  Six of the medical manuscripts are concerned with nurturing life in various ways. “Harmonizing Yin and Yang” (He yin yang 合陰陽) and “Discussion of the Realized Way of All Under Heaven” (Tianxia zhi dao tan 天下至道談) are concerned with sexual cultivation. They refer to the movements and postures of animals as whole-body metaphors for sexual techniques. An example is the description of ten postures in “Harmonizing Yin and Yang”: