In the present Western cultural and political context, the concept of nature plays a central role in the debate about new technologies. However, the concept of nature is complex and reflects more than one frame of reference stemming from a long historical tradition. ‘Nature’ is referred to: a) as the object (phenomenon) toward which the debate is directed, and b) as the normative frame of reference that either justifies or rejects the technological method in specific situations. This paper argues, that this double character of ‘nature’ is not particular for the debate on ethical concern for the non-human nature, rather it constitutes the complexity of the concept itself. This, in turn, leads to a more fundamental question, namely: What is ‘nature’?—Or rather: Is ‘nature’ to be defined?