in every religious ceremony, when each of the Amesha Spenta is visibly represented by objects of which they are the guardians. In addition, the first seven days of the month of the Zoroastrian calendar are dedicated to the great heptad and to creation, acknowledging the preeminence of the Amesha Spenta and so ensuring the inculcation of their doctrine. Ethical and ontological dualism in the same entity "accounts for the difficulty which some aspects of the doctrine have presented for Western scholars". The reverence of the Amesha Spenta and the Yazatas has been frequently attacked by non-Zoroastrian sources for its polytheist nature, not only in modern times but also the Sassanid era. While the "worship of the elements" was a repeated accusation during the 4th and 5th centuries, ⁣ Christian missionaries (such as John Wilson) in 19th-century India specifically targeted the immanence of the Amesha Spenta as indicative of (in their view) a Zoroastrian polytheistic tradition worthy of attack. A frequent target for criticism was the Zoroastrian credo in which the adherent declares, "I profess to be a worshiper of Mazda, follower of the teachings of Zoroaster, ... one who praises and reveres the Amesha Spenta" (the Fravaraneh, Yasna 12.1). Some modern Zoroastrian theologians, especially those identifying with the Reformist school of thought, believe that ethereal spirit and physical manifestation are not separable in any sense and that a reverence of Ahura Mazda's creations is ultimately a worship of the Creator. In the second half of the 19th century, Martin Haug proposed that Zoroaster himself had viewed the Amesha Spenta as merely philosophical abstractions and that a personification of the heptad was really a later corruption. The Parsis of Bombay gratefully accepted Haug's premise as a defense against the Christian missionaries and subsequently disseminated the idea as a Parsi interpretation, which corroborated Haug's theory. The "continuing monotheism" principle eventually became so popular that it is now almost universally accepted as doctrine. Notes References Further reading Corbin, Henry (1977). Spiritual Body and Celestial Earth: From Mazdean Iran to Shi'ite Iran''. Princeton University Press. Angels Ancient Iranian deities Holy Spirit