According to the mystical point of view there is one chief root, which can be called a common cause, from which all diseases are derived, and that is disorder of rhythm. The upset of the nerves is stated by scientists to be the chief origin of all mental diseases, and their effect upon the body produces various diseases in the body. Religious people teach concentration and meditation, sitting in a prayerful attitude. The wisdom behind all this is to bring the activity of mind and body to a normal condition.