his semi-autobiographical novel, Strange Life of Ivan Osokin. In this story, Ivan Osokin implores a magician to send him back to his childhood and give him the chance to live his life over again. The magician obliges, but warns Ivan that he will be unable to correct any of his mistakes. This turns out to be the case; although Ivan always knows in advance what the outcome of his actions will be, he is unable to keep himself from repeating those actions. Having re-lived his life up to the point of his conversation with the magician, Ivan asks in despair whether there is any way of changing the past. The magician answers that he must first change himself; if he works on improving his character, he may have a chance of making better decisions next time around. The earliest version of the novel, however, did not include the magician, and ended on "a totally pessimistic note". The revolution in Ouspensky's thoughts on recurrence – the idea that change is possible – took place after he became a disciple of the mystic George Gurdjieff, who taught that a person could achieve a higher state of consciousness through a system of strict self-discipline. When Ouspensky asked about eternal recurrence, Gurdjieff told him: Ouspensky incorporated this idea into his later writings. In A New Model of the Universe, he argued against Nietzsche's proof of the mathematical necessity of eternal repetition, claiming that a large enough quantity of matter would be capable of an infinite number of possible combinations. According to Ouspensky, everyone is reborn again into the same life at the moment of their death, and many people will indeed continue to live the exact same lives for eternity, but it is also possible to break the cycle and enter into a new plane of existence. Science and mathematics The Poincaré recurrence theorem states that certain dynamical systems, such as particles of gas in a sealed container, will return infinitely often to a state arbitrarily close to their original state. The theorem, first advanced by Henri Poincaré in 1890, remains influential, and is today the basis of ergodic theory. Attempts have been made to prove or disprove the possibility of Poincaré recurrence in a system the size of a galaxy or a universe. See also Notes References Further reading External links Causality Religious cosmologies Philosophy of religion Philosophy of time Periodic phenomena