Abstract: John Harris' theory of “Enhancing Evolution” underlines that human enhancements not only make better people， but also play a profound role in human evolution. Contemporary human enhancements under advanced technologies can directly edit and engineer human bodies， which greatly shorten the process of human evolution， and replace “natural selection” with “deliberate selection” and Darwinian evolution with “enhancement evolution”. Thus， human enhancements can be seen as “absolute good” or “positive moral duty”. However， Harris' critics think that Harris' definition of “enhancement” is too wide to figure out and “duty” is not clearly defined as well. Accordingly， they deny Harris' arguments and state that enhancements are no more than “prima facie duties”. Finally， the ethics of human enhancements calls for a responsible enterprise， i.e.， only human enhancements as a responsible “enterprise” can be recognized as a moral duty which we should both develop and adopt.

Key words: John Harris, human enhancement, moral duty, evolution, gene editing