“Solar and logical / decadent and symmetrical / angels are mathematical.” Lyrics from Coil’s song “Fire of the Mind” (2005) come to me while I look at Emma Kunz’s gorgeous large-scale drawings. Kunz was a Swiss healer who began making these works in 1938, when she was 46. She had no formal artistic training, and the 500 or so drawings she made were never exhibited during her lifetime. For her, they were tools crafted as part of broader therapeutic and divinatory practices. Today they appear like a crew of decontextualized mathematical angels, as intense as they are inscrutable. The exhibition “World Receivers” puts Kunz in the company of Hilma af Klint and Georgiana Houghton, two women who also developed abstract visual languages as part of their personal esoteric investigations—af Klint in Sweden in the first decades of the twentieth century, Houghton in England in the second half of the nineteenth. The three differ from one another in important respects, but there are intriguing commonalities, including the fact that all of them trouble the notion of autonomous authorship by posing that creating be understood as a matter of receiving. Describing her process, af Klint wrote: “The pictures were painted directly through me, …