The idea that a culture can only be truly evaluated by its own standards and not by any common criteria. Thus, cultural relativism is a liberal and "liberalizing" concept in the social sciences, and is, of course, rejected by the old conservative line. What is interesting is that radicals also reject cultural relativism, at least to a degree, particularly its "radical" version. Radical cultural relativism holds that the beliefs, values, and modes and organization of behavior of one culture can never be objectively or validly judged superior to those of another culture. This is, of course, quite contrary to humanists and socialists of one kind or another (Marxian, Christian, etc.) who postulate a "human essence" that when violated by any social structure or cultural system results in injustice - an injustice that must be properly criticized.