Abstract: Cultural diversity,which contains value diversity and diversity of belief,goes along with the history of human civilization and cannot lead to cultural homogenization because of globalization.Social order is laid on the foundation of moral consensus,democracy,and rule of law in the context of cultural diversity.Deconstructive postmodernism becomes available after the collapse of arbitrary rationalism;however,the moral relativism and nihilism implied in it are harmful.Eurocentrism goes bankrupt with the collapse of arbitrary rationalism.To maintain world peace and sustainable eco-civilization,people from different cultures should make dialogues and reach an agreement and realize fusion of horizons,following the fair rule of discourse ethic and the motivation of mutual learning.

Key words: polyphyletism, postmodernism, discourse ethic