Bioethics and the Hypothesis of Extended Health.

Dominant views about the nature of health and disease in bioethics and the philosophy of medicine have presumed the existence of a fixed, stable, individual organism as the bearer of health and disease states, and as such, the appropriate target of medical therapy and ethical concern. However, recent developments in microbial biology, neuroscience, the philosophy of cognitive science, and social and personality psychology have produced a novel understanding of the individual and its fluid boundaries. Drawing on converging evidence from these disciplines, and following recent research in public health, we argue that certain features of our biological and social environment can be so tightly integrated as to constitute a unit of care extending beyond the intuitive boundaries of skin and skull. This paper develops and defends the Hypothesis of Extended Health (HEH), which denies the claim that health and disease states are predicated solely on the internal functioning of an organism. If this is correct, then the targets of medical invention and ethical concern are wider and more diverse than is usually assumed.