The concept of health resides in a space bounded by two other concepts. On one side, there is the terrain contested by the concepts of health and disease. While there is controversy regarding where and how to draw the boundary between health and disease, very few theorists deny that such a boundary exists. On the other side of health, as it were, is the concept of well-being. 

Here, however, doubt exists as to whether the boundary is meaningful at all, since some theories appear to define health in a way that makes it co-extensive with well-being. It is argued that it is worth attempting to maintain a distinction between these concepts by embracing a negative theory of health, wherein health is understood as the absence of disease. In this view, a diseased system is one in which subsystems fail to carry out their assigned biological functions. The paper addresses common objections to negative theories and suggests that their main appeal lies in the way they enable us to separate questions of well-being from questions of function and regulation. Additionally, it explains why such a separation should be embraced.

Dominic Murphy is Professor of Philosophy and Head of School at the University of Sydney’s School of History and Philosophy of Science. His primary areas of interest lie in the philosophy of cognitive and biological sciences, particularly issues in psychiatry and cognitive neuroscience. He also has a broad range of interests encompassing evolutionary theory, the history and philosophy of biology and medicine, moral psychology, epistemology, and bioethics.