Topic description:
I would like to highlight the elusive nature of the concept of "biodiversity" as it is commonly used by ecologists and conservationists. I will question the scientific nature of this concept. Indeed, biodiversity is apparently the only scientific concept based on a notion of diversity qua diversity. This point has been underestimated by philosophers, although "biodiversity" is at the core of many important ecological theories. I will first explore the metaphysical ground on which the property of "diversity" is based. I will continue by analyzing the different senses of the notion of diversity and argue that the concept of biodiversity per se is NOT scientific but aesthetic in nature. I will then argue that we should understand "biodiversity" as a family of limited concepts (or "surrogate" concepts, as Sahotra Sarkar calls them) of many different biodiversities. This plurality of concepts can be analyzed following three different traditions: - biodiversities as concepts which are socially constructed in a normative context - biodiversities as different « perspectives » (in Wimsatt’s sense) of a complex system - biodiversities as a symptom of the anarchic nature of scientific theories (in Feyerabend’s sense) This last interpretation has new implications in a conservationist perspective that I will briefly tackle.

Biographical note:
Julien Delord is currently lecturer (attaché temporaire d'enseignement et de recherche) at the Ecole Normale Supérieure in Paris. He graduated in 1998 from the leading engineering university for life sciences in Paris (INA PG) with a MSc in Ecology. He then studied the History and Philosophy of Science at the University of Paris-Sorbonne and completed a PhD in the History and Philosophy of Ecology entitled, "The Extinction of Species: Historical and Ethical Issues of an Ecological Concept." Since 2003 he has been lecturing at different French universities in the history of science and has participated in the organization of an international conference on Biodiversity at the UNESCO in 2005. From 2005 to 200t he was a Fellow at the KLI. His main research interest lies in the history and epistemology of ecology and in environmental ethics. In 2004, he was awarded the second prize for young researchers of the French Biodiversity Institute.