The idea of Zoroastrian mysticism might at first glance seem a contradiction in terms. The Good Religion, after all, is čīmīg, “rational,” above all else: Zoroaster elegantly solved the most intractable mystery of all faiths, theodicy, by the revelation of cosmic dualism. The mere assertion that there are esoteric doctrines within Zoroastrianism has been criticized. This criticism springs in...