may change. Thus, Plato assumes that not only does a form of the perfect society exist, but also that it ma be linked to one single reflection of that society that can exist in actual practice, i.e. his ideal state. In describing the relationship of the intelligible forms to politics, Plato believes that one physical society exists that reflects the ideal form of socity. Plato’s assertion that his society actually exists in the physical is problematic, for though he is correct in searching for an ideal society that would make everyone happy, he assumes that such a society can function according to its ideal. An appropriate analogy to Plato’s society might be the difference between communism in ideal and communism in practice, as an example. Communism exists perfectly well in theory, a society in which every citizen is equal, and contributes “each in according to his ability, each in according to his need”; yet the 20th century never revealed any actualization of this ideal, as communist societies (for instance, the Soviet Union and Cuba) degenerated into totalitarian dictatorships. Plato’s ideal gold soul, with all of its sterling mental and ethical characteristics, may not exist; even if such Rulers do exist, and are capable of Comprehending the Forms, they most likely will be unable to apply those forms to the changing world. Plato’s idea of eugenics and the proper breeding formula serves as an illustrative example. Admittedly, these conceptions are foreign to the modern mind; accepting that a formula exists, however, it would need to be modified in conformance with the characteristics of the citizens comprising his society. every human being is different; two different ideal societies would possess different characteristics, as two different reflections of the Form of the Good; the gold souls, while knowledgeable of the Forms, would be ignorant of the method to apply the notions of the intelligible forms to their own unique reflection. In practice, every ruler might not arrive at the correct decision appropriate to their own society. The physical reflections of the forms are manifested in a physical world, subject to change; the Ruler’s application of the principles derived from the forms exist in the world of opinion/belief as well, so though Plato’s conception of the perfect society exists in the ideal, theoretical world, it most likely does not reflect into a practicable society.