Perspectives in conservation can be based on a variety of value systems and normative postulates. Perspectives also vary between cultures. Such differences in what and how people value nature, underlie many disagreements and conflicts during the formulation and implementation of environmental management policies. Specifically, whether an action intended to promote conservation (e.g. killing cats to save birds threatened with extinction) is viewed as moral can vary among people who hold different value systems. Here, we present a conceptual framework that mathematically formalises the interplay of value systems. We argue that this framework provides a heuristic tool to clarify normative postulates in conservation approaches, and highlights how different value systems might rank various management options differently. We illustrate this by applying the framework to specific cases involving invasive alien species, rewilding, and trophy hunting; and comparing how management decisions would likely be viewed under different idealised value systems (ecocentric conservation, new conservation, and compassionate conservation). By making value systems and their consequences in practice explicit, the framework can facilitate debates on contested conservation issues, and, we hope, will ultimately provide insights into how conflicts in conservation can be reduced.