Past lives

In Dianetics, Hubbard proposed that the cause of "aberrations" in a human mind was an accumulation of pain and unconscious memories of traumatic incidents, some of which predated the life of the human. He extended this view further in Scientology, declaring that thetans have existed for tens of trillions of years (several orders of magnitude greater than what mainstream science generally estimates the age of the universe to be). During that time, Hubbard explains, they have been exposed to a vast number of traumatic incidents, and have made a great many decisions that influence their present state. Hubbard's 1958 book Have You Lived Before This Life contains descriptions of past lives given by individual Scientologists during auditing sessions. According to an early lecture of Hubbard's, it is, as a practical matter, both impossible and undesirable to recall each and every such event from such vast stretches of time.[23] As a result, Hubbard's three decade development of Scientology focused on streamlining the process to address only key factors. Hubbard stated that Scientology materials as described in books, tapes, and research notes include a record of everything that was found in the course of his research.[citation needed]

Source: http://en.wikipedia.org/wiki/Scientology