This is part 6 of 10 in a series of lectures on Qin Bowei’s 56 methods. It covers the topics of Deficiency (part 2) and Cold (part 1). We discuss the source, causes, mechanism, locations, disease manifestations, and presenting symptoms, understanding the broad picture of Cold. Then we learn the associated treatment principles of Deficiency and Cold. We cover key diagnostic criteria for each principle, the associated flagship formula for each, how to modify it, how it relates to classical Chinese medicine, and finally numerous case studies to demonstrate how they are used in the real life clinic.