The book expounds the ideas of Russian mystic G.I. Gurdjieff. P.D. ouspensky, himself a mathematician philosopher, met Gurdjieff in 1914 and during his discipleship of 8 years learned the secrets of cosmology as put by Gurdjieff as well as the place of human beings in the pyramid of our cosmos. As he puts it "Man is not free. He is in prison and fulfills the need of cosmos in its food-chain. He is doomed to be remain so , if he does not realize the horror of his position and bound to move in the circle of involution & evolution." This can be achieved only through a conscious "Work" i.e. SADHANA on oneself.
This book also narrates many interesting incidents of his association with Gurdjieff and the most authentic description of his whole ideas. A must read for every inquiring mind.