A fellow of the Royal Asiatic Society and leading authority on G. I. Gurdjieff, Moore became active in practical and thematic Gurdjieff studies in 1956, after coming into contact with Kenneth Walker and later with Henriette H. Lannes ("Madame Lannes") as his Gurdjieffian teacher and mentor (in the period October 1957 — December 1978). His first major study, Gurdjieff and Mansfield (1980), examines the lives and brief intersection of Gurdjieff and the noted short story writer Katherine Mansfield. Moore lays to rest the persistent misconception that Gurdjieff was somehow responsible when Mansfield, who arrived at Gurdjieff's institute in France suffering from terminal tuberculosis, died within a few months, while still his guest.
From 1981 to 1994, Moore was responsible for gathering and leading new students in the Gurdjieff Society in London. He contributed to research for the 363 page "Gurdjieff: an Annotated Bibliography" (1985) compiled by J. Walter Driscoll and the Gurdjieff Foundation of California. During this period he was also a pupil of Henri Tracol and Maurice Desselle.
Although Moore is "biased" as a confessed admirer of Gurdjieff and for some time a member of a Gurdjieff group, his biography, Gurdjieff: The Anatomy of a Myth (1991), is allegedly distanced from its subject by Moore's sense of irony. It was republished in 1999 with a revised introduction, under the title Gurdjieff: A biography.
In 1994 Moore published "Moveable Feasts: the Gurdjieff Work" in an academic journal, challenging certain significant innovations in Gurdjieffian theory and practice introduced worldwide by Jeanne de Salzmann, the Work's de facto leader. (See external links for text of this article.) This meant Moore was obliged to leave the Gurdjieff Society, and he tried to work independently.
In a privately published memoir, Gurdjieffian Confessions (2005), Moore briefly sketches his personal life and provides candid and vivid glimpses of his 38 years as a member of The Gurdjieff Society in London, between 1956 to 1994.