Most philosophical work on causation is divorced from scientific practice, but in this book David Papineau develops a theory based on systems of directed regularities in order to provide a principled grounding for the science of causal inference. His book first introduces non-specialists to the techniques of causal inference, and then shows how the resulting theory can account for all aspects of causation. While Papineau draws on a wide range of scientific and philosophical sources, everything is explained from first principles and will be accessible to readers from all backgrounds. The resulting theory marks a new departure in the philosophy of causation, and will be of interest not only to philosophers but also to anybody interested in the statistical techniques that are widely used throughout science to analyse causal structures.