A major focus of the philosophy of medicine and, in general, of the philosophy of science has been the interplay of facts and values. Nowhere is an evaluation of this interplay more important than in the ethics of diagnosis. Traditionally, diagnosis has been understood as an epistemological activity which is concerned with facts and excludes the intrusion of values. The essays in this volume challenge this assumption. Questions of knowledge in diagnosis are intimately related to the concerns with intervention that characterize the applied science of medicine. Broad social and individual goals, as well as diverse ethical frameworks, are shown to condition both the processes and results of diagnosis. This has significant implications for bioethics, implications that have not previously been developed. With this volume, `the ethics of diagnosis'' is established as an important branch of bioethics.