Alex Broadbent: Prediction and Medicine

Abstract

"Historian of medicine Roy Porter maintains that the position of medicine in society has had, and still has, little to do with its ability to make people better. There is a line of thinking in both history and philosophy of medicine that we might call medical nihilism (following Jacob Stegenga). This view holds that medicine is not what it is cracked up to be. But this view assumes (unlike Porter) that the purpose of medicine is indeed to cure people. In this paper I argue that the core medical competence is not to cure, nor to prevent, but to predict disease. The predictions expected of doctors are both actual and counterfactual: both "When will I get better?" and "What would have happened if I had not taken my medicine?". This "predictive thesis" does a better job than the "curative thesis" at explaining why not all medicine is concerned with curative efforts, and it enjoys considerable historical support from the ancient entanglement of prophesy and medicine and from the fact that medicine thrived for centuries with almost no effective cures, and continues to thrive today in various non-Western and complimentary forms that are mostly without curative efficacy. I also argue that it relieves medicine of the pretences of potency that generate the anger implicit in the arguments for medical nihilism. This view also affects expectations of epidemiology, which is sometimes criticised for cataloguing predictive risk factors whose causal relation to the outcome is unclear, instead of identifying decisive interventions. Finally I ask whether this descriptive thesis about the nature of medicine offers any normative lessons for the development of medicine."