The direct democracy of Plato's time lacked a central leader, which left it extremely weak to not only outside forces, but also to internal conspiracy.
Shortly after the return to a democratic society the restored government called for the execution of Plato's friend and mentor, Socrates (accused of corrupting the youth of Athens, and committing acts of impiety, he was tried by the people and executed. It is theorized that his trial was related to a possible affiliation with the Oligarchy of Thirty Tyrants and that this was truly the impious act he was charged with). It comes as no surprise than, that a child of noble birth who came of age during war, and who's mentor was put to death by friends of democracy, would believe that the prosperity of his city could come about through any other means than by absolute authority given to those few who by nature are capable of having it. .
Plato's Republic is laden with references, and opinions of democracy. Through the mouth of Socrates, he speaks of the ignorance of the masses, and the inevitable fall of democracy to tyranny. As the concept of morality is analyzed, a utopian society free of the pitfalls of democracy is created, and its potential as a viable community questioned. .
The backbone of Plato's utopian society is the principle of specialization, the idea that the most efficient society is one that puts each person in the job to which they are best suited. By such a principle, democracy as a form of government is abandoned left only with the option of "professional" rulers. In turn is born the idea of the Philosopher Kings. "The desires of the common majority are controlled by the desires and the intelligence of the minority of better men." In Plato's ideal city these, superior men have undergone enough education and knowledge seeking to know the forms and types rather than the manifestations, the ability to know justice, and hence rule justly.