Well, we have to decide what is meant by an "atheist civilization."
I was using the definition of athiest civilization to mean the professed beliefs of the majority of the population within such a civilization. However, as Jar pointed out in chat, civilizations themselves, being largely political entities rather than individuals, can't be athiest, they can only be theocracies, have state sanctioned religions, or be secular. The term athiest civilization under this definition is a meaningless term. Upon reflection, I now agree the second definition is more appropriate.
Sometimes I think the USA is one too. If they would only admit it.
The USA is a secular nation as it is not a theocracy, nor does it have a state sanctioned religion.
Edited by anglagard, : mixing nation with civilization