In this introduction to the Outstanding contributions to logic volumedevoted to Nuel Belnap’s work on indeterminism and free action, we provide abrief overview of some of the formal frameworks and methods involved in Belnap’swork on these topics: theories of branching histories, specifically “branchingtime” and “branching space-times”, the stit (“seeing to it that”) logic of agency, andcase-intensional first order logic. We also draw some connections to the contributionsincluded in this volume. Abstracts of these contributions are included as anappendix.Nuel Belnap’s work in logic and in philosophy spans a period of over half a century.During this time, he has followed a number of different research lines, most of themover a period of many years or decades, and often in close collaboration with otherresearchers:1 relevance logic, a long term project starting from a collaboration withAlan Anderson dating back to the late 1950s and continued with Robert Meyerand Michael Dunn into the 1990s; the logic of questions, developed with ThomasSteel in the 1960s and 1970s; display logic in the 1980s and 1990s; the revisiontheory of truth, with Anil Gupta, in the 1990s; and a long-term, continuing interestin indeterminism and free action. This book is devoted to Belnap’s work on the lattertwo topics. In this introduction, we provide a brief overview of some of the formalframeworks and methods involved in thatwork, and we drawsome connections to thecontributions included in this volume. Abstracts of these contributions are presentedin Appendix A.

This book is included in DOAB.