In all of its eccentricity, Yeatss book, I insist in this study, is not finally the expression of an occult doctrine. Nor is it simply the setting  forth of a system designed to deliver Yeatss poems to a reader. Too often the presumption that it is one or both of these things has put off critics and readers. The occult in it is subordinate to the books literary purposes, one of which is to dramatise the fate of the poetic way of thing as Yeats saw it in his age. On this subject it has a great deal to say to us today. […] (pp.3-4.)
The 1925 Vision, published privately by Yeats, was the outgrowth of several years of Mrs. Yeatss automatic speech and writing. Like her husband, Mrs. Yeats had occultist interests dating from before they met. Early in their marriage, worried about her husbands state of mind, she faked automatic writing to distract him, only to learn that she was indeed a medium of some sort. The 1925 edition of A Vision , hiding her mediumship behind an elaborate fiction, is supposedly a distillation of what Yeats gleaned from her automatic writing and speech. At  first glance, A Vision reports a quasi-astrological occult system of thought that purports to classify types of human character according to twenty-eight categories based on the phases of the moon, to offer a theory of reincarnation, and, further, to order all of Western history according to lunar cyclical symbolism.
But Yeats was not at all satisfied with the first published version and worked on an elaborate revision for more than a decade, producing the very different second version in 1937. By this time, Yeatss understanding of his wifes communications was more sophisticated, in part because he had read more philosophy. Also, and perhaps more important, he had now the time to query his own experience with the communications and to develop an attitude toward them. In the new version he raised questions about his own belief in what he called the system, and that led in turn to the question of its purpose and the larger issues of belief that were preoccupying writers at the time. Yeatss attention to this issue and other matters in the new and more elaborate frame he caused to enclose his account of the system made the 1937 version virtually a new book.
The new frame Yeats constructed provided an extremely dense enviwnment for the abstract presentations inside it. A Vision was originally dedicated to Vestigia, the code name used in the Order of the Golden Dawn by Moina Bergson Mathers, sister of the philosopher and wife of the occultist MacGregor Mathers. In 1937 this dedication disappears, and the text begins with a group of three meditations entitled A Packet for Ezra Pound. There is included a section that describes the the experience with Mrs. Yeats, revealing the supposedly true source of the work.
Oddly enough, the second part of the book nevertheless presents a heavily revised and extended fictive explanation of the sources. The story told turns out to be a comic farce, in which Yeats revives certain characters from his earlier works and creates new ones. Thus, the introductory matter of A Packet for Ezra Pound presents one explanation of the systems genesis, allegedly true; and the second section of the book presents another, clearly fictive and so declared, in which Yeats himself is actually alluded to as one of the characters. For many people the true account is as fantastic as the fictive one. (pp.6-7.)
[Adams provides a composite diagram, with the introductory note:] We may now turn to the figur of the gyres […] The two gyres are also a wheel around which we can place the twenty-eight lunar phasis of Giraldus mathetic figure representing both human types and the passage through life. Although Yeats does not employ the gyres and the wheel in a diagram quite like the one in figure 4 [p.75], I believe that it is helpful to a better understanding of the ones he does provide. I superimpose the gyres on the wheel, provide the twenty-eight lunars phases, identify them according to Yeatss schema, and set the Faculties in motion around the wheel. (p.74.)
The two interlocking gyres represented by unbroken lines show us a person of Phase 17, the phase to which Yeats assigned himself in real life, though this is not mentioned in A Vision. His Will is therefore at that phase. His Mask is at Phase 3, directly opposite on the wheel.  His Creative Mind is at Phase 13, and his Body of Fate is at Phase 27. Now, if we set the Will moving counterclockwise around the wheel, when it reaches Phase 18, Mask will be at Phase 4, Creative Mind at 12, and Body of Fate at 26, producing the cones drawn in broken lines. If we further move Will around the wheel, we can produce all the possible relations among the Faculties. It will be seen that even at Phases 1 and 15, which Yeats calls supernatural phases, impossible to achieve in life, the two gyres disappear (as they do at Phases 8 and 22), but in none of these cases do Will and Mask or Creative Mind and Body of Fate meet. At 1 and 15, Will and Creative Mind are joined, as are Mask and Body of Fate. If life were possible at these moments, a perfect opposition or contrariety would be achieved. This is symbolized at Phase 15 by perfect physical beauty, more specifically by the art of the dance, and the pure image. At Phase 1, there is complete annihilation of body and image with only pure idea remaining. (p.74-75.)