This seminar will bring together senior and junior scholars from philosophy, psychology, government, medicine, public health, and other scientific communities at Harvard and at collaborating institutions to explore a range of different approaches to causality. These approaches differ in what they take causality to be, in what they take to be the best methods for discovering causal facts, and in what they take the proper role of such facts to be in prediction, control, and explanation. Our working hypothesis will be that causality is a multifaceted concept, with (at least) probabilistic, counterfactual, logical, and interventionist aspects. These distinct aspects have motivated, we hypothesize, the strikingly different approaches and theories in philosophy, cognitive science, computer science, and artificial intelligence (AI). We aim to explore the extent to which apparent conflict between these approaches simply reflects the multifaceted nature of the underlying concept. The seminar will have two themes, philosophical and scientific. For the philosophical, we will address central questions in the epistemology, metaphysics, methodology, and semantics of causal notions. For the scientific, we will address the distinctive sorts of problems and progress our participating scientists have found in the use of causal inference in their respective disciplines. The seminar will attempt to integrate these themes by explicitly considering the ways in which abstract philosophical investigation of causality can both guide and be informed by focused scientific work involving causal inference. We thereby hope to encourage dialogue across different disciplines, while beginning to flesh out a new, explicitly pluralistic framework for understanding causality.