This is an essay from my blog: http://selzlab.blogspot.com/2007/09/secula...

There is a common notion among bigoted religious folks that only religion can protect Western society from the creeping evils of cultural and moral relativism. This notion that secularism causes relativism is based on the misconception that if social norms and moral codes are man-made they must be arbitrary.This misconception leads down 3 paths: One path is the road towards moral naturalism, the notion that "natural = good," one sees moral naturalism very often, especially in New Age circles, but it was a very common attitude of Enlightenment thinkers ("natural law," etc.), including America's founding fathers. The second path leads towards cultural relativism, the notion that since social norms and moral codes are man-made and thus "arbitrary" then they are morally equal to each other. The Third path says that if man-made social norms and moral codes are "arbitrary" then we must look to a higher power in search of a divinely inspired moral code and social norms. All three of these paths are incorrect and misconceived.

Human societies can be placed on a continuum going from the "closed society" on one end and the "open society" on the other end. primitive tribalistic societies are "closed societies" par excellence, such societies do not recognize the distinction between laws of nature and social norms, both are considered the work of supernatural entities. Most pre-modern societies were also fairly closed (though not as closed and primitive tribalistic societies), with both the laws of nature and the societies social norms being the work of the god/gods or the society's official religion, but the social norms are backed with the legal powers of the state, the powers of which are legitimized by appeals to the divine right of kings or the noble blood of aristocrats. The "open society" is the total opposite, social norms are recognized as man-made but NOT arbitrary, and thus can be criticized and changed peacefully through democratic means if they don't work.

Classical Greece was the first civilized society to start to move towards the open society, with the Democracy of Athens being the epicenter of this movement. As commerce brought knowledge of other cultures to Greece the authority of the social norms started to break down, this period saw the birth of Western Philosophy as well as the misconception that man-made social norms must be arbitrary, and thus the three misconceived paths I mentioned earlier originated in Classical Greece. The notion that man-made social norms are arbitrary emerged as the closed society broke down. It was the Athenian thinkers of the Age of Pericles, The latter Sophists and Socrates being the most famous, that moved passed this impasse and showed that just because social norms are man made does not mean they are arbitrary, and thus lead the way to the open society. In fact, this philosophical discovery triggered the birth of an anti-slavery movement in Athens that came close to succeeding. Athens was the first truly open society, and the last (it's legacy being betrayed by Plato, the first Fascist and enemy #1 of the open society) until the American Revolution.