Editing Ordo Templi Orientis (section)

===Under Reuss' leadership===
{{anchor|M∴M∴M∴|MMM|M.M.M.|Mysteria_Mystica_Maxima}}
Reuss met Aleister Crowley and in 1910 admitted him to the first three degrees of O.T.O. Two years later, Crowley was placed in charge of Great Britain and Ireland, and was advanced to the X° (tenth degree). The appointment included the opening of the British section of O.T.O., which was called the ''Mysteria Mystica Maxima'' or the M∴M∴M∴.<ref name="king2" /> Crowley then went to Berlin to obtain instructional manuscripts and the title of ''Supreme and Holy King of Ireland, [[Iona]] and all the Britains within the Sanctuary of the Gnosis''.<ref name="king2" /> Within the year, Crowley had written the Manifesto of the M∴M∴M∴ which described its basic ten-degree system with Kellner's three degree ''Academia Masonica'' forming the seventh, eighth and ninth degrees.

In 1913, Crowley composed the Gnostic Mass while in Moscow, which he described as being the Order's "central ceremony of its public and private celebration".{{sfnp|Crowley|1979|loc=ch. 73}} In 1914, soon after World War I broke out, he moved to the United States. It was around this time that Crowley decided to integrate Thelema into the O.T.O. system, and in 1915 prepared revised rituals for use in the M∴M∴M∴.

In 1917, Reuss wrote a ''Synopsis of Degrees'' of O.T.O. in which the third degree was listed as "Craft of Masonry" and listed the initiations involved as "[[Freemasonry#Degrees|Entered Apprentice]], [[Freemasonry#Degrees|Fellow Craft]], Master Mason" and elaborated on this with "Full instruction in Craft Masonry, including the Catechism of the first three degrees, and an explanation of all the various Masonic systems". The same document shows that the fourth degree of O.T.O. is also known as the [[York Rite#Holy Royal Arch|Holy Royal Arch]] of Enoch. It was summarized by Reuss as the Degree of "Scotch Masonry", equivalent to "Scotch Mason, Knight of St. Andrew, Royal Arch", and he described it as "Full instruction in the Scottish degrees of Ancient and Accepted Masonry".<ref name="king" />

In 1919, Crowley attempted to work this Masonic-based O.T.O. in Detroit, Michigan. The result was that he was rebuffed by the Council of the Scottish Rite on the basis that O.T.O. rituals were too similar to orthodox Masonry.<ref>Kaczynski, Richard. ''Panic in Detroit: The Magician and the Motor City'' (2006)</ref> He described this in a 1930 letter to [[Arnold Krumm-Heller]]:

{{blockquote|However, when it came to the considerations of the practical details of the rituals to be worked, the general Council of the Scottish Rite could not see its way to tolerate them, on the ground that the symbolism in some places touched too nearly that of the orthodox Masonry of the Lodges.<ref>Starr, Martin. ''[http://freemasonry.bcy.ca/aqc/crowley.html Aleister Crowley: Freemason!]''. Retrieved June 17, 2006.</ref>}}

Crowley subsequently rewrote the initiation rituals of the first three degrees, and in doing so removed most of those rituals' ties to Masonry. He did not, however, rewrite the fourth degree ritual, which remains in its form and structure related to the various Royal Arch rituals of Masonry.