According to Wikipedia:
> Aztec priests had a panentheistic view of religion but the popular Aztec religion maintained polytheism. Priests saw the different gods as aspects of the singular and transcendent unity of Teotl but the masses were allowed to practice polytheism without understanding the true, unified nature of their Aztec gods.
This is not an exception in the evolution of polytheistic cultures. Judaism was originally polytheistic as well but evolved into monotheism, though many OT texts still echo polytheism. Arguably, the only surviving religion that regressed from monism into esoteric polytheism is Christianity, through the concept of the trinity.