Plato grew up in the time of the Peloponnesian War, in which Sparta conquered his city, Athens. Plato believed that societies have three parts: appetite, spirit and reason. The appetite was the productive sector--the workers. The spirit consisted of those who were adventurous and brave. Thus the spirit was the military. The reason consisted of those who possessed the temperament and levelheadedness to make decisions. Since reason was in the head, with the other two parts below it, Plato believed that those who reason well should be at the top and should rule. So Plato--like his teacher, Socrates--believed that philosophers should rule. These views came in part from when a court with democratic rulers as jury decided to sentence his teacher Socrates to death on the charge of impiety and corrupting the young.