It should never be forgotten for a single moment that the central and essential work of the Magician is the attainment of the Knowledge and Conversation of the Holy Guardian Angel. Once he has achieved this he must of course be left entirely in the hands of that Angel, who can be invariably and inevitably relied upon to lead him to the further great step—crossing of the Abyss and the attainment of the grade of Master of the Temple.
In most of his writings, Crowley described the Holy Guardian Angel as one's "Silent Self", at times equitable with one's deepest unconscious. In later writings, he insisted that the HGA is an entirely separate and objective being. Whichever position is taken, the object remains the same—to gain an intimate spiritual connection so that one's True Will can become fully known and manifested. When using the Tree of Life as a guide, this event occurs in the Sphere of Tiphareth.
Crowley wrote Liber Samekh as an example of a ritual designed specifically for attaining the Knowledge and Conversation with one’s HGA. In his notes to this ritual, Crowley sums up the key to success: “INVOKE OFTEN.” Another detailed description of the general operation is given in The Vision and the Voice, Aethyr 8
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