Contemporarily, biodiversity loss is the prominent concern of the conservation movement. In reaction to the escalating depletion of biodiversity, governments and organizations are crafting policies and strategies with a central focus on biodiversity conservation. Assessing the extent of biodiversity loss and its relationship with human society necessitates reliable ecological metrics. However, the tools used to assess biodiversity encompass not only empirical dimensions but also normative values that shape conservation outcomes. This review examines the normative dialog implicit in our conceptualizations and (...) measurements of biodiversity through the chronological framework of four conservation focal areas: Red Listing, species richness, environmental indicators, and the integration of human values. This investigation underscores the imperative to more clearly articulate the values of the conservation movement, a task that is even more pressing with the emergence of novel biodiversity finance tools. (shrink)