The purpose of the Habitats directive, based explicitly on scientific knowl
edge, is to preserve biological diversity on a European scale through the c
onservation of natural habitats and wild fauna and flora. It differs from t
he standard nature protection policy approaches because of the principles w
hich it espouses: maintaining biodiversity and sustainable development. The
use of these notions is clearly not neutral nor without consequences. In e
xploring the content of the biodiversity concept, this text seeks to demons
trate how it redefined nature. An analysis of the text of the directive rev
eals its theoretically innovative aspects and the difficulties of applying
this new nature policy. While it is dear that there are real difficulties o
f interpretation which can apply to all the countries involved, the room to
manoeuvre and the risks of conflicts vary from country to country because
they depend on the particular political culture. Our hypothesis is that bio
diversity, as conceived in the directive and the action framework proposed,
involves many contradictions which account for the outbursts in political
and scientific circles which its application caused in France.