I would be curious to know more about how they describe the "seat of knowledge" in the Iyengar tradition. As I understand, in all yoga traditions God is understood as occurring within. We do these practices in order to align the higher, "god self" with the lower, perhaps "material self". How is it possible to be an atheist if "God" is understood as occurring within ourself? I don't actually use the word "God" much, but "divine", since "God" is a barrier for some. I don't see how the idea of "God", or an external "creator" would be reinforced as something external in any conceivable translation of the sutras. I don't have mine in front of me but I'll take a peek later.