"Disbelief in the supernatural is as old as the hills. It is only through profound ignorance of the classical tradition that anyone ever believed that 18th-century Europeans were the first to battle the gods. We tend to see atheism as an idea that has only recently emerged in secular western societies. The rhetoric used to describe it is hyper-modern. In fact, early societies were far more capable than many since of containing atheism within the spectrum of what they considered normal. Rather than making judgments based on scientific reason, these early atheists were making what seem to be universal objections about the paradoxical nature of religion – the fact that it asks you to accept things that aren’t intuitively there in your world. The fact that this was happening thousands of years ago suggests that forms of disbelief can exist in all cultures, and probably always have" (ver também aqui e aqui)