This chapter concerns the ethics of enhancing human abilities and characteristics beyond normality. It begins by exploring what enhancing in this context means and how it might be distinguished from other commonly accepted enhancement practices, such as training or education. It then moves to explore some key arguments that oppose such practices. The first (Kass LR (2003) Ageless bodies, happy souls: biotechnology and the pursuit of perfection. New Atlantis Spring:9–28. Available online http://www.thenewatlantis.com/publications/ageless-bodies-happy-souls. Accessed 29 Mar 2011) on the grounds that such methods threaten our agency as human beings; we as human beings would ultimately be less responsible for our achievements. The second (Sandel MJ (2007) The case against perfection. The Belknapp Press of Harvard University Press, Cambridge, MA/London) argues against certain practices as reflecting a problematic attempt to master our human nature. After exploring the limitations of such arguments, liberal arguments that support such enhancement practices are addressed. Such arguments often stipulate the need to ensure safety and the fair distribution of enhancement technologies. Further arguments support such enhancements as reflective of rather than threatening our human nature. On such a view, what is important about us as human beings is our striving to be better and making choices to support this.