Dianetics comes from the Greek dia meaning “through” and nous, “mind or soul.” Dianetics is further defined as “what the soul is doing to the body.”
Dianetics uncovers the source of unreasonable fears, upsets and insecurities, unexplainable pains, sensations and emotions (psychosomatic illnesses) and sets forth effective handlings for these conditions.
For more information see Dianetics: An Introduction.
Scientology is defined as “the study and handling of the spirit in relationship to itself, to universes and to other life.” Through the practice of Scientology one can increase his spiritual awareness and ability and realize his own immortality. Dianetics is a forerunner and substudy of Scientology.
For more information see What Is Scientology?