P. D. Ouspensky, 1878-1947, is best known as the author of In Search of the Miraculous, which is the principal systematic rendition of Gurdjieff's 4th Way teaching.
Prior to meeting Gurdjieff in Moscow in 1915, Ouspensky had worked as a journalist and published metaphysical and philosophical works. Among them Tertium Organum and a New Model of the Universe. Concerning the latter, Gurdjieff is believed to have said 'If you did understand all of what you are writing about, it is I who would beg to be your student.' Ouspensky recognized in the teachings of Gurdjieff something on a qualitatively different level than all that he previously had encountered on his relatively extensive travels and in his broad social network. Ouspensky followed Gurdjieff to the Caucasus, fleeing from the Russian revolution. In Essentuki, Ouspensky began distancing himself from Gurdjieff, not because he would disagree with the teaching but apparently because he found Gurdjieff as a person to be too extreme. The cooperation between Ouspensky and Gurdjieff did continue however during their stop in Constantinople in 1920 and on and off thereafter. While Gurdjieff set up his institute in Fontainebleau, Ouspensky started his own 4th Way school in London.
Ouspensky knew Boris Mouravieff and was clearly aware of the latter's information on the Adamic and Preadamic races, as evidenced in Ouspensky's collection of short stories 'Talks with the Devil.' This would indicate that the material was also known to Gurdjieff, although he and Ouspensky chose not to emphasize it.
We could say that where Gurdjieff was man 1, with a moving center emphasis, Ouspensky was man 3, with his center of gravity in the intellect. This accounts for a difference in their respective styles and methods of teaching. We recognize that the distinction of man 1, 2 and 3 becomes less important as the Work progresses, yet the original emphasis does not entirely disappear. Of the two, Gurdjieff was clearly the source of the teaching and the more powerful personality and an uncontested master. Yet Ouspensky's contribution remains significant as the recorder and scribe of much material. He brought many key people to the Work and without his contribution Gurdjieff's impulse to humanity would not have reached as far as it has.
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