The concept of biodiversity has entered the law. Article intends to make the conceptual suppositions and the ethical profile of the biodiversity concept explicit. Article takes “biodiversity” as a hybrid concept located at the intersection of biological science, environmental ethics, and international conservation policies. It proceeds with sections on genealogy and definitions of the concept. Further, a matrix-scheme is construed serving the purpose to make debates on biodiversity more specific and precise. Moreover, different approaches in environmental ethics are assessed trying (...) to substantiate the conservation of biodiversity in its entirety (“all”), but mostly fail in the attempt. A “strong” sustainability approach, however, can justify the protection of many and most components. Finally, the dialectics of biodiversity is outlined. On the one hand, a method is outlined how to proceed in order to reach resonable judgements about conservation and utilization of specific components of biodiversity while, on the other hand, the philosophical dimension is taken into account. This philosophical dimension is two-fold: a) epistemology of living beings and b) biophilic existentialism. Finally, some open questions with respect to implementation of “biodiversity” into law are asked. (shrink)