In episodes 4, 5, and 6, we have already looked at the key arguments that Plato proposes in The Republic to show the special nature of the Ideal, insofar as it can be shown. As he argues, knowledge of the Ideal is the unique realm of the philosopher, and “Since the philosophers are those who are capable of apprehending that which is eternal and unchanging….” (6.484b), they are the logical candidates to be the rulers of society. He goes on then at some length to describe the nature of this society, which he calls “aristocracy,” or government by the best. (And this was before Downton Abbey!) But later he admits that “since for everything that has come into being destruction is appointed, not even such a fabric as this will abide for all time, but it shall surely be dissolved…” (8.546a) and goes on to describe four imperfect societies, and the types of individuals that make them up.