„Qi Bo said: “This is the Dao of needling: to promote the patient’s essence and spirit. If the essence and spirit (jing and shen) are not enhanced, and the will and intent (zhi yi yuan zhi de zhi, yisi de yi) are not controlled, then illness cannot be cured.

“In the present era, people’s essence is ruined and their spirit is gone, the nutritive and the protective qi cannot circulate fully. And why is this? (Because) there is no limit to eating and drinking, and (people ) worry ceaselessly: (Thus) essential qi is ruined, nutritive qi leaks out and protective qi is lost, (and the gradual end) result is loss of spirit and failure of the disease to be cured.”
(Steven Clavey; Fluid Physiology and Pathology in Traditional Chinese Medicine, Chp. 5 Edema, pg. 140; Churchill Livingstone;  Su Wenn Chp. 14 §4)