The theoretical foundation of TCM is deeply rooted in Chinese culture, which, however, is not as homogeneous as has been generally portrayed. From the native's point of view (Lei, 1991), the official or great tradition is socially presented as Confucian in name, whereas the unofficial or the little tradition subtly represented in people's daily life is mostly Taoist in nature. As most indigenous healers would agree, it is the Taoist Weltanschauung (worldview) that provides the principal concepts for TCM.