Biodiversity is a term easily applied in different and differing contexts. At first glance it seems to be a biological concept, defined and used in the realm of biological theory, serving for the description of particular aspects of the human and non-human environment. In this sense biodiversity even found its way into the texts of international conventions: “Biological diversity means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic systems and the ecological complexes (...) of which they are part; this includes diversity within species, between species and of ecosystem.” [Harper and Hawksworth (1995)] But despite this clear and distinct definition, the intension of the term BD seems to be ambiguous. This is true for the single aspects of the definition itself, for example, the discussion over “what is a species?” took place in biology during the last 200 years and it is far from being finished [Claridge et al. (1997) Species]. This discussion asks not only for the “correct” biological definition of the term, but at the same time the methodological status of this term is in question. The result of this situation can be seen in the existence of at least 10–20 different definitions, considering biological as well as methodological aspects [Bachmann (1998) Theor Biosci 117:213–230]. Setting aside the fundamental scientific problems even the application of the term, its parametrisation and finally its relevance for biological theory-building is subject matter of controversies. The same is true for further particles of the definition, e.g. the term “ecosystem”, “complexity”, “gen”, “organisms”, etc. The intensity of the debate contrasts in a peculiar way to the reaction of (non-evolutionary) biologists, insofar as the biological research seems to be untouched by the irritating results of the debate itself. Referring to this strange situation, the aim of our article is a reconsideration of the term “biodiversity”. From an epistemological point of view it can be shown that a definition of biodiversity is possible which does not refer to biological knowledge and know-how—at least in its very first steps. Biodiversity then turns out to be a metaphor for specific aspects of societal organisation, the structuration and reproduction of nature-society relations within societies, and not for biological facts at all. (shrink)

I discuss various reactions to my article “Again, what the philosophy of science is not” [Callebaut (Acta Biotheor 53:92–122 (2005a))], most of which concern the naturalism issue, the place of the philosophy of biology within philosophy of science and philosophy at large, and the proper tasks of the philosophy of biology.