Claud Bernard thought the body's own equilibrium and internal environment were more important than microbes. Bernard had theories and guesses. Today we know this is false. Illness does not simply progress in a straight line. Literature is filled with stories of spontaneous remission of disease.
Some people get well without benefit of intervention.
Pain is not always a sign of disease. Sometimes it is telling us to not eat so much, stop smoking, or stop drinking too much. There is little question now that what goes into the mind has a tremendous effect on health. Can Fight For Your Life that emotions are involved even in the development of cancer. Yes, the mind and body are one.