Nuel Belnap on Indeterminism and Free Action

Volume 2 of the series Outstanding Contributions to Logic pp 291-314

Open Access This content is freely available online to anyone, anywhere at any time.


Connecting Logics of Choice and Change

  • Johan van BenthemAffiliated withInstitute for Logic, Language and Computation (ILLC), University of Amsterdam Email author 
  • , Eric PacuitAffiliated withDepartment of Philosophy, Skinner Building, University of Maryland


This chapter is an attempt at clarifying the current scene of sometimes competing action logics, looking for compatibilities and convergences. Current paradigms for deliberate action fall into two broad families: dynamic logics of events, and STIT logics of achieving specified effects. We compare the two frameworks, and show how they can be related technically by embedding basic STIT into a modal logic of matrix games. Amongst various things, this analysis shows how the attractive principle of independence of agents’ actions in STIT might actually be a source of high complexity in the total action logic. Our main point, however, is the compatibility of dynamic logics with explicit events and STIT logics based on a notion that we call ‘control’—and we present a new system of dynamic-epistemic logic with control that has both. Finally, we discuss how dynamic logic and STIT face similar issues when including further crucial aspects of agency such as knowledge, preference, strategic behavior, and explicit acts of choice and deliberation.


Logic of action Stit theory Dynamic logic Dynamic-epistemic logic Strategic games Control