Change in the political condition of Greece during the life of Plato

The life of Plato extends from 427-347 B.C. He was born in the fourth year of the Peloponnesian war, and he died at the age of 80, about the time when Olynthus was taken by the Macedonian Philip. The last years of his life thus witnessed a melancholy breach in the integrity of the Hellenic world, and even exhibited data from which a far-sighted Hellenic politician might have anticipated something like the coming subjugation, realised afterwards by the victory of Philip at Chseroneia. But during the first half of Plato's life, no such anticipations seemed even within the limits of possibility. The forces of Hellas, though discordant among themselves, were superabundant as defensive efficacy, and were disposed rather to aggression against foreign enemies, especially against a country then little formidable as Macedonia. It was under this contemplation of Hellas self-acting and self-sufficing—an aggregate of cities, each a political unit, yet held together by strong ties of race, language, religion, and common feelings of various kinds—that the mind of Plato was both formed and matured.

In appreciating, as far as our scanty evidence allows, the circumstances which determined his intellectual and speculative character, I shall be compelled to touch briefly upon the various philosophical theories which were propounded anterior to Sokrates-as well as to repeat some matters already brought to view in the sixteenth, sixty-seventh, and sixty-eighth chapters of my History of Greece.