In-between states of potential pathology—or "borderline cases"—are a crucial feature of present-day medicine. The ways in which unsettled in-between states have been conceptualized and dealt with has structured much of public and private medical research, patient awareness, and health care regulation. This project explores the interconnections between challenges to drawing boundaries around assumed disease entities and debates on validating medical diagnosis and interventions. To this end, we study how borderline cases have been addressed throughout the period of modern medicine—with examples ranging from the beginning of systematic psychiatric classification in the late-nineteenth century to the contemporary promises of precision medicine. Instead of taking borderline cases as test cases to defend one or another philosophical account of what should count as disease, this project defends a relational epistemology to medical issues: if we acknowledge that understandings of a disease can legitimately differ in various individuals and communities, new philosophical questions arise that focus not so much on the right definition, but on the relationship between understandings.
This project also aims at a methodological contribution to the integration of history and philosophy of medicine. It brings together scholarship and methods from both established and new research approaches, including historical epistemology, philosophy of science in practice, philosophy in medicine, and feminist epistemologies.