Practice of conservation biology that does not actively and continuously question the values that shape it is self-defeating: Conservation biology is inescapably normative. Advocacy for the preservation of biodiversity is part of the scientific practice of conservation biology. If the editorial policy of or the publications in Conservation Biology direct the discipline toward an ''objective, value-free'' approach, then they do not educate and transform society but rather narrow the focus to the ''object of knowledge'' (be this species, gene pools, landscapes, or ecosystems). To pretend that the acquisition of ''positive knowledge'' alone will avert mass extinctions is misguided. Conservation biologists should reflect on the constitutive values (especially contextual, but also methodological and bias) underlying their research programs and policy recommendations. Such reflection is itself and inherent element of scientific objectivity and takes into account the social nature of scientific knowledge. Without openly acknowledging such a perspective, conservation biology could become merely a subdiscipline of biology, intellectually and functionally sterile and incapable of averting an anthropogenic mass extinction.