Ahura Mazda

===Present-day Zoroastrianism===
In 1884, [[Martin Haug]] proposed a new interpretation of ''Yasna'' 30.3 that subsequently influenced Zoroastrian doctrine significantly. According to Haug's interpretation, the "twin spirits" of 30.3 were Angra Mainyu and Spenta Mainyu, the former being literally the "Destructive Spirit"<ref group="n">For an explanation of the approximation of ''mainyu'' as "spirit", see [[Angra Mainyu]].</ref> and the latter being the "Bounteous Spirit" (of Ahura Mazda). Further, in Haug's scheme, Angra Mainyu was now not Ahura Mazda's binary opposite, but—like Spenta Mainyu—an [[Emanationism|emanation]] of Him. Haug also interpreted the concept of a free will of ''Yasna'' 45.9 as an accommodation to explain where Angra Mainyu came from since Ahura Mazda created only good. The free will made it possible for Angra Mainyu to ''choose'' to be evil. Although these latter conclusions were not substantiated by Zoroastrian tradition,{{sfn|Boyce|1983|p=685}} at the time, Haug's interpretation was gratefully accepted by the [[Parsis]] of Bombay since it provided a defense against Christian missionary rhetoric,<ref group="n">Most prominent of these voices was that of the Scottish Presbyterian minister [[John Wilson (scholar)|John Wilson]], whose church was next door to the M. F. Cama Athornan Institute, the premier school for Zoroastrian priests. That the opinions of the Zoroastrian priesthood were barely represented in the debates that ensued was to some extent since the priesthood spoke Gujarati and not English, but also because they were (at the time) poorly equipped to debate with a classically trained theologian on his footing. Wilson had even taught himself Avestan.</ref> particularly the attacks on the Zoroastrian idea of an uncreated Evil that was as uncreated as God was. Following Haug, the Bombay Parsis began to defend themselves in the English-language press. The argument was that Angra Mainyu was not Mazda's binary opposite but his subordinate, who—as in Zurvanism also—''chose'' to be evil. Consequently, Haug's theories were disseminated as a Parsi interpretation in the West, where they appeared to be corroborating Haug. Reinforcing themselves, Haug's ideas came to be iterated so often that they are today almost universally accepted as doctrine.{{sfn|Boyce|1983|p=686}}{{sfn|Maneck|1997|pp=182ff}}<ref group="n">For a scholastic review of the theological developments in Indian Zoroastrianism, particularly concerning the devaluation of Angra Mainyu to a position where the (epitome of) pure evil became viewed as a creation of Mazda (and so compromised their figure of pure good), see {{harvnb|Maneck|1997}}</ref>