Motivated by philosophical quandaries arising from environmental ethics and the moral philosophy of biodiversity, we convened a special issue of Biological Conservation entitled “Ethics and practice of biodiversity science: how hidden moral assumptions impact conservation research and policy,” inviting a range of expert voices to examine these questions from a variety of perspectives, backgrounds, and traditions. We sought to discover how many of the founding value statements of conservation biology were still current, and if new any ones had supplemented or replaced them. Broad initial momentum from a wide range of contributors soon met with the headwinds of the COVID-19 pandemic, but we eventually emerged with 34 global contributors representing a diverse array of viewpoints. The contributed pieces range from philosophical investigations of value in Nature, applied conservation ethics for endangered species, the rights and roles of Indigenous peoples, macroevolutionary processes of mass extinction, human well-being and social justice, the history of colonialism in conservation, and subtle cultural differences between global powers with respect to Nature. All speak to often unstated values in conservation science. Finally, we offer some questions of our own stemming from these contributions that might provide new or expanded avenues for investigation.