Liber XV, The Gnostic Mass

Aleister Crowley wrote The Gnostic Mass — technically called Liber XV or "Book 15" — in 1913 while travelling in Moscow, Russia. The structure is similar to the Mass of the Eastern Orthodox Church and Roman Catholic Church, communicating the principles of Crowley's Thelema. It is the central rite of Ordo Templi Orientis and its ecclesiastical arm, Ecclesia Gnostica Catholica.

The ceremony calls for five officers: a Priest, a Priestess, a Deacon, and two acolytes, called Children (though current practice is that the part is usually performed by adults). The end of the ritual culminates in the consummation of the eucharist, consisting of a goblet of wine and a Cake of Light, after which the congregant proclaims “There is no part of me that is not of the gods!”

Crowley explains why he wrote the Gnostic Mass in his Confessions:

While dealing with this subject I may as well outline its scope completely. Human nature demands (in the case of most people) the satisfaction of the religious instinct, and, to very many, this may best be done by ceremonial means. I wished therefore to construct a ritual through which people might enter into ecstasy as they have always done under the influence of appropriate ritual. In recent years, there has been an increasing failure to attain this object, because the established cults shock their intellectual convictions and outrage their common sense. Thus their minds criticize their enthusiasm; they are unable to consummate the union of their individual souls with the universal soul as a bridegroom would be to consummate his marriage if his love were constantly reminded that its assumptions were intellectually absurd.

I resolved that my Ritual should celebrate the sublimity of the operation of universal forces without introducing disputable metaphysical theories. I would neither make nor imply any statement about nature which would not be endorsed by the most materialistic man of science. On the surface this may sound difficult; but in practice I found it perfectly simple to combine the most rigidly rational conceptions of phenomena with the most exalted and enthusiastic celebration of their sublimity.

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