 So defined, neither sagehood nor immortality can be attained through learning or effort. However, the doctrine of ziran does not necessarily entail a strong determinism or “fatalism” that dismisses all human effort. Immortality may be beyond reach, but as Ji Kang explains in his essay “On Nourishing Life” (Yangsheng lun), self-cultivation can enhance one’s physical and spiritual well-being substantially. Specifically, breathing exercises, special diets and the use of drugs can help maximize the limits of one’s natural endowment, and bring about rejuvenation and long life. Drug use, incidentally, was widespread among the literati in early medieval China. He Yan, for example, is known to have championed a certain drug for its ability to “lift one’s spirit,” and Ji Kang is also reputed to have been a connoisseur in this field. In any case, knowledge of Dao and practice in the art of nourishing life can make a significant difference, even though they may fall short in transforming the person into an “immortal.”