The success-failure inversion in modern medicine.

Twentieth-century medicine was most successful against diseases sharing a particular causal architecture: a discrete lesion standing in a relation of approximate necessity and sufficiency to a clinical syndrome, amenable to specific perturbation. Mortality from acute myocardial infarction has fallen by nearly 90 percent in the United States since 1970; pediatric leukemia has become survivable; HIV has become chronic. That success has shifted the residual burden toward conditions with a different architecture-late-life neurodegeneration, multimorbidity, frailty, idiopathic neuropathy-in which pathology is distributed across scales, and no single node carries the necessity that targeted intervention requires. The failure is not that medicine has extended life. It is that biomedical institutions have not adapted to the forms of vulnerability that accompany longer lives, and the non-adaptation is structural rather than accidental. This paper asks why: why funding and evaluation systems systematically favor research on discrete diseases and individual molecular targets over integrated research on aging as a systemic, multiscale, temporally extended process. We distinguish two levels at which the apparatus fragments its object.