This chapter offers a philosophical diagnosis of the challenges that medicine is facing, regarding medically unexplained symptoms and complex illnesses.
We propose that a crucial problem comes from applying a Humean regularity theory of causality, in which a cause is understood as something that always provokes the same effect under ideal conditions, to the clinical reality, where no ideal condition, or average patient, can ever be found.
A dispositionalist understanding of causality proposes instead to start from the particular and unique situation of the single case in order to understand causality.
The medical evidence, including causally relevant evidence, must then be generated starting from the single patient. This includes not only the patient’s medical data, but also the patient’s condition, narrative and perspective.
This is fundamental in order to generate causal hypotheses about the complex situation and all the dispositions that influence the medical condition.
Ultimately, evidence from the clinical encounter could assist the design of experiments both in the lab and in the clinics. The best approach to causality, we argue, is to use a plurality of methodologies.
We also explain how, when starting from a dispositional theory of causality, heterogeneity, unexpected results and outlier cases actually represent an epistemological advantage, instead of an obstacle, for the causal enquiry.
