Sir: Professor Ernst says that the existence of Yin and Yang has never been demonstrated convincingly. As an acupuncturist, I must remark that this statement is typical of much scientific work that is done on alternative medicine. Chinese culture has evolved complex concepts which cannot be translated directly into modern scientific theory and which are then mistranslated. Yin and Yang are not entities as Professor Ernst implies; they are complementary attributes, such as "cooler" and "hotter". An authentic statement in Chinese medicine is that an elevated body temperature is more yang than a normal temperature, which is correspondingly more yin in relation to the higher temperature.
The problem is that scientists are not taking the trouble to learn the complexities of the alternative theoretical framework they are studying. Chinese civilisation is very evolved. Is it likely that it would employ fundamental concepts that have no basis in reality?