You believe/know all that, but still remain an atheist? It depends on the conversation. I could be backed into agnosticism with the right arguments, but not in any practical sense. That position would reach no further than that specific conversation. As Kant remarked, "Experience without theory is blind, but theory without experience is mere intellectual play." Blake is saying this reductionist focus on the material "blinds the mocking eye". The rationalists ( I may not be using this term properly) can only see one facet of the gem. I think physicalists might be what you are looking for; rationalists would be Descartes, Spinoza, and Leibniz, who could be accused of having seen possibly nonexistent facets.