Health, homeostasis, and the situation-specificity of normality.

Christopher Boorse's Biostatistical Theory of Health has been the main contender among naturalistic accounts of health for the last 40 years. Yet, a recent criticism of this theory, presented by Elselijn Kingma, identifies a dilemma resulting from the BST's conceptual linking of health and statistical typicality. Kingma argues that the BST either cannot accommodate the situation-specificity of many normal functions (e.g., digestion) or cannot account for many situation-specific diseases (e.g., mountain sickness). In this article, we expand upon with Daniel Hausman's response to Kingma's dilemma. We propose that recalling Boorse's specification that health is an intrinsic property of its bearers and explicating this intrinsic property in relation to the concept of homeostasis can illuminate how proponents of naturalistic accounts of health should deal with the situation-specificity of normal functions. We argue that beyond what Boorse and Hausman have delineated, the situation-specificity of normal function cannot be fully captured in a simple dichotomy between normal and abnormal environment or between relevant and irrelevant situations. By bringing homeostasis to the fore of the analysis of health, we set out a richer picture of what the various situations that affect living organisms' functional performance can be. Accordingly, we provide a broader classification of these various situations which, we contend, better accounts for the main intuitions that philosophers of medicine have sought to accommodate than previous naturalistic theories of health.