Nuel Belnap on Indeterminism and Free Action

Thomas Müller

In this introduction to the Outstanding contributions to logic volume devoted to Nuel Belnap’s work on indeterminism and free action, we provide a brief overview of some of the formal frameworks and methods involved in Belnap’s work on these topics: theories of branching histories, specifically “branching time” and “branching space-times”, the stit (“seeing to it that”) logic of agency, and case-intensional first order logic. We also draw some connections to the contributions included in this volume. Abstracts of these contributions are included as an appendix. 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 them over a period of many years or decades, and often in close collaboration with other researchers:1 relevance logic, a long term project starting from...