Ruby,
you need to clarify what you mean by "observation / contemplation"
mmmm, I think what I really mean is "non-revelation dependant", "non-dependant on a mystical connection with the supernaural", "non-dependant on enlightenment from a supernatural entity". Strictly speaking, this doesn't necessarily narrows it down to empiricism, although would be a substantial part of it. There are other ways to knowledge beyond sensory experience, such as imagination, mathematical logic, methaphysics ... In a sense, Descartes would say that our senses may trick and deceive us, so they're not entirely reliable. Let's say that "revelation" is prone to deception - voluntary or involuntary.
So, a religion which, at its core, doesn't need to resort to the supernatural in order to satisfy the human drive for "spirituality" or explain the world around us. To be sure, those movements do exist, but, to my knowledge, they are all post-rationalism. I'm interested in realizing if there are any such BEFORE rationalism era.
Eden