  In summary, Sun Simiao, like Ge Hong and Tao Honjing combines explicit interests in Daoist philosophy, medicine, materia medica and alchemy. These physicians were informed by the yin-yang theory and cosmology of the Yi jing and the philosophical concepts of the Zhuangzi and Daode jing.  But, despite their strong philosophical interests, the major contributions of their writings lie in the areas of medicine, pharmacology and alchemy.