Hugh Schofield reports at BBC.com: “Actress, activist, feminist, mystic, Maud Gonne was also the muse and inspiration for the poet W B Yeats, who immortalised her in some of his most famous verses… This was the attempt in late 1893 to reincarnate her two-year-old son, through an act of sexual intercourse next to the dead infant’s coffin.” You can read the entire article here: http://www.bbc.com/news/magazine-31064648
Yeats was a member of the Hermetic Order of the Golden Dawn as were Gonne and Aleister Crowley, Crowley eventually leaving and creating the A.’.A.’., his own Order, influenced by the Golden Dawn. In Crowley’s novel “MoonChild” he described a method for incarnating an Elemental Spirit in human form by having woman inseminated and while immersed in influences suggestive of the nature of the particular sort of Spirit one was seeking. Notoriously, Crowley took a dim view of Jack Parsons and Marjorie Cameron reputedly attempting such work with L. Ron Hubbard acting as seer and scribe.
Thanks to Soror Hypatia for the tip!