AbstractWhatever ethical stance one takes in the debate regarding the ethics of human enhancement, one or more reference points are required to assess its morality. Some have suggested looking at the bioethical notions of safety, justice, and/or autonomy to find such reference points. Others, arguing that those notions are limited with respect to assessing the morality of human enhancement, have turned to human nature, human authenticity, or human dignity as reference points, thereby introducing some perfectionist assumptions into the debate. In this article, we ask which perfectionist assumptions should be used in this debate. After a critique of views that are problematic, we take a positive approach, suggesting some perfectionist elements that can lend guidance to the practice of human enhancement, based on the work of Martha Nussbaum's Capability Approach. We suggest that the central capabilities can be used to define the human aspect of human enhancement and thereby allow a moral evaluation of enhancement interventions. These central capabilities can be maximized harmoniously to postulate what an ideal human would look like. Ultimately, the aim of this article is twofold. First, it seeks to make explicit the perfectionist assumptions found in the debate and eliminate those that are problematic. Second, the paper clarifies an element that is often neglected in the debate about human enhancement, the view of the ideal human towards which human enhancement should strive. Here, we suggest that some central capabilities that are essential for an ideal human being can be maximized harmoniously and can therefore serve as possible reference points to guide human enhancement.