Introduction: Evidence and Causality in the Sciences

Abstract

Causality is a vibrant and thriving topic in philosophy of science. It is closely related to many other challenging scientific concepts, such as probability and mechanisms, which arise in many different scientific contexts, in different fields. For example, probability and mechanisms are relevant to both causal inference (finding out what causes what) and causal explanation (explaining how a cause produces its effect). They are also of interest to fields as diverse as astrophysics, biochemistry, biomedical and social sciences. At the same time, there has been an explosion of interest in evidence, most obviously in biomedical contexts with the rise of ‘evidence-based medicine’, but also elsewhere, such as in social science. What is evidence? How do we decide what our best sources of evidence are? This topos examines the relation between causality and evidence in different scientific areas. This involves questions about the foundations of the sciences, e.g. what is evidence and how does it contribute to causal knowledge? But it also involves questions about specific applications, e.g. how should we best deal with the many problems of evidence given by expert witnesses in court; and questions about policy-making, e.g. what constitutes evidence of causation that is relevant to the design of socio-economic and public health policies? These questions are all of immense current concern. Pressure on health systems from challenges such as ageing populations and the obesity epidemic, coupled with severe financial constraints on public policy, means governments are demanding answers with increasing urgency. The time is ripe for a thorough discussion on causality and evidence. The contributions collected here are but the starting point, and we hope they will inspire many other scholars to engage with these topics, from either a philosophical or scientific angle.