Authenticity is outlined not as just a value we should strive toward, but instead synonymous with good health. He described how disclosing ones true thoughts and feelings, or phenomenal experience, is how one gets to know ones true self, which is crucial to mental and physical well-being. This book was written in the 1960's, when psychotherapy was sharply on the rise, and theorizes this is because man has become increasingly alienated from his own self.
He described the placebo affect not as just for affecting naive, impressionable or 'not really ill' people, but instead as faith-based healing, which is needed to have effective treatment of any kind.
He goes into some detail, a few chapters, how mental and medical professionals would be more effective in their work if they were authentic to themselves, thus allowing their patients to do the same. Physiological data is as important as psychological data too, he says, and should be recorded on medical sheets just like heart rate and other standard check-up criteria.
I like the focus on the individual and authenticity is how to avoid illness. Striving to fit social norms and expectations creates a self-alienated man, who doesn't even know his own self, emotions, and is frequently the victim of anxiety, stress, boredom and depression. And that being true to ones one self, by acting in accordance to your own desires and emotions, will foster an environment resistant to germs and disease.
His social theories I really enjoyed since they appeal to my rebellious and independent nature. He says that striving for "normality" or to fit a social role is detrimental to self and striving to fit perceived standards will not allow a person to maximize their potential for self-actualization.