This collection offers an in-depth look at Cora Diamond's distinctive approach to ethics and its philosophical significance. It comprises a new essay by Cora Diamond on the policing of concepts, followed by ten original chapters by world-class scholars covering conceptual loss, moral theory, the category of the human, the moral consideration of animals, and the meaning of narcissism. Including comparisons to the work of other contemporary moral philosophers such as Martha Nussbaum, Jeff McMahan, Rai Gaita, Eva Kittay, Christine Korsgaard, and Edward Harcourt, the volume also creates interdisciplinary links between Diamond's work and other fields of study, including psychoanalysis and contemporary ethology. Showcasing the vital importance of Diamond's contribution to philosophy, this volume is essential reading for scholars working in ethics, philosophy of language and literature.