Christian Science and Scientology both claim to be religions but are rejected by most mainstream faiths and scientists. Christian Science was founded by Mary Baker Eddy and teaches that disease is an illusion that can be cured through spiritual means alone. Scientology was created by science fiction author L. Ron Hubbard and is based on concepts like past lives, immortal spirits called Thetans, and using an e-meter device during auditing sessions to eliminate engrams from past traumatic experiences. Neither faith is grounded in science and both have faced criticism for discouraging medical treatment and being more akin to pseudoscience than religion.