The life of Aristotle, so far as it illustrates this treatise, may be summarized in a few words. He was by birth a Greek, but a native of the small city of Stageira which stood upon the fringe of the Greek world; he was therefore well fitted by his origin to be an impartial, yet sympathetic critic, of the more famous city-states of Greece. In his youth he studied philosophy at Athens under Plato, thus coming at the most impressionable period of his life into close relations with the profoundest thinker whom Greece had yet produced. After the death of Plato(347), he quitted Athens to spend some years in the service of the new race of monarchs whose mission it was to diffuse Greek culture through the East and at the same time to complete the destruction of all that was most valuable and characteristic in the political life of Greece. At the court of Hermias, the obscure tyrant of the obscure city of Atarneus, Aristotle had the opportunity of observing the once great, but then decadent, despotism of Persia, to which he makes some references in the Politics. In 343 or 342 he migrated to Macedonia, joined the court of Philip, and acted for three years or so as tutor to the youthful Alexander. The results of his experience in Macedonia, and the drift of the political teaching which he gave to his pupil may perhaps be inferred from the comments which, in several passages of the Politics, he passes on monarchies and tyrannies.