The Mind Benders was written by Cyril Vosper, a scientologist of 14 years who had become disillusioned, Published in 1971 (hardback, Neville Spearman, ISBN 0-85435-061-6) and reprinted in 1973 (softcover, Mayflower, ISBN 0-583-12249-3), it was the first book on Scientology to be written by an ex-member and the first critical book on Scientology to be published (narrowly beating Inside Scientology by Robert Kaufman). It describes the lower levels of Scientology and its philosophy in detail (it does not go into the Operating Thetan levels) and also includes the story of Vosper's expulsion from the Church.