  A particular problem raised by the application of yin-yang theory to medicine was the implications of yin-yang theories for accounts of gender (Furth 1986, Raphals 1998, Yates 2005), including the problem of the androgyny of what Charlotte Furth calls “the Yellow Emperor’s body.” Furth argues that the human body is understood as androgynous before the development of gynecology in the Song dynasty. These models of the body inform the early history of yin-yang theory, and the gender analogies that form part of that discourse. A central text to these analogies is the Huang Di neijing, which is striking for its overall androgyny. Overall, women are not specified as medically distinct from men, and where they do occur, discussions of sexual difference are usually linked to specific questions of fertility and reproduction (e.g., Huang Di neijing suwen 1.3.8 and 7.2.26).