Dianetics: The Modern Science of Mental Health (May 1950): This is Ron's first major statement of the theory and practice of Dianetics, published on May 9, 1950. In it he isolates the dynamic principle of existence (Survive!) and his discovery of the reactive mind and its engrams. He lays out the reactive mind's anatomy and content, the mechanisms by which it can affect the individual negatively and then lays out the practice of how to relieve its effects and, ultimately, rid oneself of it through auditing. The book includes the first version of the Tone Scale, describes the State of Clear and lays out the conduct and disciplines of the auditor. The first part of the book postulates a goal for humankind, Survive! and its four division that he termed the Dynamics. The second part details the mind and its two divisions, the analytical mind and the reactive mind, targeting the latter as the single source of psychosomatic illness and aberration in the form of engrams. In Book Three, he describes therapeutic techniques to rid the reactive mind of engrams and goes into detail about the auditor and his role as the therapist and the auditor's code of conduct.