Rational reflection and objective evaluation are warranted for medical advances and their effects on human health. The finiteness and unpredictability of science determines its limitation. Medical knowledge on human body and diseases are still restricted, thus, the concept that "medical science is omnipotence" should not be followed. Medical science could not be overvalued, and requirements for medical practitioners should not overpass the limitation of science. There is no elixir in our medicine, so it is impossible that medical science totally reassures disease diagnosis as well as treatment. In summary, medical science for mortals is a mortal herself.