I take issue with the other reviewer who rated all NiHuaChing's books (and Master Ni) negatively. Let this person share his wondrous credentials. The person obviously has a personal grudge and I would be very careful and read at least one of NiHuaChing's books in order to properly JUDGE FOR YOURSELF. I met NiHuaChing several times in the late 70's, knew some of his students, and found Master Ni to be sincere in his desire to share knowledge which has been passed down from antiquity. His students learn everything from tai chi tailored to the seasons to herbology and Chinese medicine. In my opinion, Master Ni's books can be helful by themselves, or as supplements to your own studies and classes. He speaks plainly and never condescends. I have read several of his books and have found them to be quite steady and on the mark.