Plato's Republic and Gulliver's Travels

In The Republic, Plato attempts to define the ideal state as it relates to the tripartite division of the soul.  In this division, wisdom, the rational characteristic of the soul, is the most valuable and important.  In the ideal state the ruling class would be the guardians, those who maintain rationality and will operate according to wisdom.  Each individual "should be put to use for which nature intended them, one to one work, and then every man would do his business" (276d).  This conception of the ideal state is exemplified in Jonathon Swift's Gulliver's Travels, within the society of the Houyhnhnms.  Each member of the society maintains a role which he or she was born into, and according to Gulliver the Houyhnhnms are "wise and virtuous" (Swift, 260).  These two qualities are most valuable to Plato within the ideal state, and are manifest in Houyhnhnm land.

The problems that occur within these "utopias" are the central problems of democracy.  The question that arises is whether or not a state such as either of these is just.  This problem is far too great to understand within the context of these societies, so in an attempt to understand the beneficial aspects it should be realized that if considered without "moral" judgements, these societies could function appropriately.  Plato's Republic has a ruling class called "Philosopher Kings" who make decisions based on reason.  They are chosen for their thinking skills, while the Houyhnhnm seem self-appointed.  The "oppression" of the Yahoos does not seem fair or just, but under a well run ideal state where all people understand their place, it helps the society to function better.  The Houyhnhnms and Yahoos are of different species, and people of current North American society think nothing of oppressing animals and calling it food or clothing.  Again, whether this is just or not does not bear relevance in this argument.  The ideal state as demonstrated in Houyhnhnm land is possible and can have beneficial results, if the rules of reason and rationality are observed. 

Plato appeals to a natural division of labour according to which each individual excels at performing a certain function in society.  According to this theory, if each individual is encouraged by the state to perform the function at which he excels, the entire community will function in a virtuous manner.  This idea is present in the Houyhnhnms, in that:
the White, the Sorrel, and the Iron-grey, were not so exactly shaped as the Bay, the Dapple-grey, and the Black, nor born with equal Talents of Mind, or Capacity to improve them, and therefore continued always in the Condition of Servants 
without ever aspiring to match out of their own Race, which in that Country would be regarded as monstrous and unnatural (Swift, 223).

This division of labour is considered a natural separation as defined by the laws of nature.  These "rules of nature" seem to follow the idea of an evolutionary epistemology, that nature has given each being a certain amount of reason, and those with the most are those who will rule the society through that reason.  With this, it implies the rules of nature are most important, and should be followed as the laws of governance.
The problem with living in an ideal state, as suggested by Plato and implied by the actions in Houyhnhnm land, is that any disruption to the understood "government" will completely disrupt the natural order that is understood.  Gulliver's entrance into the world of the Houyhnhnms signifies a friction of this structure.  In an ideal state the roles and boundaries are naturally defined and a Yahoo is not ever to be considered the equal of a Houyhnhnm.  The cultural relativist would suggest that this order is cultural and should be regarded as such, but Plato's theory was one of a universal concept that should be understood that way.  The Representatives in Houyhnhnm land argue that "such a practice [is] not agreeable to reason or nature" (Swift, 224).  Indeed, in an ideal state Plato says that each "will receive the proportion of happiness which nature assigns to them", and in Gulliver transcending his position of a Yahoo in the hierarchical scheme, he eschews the entire natural order (329c).  Forcing him to leave implies a stronger sense of reason, and not emotion, within the Houyhnhnm.  
Since the structure of the ideal and virtuous state should reflect concerns of order and harmony, all political and social authority should be placed in the guardians, in order to impart wisdom.  The Representatives in Houyhnhnm land do just that.  The maintenance of a virtuous state requires a unanimous understanding of each member's place and position.  Without this understanding the ideal state cannot exist; this is why sometimes the pleasures of the individual must be overruled in favour of the needs of the society.