In 1938, Hubbard discovered what he believed to be the common denominator of existence, which was: SURVIVE. In a philosophic work entitled "Excalibur," Hubbard wrote:

I suddenly realized that survival was the pin on which you could hang the rest of this with adequate and ample proof. It’s a very simple problem. Idiotically simple! That’s why it never got solved. Nobody has ever looked at anything being that simple to do that much. So what do we find as the simplicities of solution? The simplicities of solution lie in this: that life, all life, is trying to survive. And life is composed of two things: the material universe and an X-factor. And this X-factor is something that can evidently organize, and mobilize the material universe.
Hubbard served as a Navy Lieutenant in World War II, and the bloodshed and its effects on man's mind that he observed made him more determined than ever to discover the answers to the human mind. In 1945, he was hospitalized at Oak Knoll Naval Hospital in Oakland, California. While recovering, he took the opportunity to experiment with the idea that mental blocks can prevent medical treatments from being effective. He found this theory to work on numerous patients, and concluded:  "Thought is boss."

After the war, Hubbard continued to test his hypotheses on a broad sample of people from all over the United States. He is said to have helped over 400 hundred people become healthier with the procedures he had developed, including himself. These procedures came to be called "Dianetics."