Abstract
This chapter outlines how biotechnology can be seen as a challenge to our notion of nature, and how the complexity of the concept of nature in itself is a challenge in the debate on enhancement of capacities in humans, animals and plants by means of biotechnology. It then explores how the same concept contributes to the ethical arguments both for and against enhancement of human capacities, focusing on two central aspects of the enhancement debate namely: (i) the debate that focuses on enhancement as an overreaching form of therapy; and (ii) the debate that focus on enhancement as the goal in itself. Finally, the chapter summarizes the contribution of the concept of nature in terms of the challenges that its inherent complexity poses to the ethical and philosophical debate on enhancement technologies, also briefly discussing how “nature” and “naturalness” can be said to have moral relevance in the enhancement debate.