Abstract

Identifying the necessary and sufficient conditions for individuating and classifying diseases is a matter of great importance in the fields of law, ethics, epidemiology, and of course medicine. In this paper I first propose a means of achieving this goal, ensuring that no two distinct disease-types could correctly be ascribed to the same disease-token. I then posit a metaphysical ontology of diseases - that is, I give an account of what a disease is. This is essential to providing the most effective means of interfering with disease processes. Following existing work in the philosophy of medicine and epidemiology, philosophy of biology, conditional analyses of causation, and recent literature on dispositional essentialism, I endorse a dispositional conception of disease whereby diseases are individuated by their causes, and diseases are causal processes best seen as simultaneously acting sequences of mutually manifesting dispositions - this, I claim, follows from the assumption that diseases should be classified by consideration of both their clinical and pathological effects, and importantly, events that can lead to the cessation of these symptoms.