David Kellogg Lewis (1941-2001) was one of the most influential philosophers of the twentieth century. He made significant contributions to almost every area of analytic philosophy including metaphysics, philosophy of language, philosophy of mind, and philosophy of science, and set the agenda for various debates in these areas which carry on to this day. In several respects he remains a contemporary figure, yet enough time has now passed for historians of philosophyto begin to study his place in twentieth century thought. His philosophy was constructed and refined not just through his published writing, but also crucially through his life-long correspondencewith fellow philosophers, including leading figures such as D.M. Armstrong, Saul Kripke, W.V. Quine, J.J.C. Smart, and Peter van Inwagen. His letters formed the undercurrent of his published work and became the medium through which he proposed many of his well-known theories and discussed a range of philosophical topics in depth.A selection of his vast correspondence over a 40-year period is presented here across two volumes. As metaphysics is arguably where Lewis made hisgreatest contribution, this forms the focus of Volume 1. Arranged under the broad areas of Causation, Modality, and Ontology, the letters offer an organic story of the origins, development, breadth,and depth of his metaphysics in its historical context, as well as a glimpse into the influence of his many interlocutors. This volume will be an indispensable resource for contemporary metaphysics and for those interested in the Lewisian perspective.

Helen Beebee is the Samuel Hall Professor of Philosophy at the University of Manchester and an Honorary Professor at the University of Sydney. She was Principal Investigator on the AHRC-funded project, 'The Age of Metaphysical Revolution: David Lewis and His Place in the History of Analytic Philosophy', from 2016 to 2019. She has published books on Hume and free will, as well as an accessible introduction to philosophy -- Philosophy: Why it Matters (withMichael Rush, Polity 2019).A.R.J. Fisher is Visiting Lecturer at the University of Washington and an Honorary Research Fellow at the University of Manchester. He received his PhD from Syracuse University in 2012. He specializes in metaphysics and the history of analytic philosophy. For the last five years he has extensively studied the David Lewis Papers at Princeton University and has worked on the AHRC-funded project 'The Age of Metaphysical Revolution: David Lewis and His Place in the History of Analytic Philosophy'.