Abstract: The ethical discussion on human enhancement technology faces difficult problems in defining the concept of “enhancement”. Different understandings of the concept of “enhancement” directly affect people's attitudes towards this technology， and form two groups: bioconservatism and transhumanism. Both sides give their own moral justifications based on the views of mainstream ethics such as deontology and consequentialism. A critical examination of the two main groups reveals that there is a fundamental divergence between bioconservatism and transhumanism， not only in how the concept of “enhancement” itself is defined， but also in the philosophical paradigms and research approaches they follow in defining it， i.e. different answers to the questions about the relationship between human beings and technology， technology and ethics. By comparing the different theoretical strategies adopted by the two in dealing with the crisis of transhumanism revolution， we can see the theoretical advantages of transhumanism that adhere to the “internalism” approach at the ontological and epistemological levels.

Key words: human enhancement technology; bioconservatism; transhumanism; externalism; internalism