Much of Plato's reasoning for philosopher-rulers centres around his belief that society should be rational and just. It would be important to note that "justice" as referred to by Plato in his work and by other philosophers at the time, does not directly compare with the modern meaning. "Justice" as it was then, was more what today we would call "righteousness" or "goodness". The aims of this essay are to examine the reasons behind Plato's beliefs and the extent to which they are justifiable for the modern day as well as for ancient Greece.
Much of Plato's work is written in the form of dialogues, with Socrates, Plato's tutor, cast as the main character. It is sometimes not clear, "where Socrates finishes and Plato begins". However, concerning the subject of philosopher-rulers, I believe this distinction is not necessary. References to Socrates, especially regarding Republic, can be taken as Plato's beliefs expressed through the character of Socrates and not the man himself. It is also important to note at this time, that the poleis (singular polis), or city-states, were nothing like the modern day "city". The closest modern comparison would be the nation-state and not the city. .
This essay will first see Republic as a discussion of justice. Plato's conclusion of justice led him to differentiate individuals" souls into three parts that he relates directly to the polis. This will be examined along with some of the criticisms offered. Following from this, Plato's "theory of forms", its basis and conclusions as well as its distinction from Aristotle's views, will be discussed. Once Plato's theoretical basis is laid down, the structure he applies to his state will also be considered. This uses the "three-parted soul" as a framework, the polis being split into three "tiers" with philosopher-rulers at the top. Reasoning, practicality and criticisms of this are all discussed. The structure of the state is very important to the topic and Plato's views of family life and children will be looked at, how they may seem authoritarian particularly when modern comparisons are made.