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 part from a flawed perception of mysticism itself, which, as it will be argued, is not an independent entity, everywhere the same. Rather, each religion has a mysticism of its own, often irreconcilable in some of its features with the mainstream, and, in the case of Zoroastrianism, with some of the religion's plain logic. Also, the existence of mysticism within a religious tradition does not imply its centrality to that tradition. Mysticism exists in Christianity, but could scarcely be called essential to it, considering the claim, elaborated as the Christian church rose to universal prominence, to the radically overt and sufficient truth of the Gospel.