Both Stephen R. Donaldson and P. D. Ouspensky are known for esotericism?
Stephen R. Donaldson:  His work is characterized by psychological complexity, conceptual abstractness, moral bleakness, and the use of an arcane vocabulary, and has attracted critical praise for its "imagination, vivid characterizations, and fast pace". P. D. Ouspensky: Pyotr Demianovich Ouspenskii (known in English as Peter D. Ouspensky, Пётр Демья́нович Успе́нский; 5 March 1878 – 2 October 1947), was a Russian mathematician and esotericist known for his expositions of the early work of the Greek-Armenian teacher of esoteric doctrine George Gurdjieff, whom he met in Moscow in 1915.
i don't know