上游充通大兽 Plato's ideal state SHANGHAI JIAO TONG UNIVERSITY Two underlying principles of any society:mutual needs and differences in aptitude. Five main economic classes of any polis: producers,merchants,sailors/ship owners,retail traders,and wage earners. Four virtues of a "just city":wisdom,courage, moderation,and justice. With all of these principles,classes,and virtues,it was believed that a "just city"(polis)would exist.Plato’s ideal state Two underlying principles of any society: mutual needs and differences in aptitude. Five main economic classes of any polis: producers, merchants, sailors/ship owners, retail traders, and wage earners. Four virtues of a "just city": wisdom, courage, moderation, and justice. With all of these principles, classes, and virtues, it was believed that a "just city" (polis) would exist