Teaching and public life
Turnbull’s birth, education and family history are not securely established in the sources available here. His published work gives a clearer picture of his career. A revised edition of The Divine Language of Celestial Correspondences was in circulation in 1905, combining spiritual interpretations of the zodiac with instructions and tables for constructing horoscopes. He also wrote about Giordano Bruno and edited older astrological material for students, including The Astrologer’s Guide.
In 1923 he was writing from Pasadena, California. The prologue to The Solar Logos is signed there on 24 May, and the title page names the local Gnostic Press. In his introduction he explained that the book developed from lectures, written up at the request of students in different countries. The published studies carried his teaching beyond the lecture room.
In 1927 Turnbull became one of the founding governors of the Aquarian Foundation, the religious organisation established in British Columbia by Edward Arthur Wilson, known as Brother XII. Historian John Oliphant identifies him as an astrologer from Santa Cruz and the author of The Solar Logos. A photograph records him with the other governors at their meeting on 25 July. His appointment connected his teaching to a new religious community on Vancouver Island.
The planets and the spiritual life
The Solar Logos presents the Logos, or divine Word, as the ordering power shared by the universe and the individual. Turnbull drew on Christian scripture, Gnostic imagery and other religious traditions to argue that apparently different paths could lead towards the same spiritual understanding. Writing after the First World War, he saw disillusionment with conventional theology as a reason to reinterpret religion rather than abandon it.
