Clear Body, Clear Mind is a book published in 1990 by the Church of Scientology's publishing house Bridge Publications. It is credited to L. Ron Hubbard who died four years earlier, and is largely a compilation of material he wrote in the 1960s. It is one of the canonical texts of Scientology and mainly deals with the Purification Rundown ("Purif"). This "detoxification" program, created by Hubbard, is believed by Scientologists to have unique medical and spiritual benefits, but has been criticized by medical professionals as "dangerous", "quackery," and "in some cases lethal".