Formalizing Reasons, Oughts, and Requirements

  • Robert Mullins orcid logo (The University of Queensland)


Reasons-based accounts of our normative conclusions face difficulties in distinguishing between what ought to be done and what is required. This article addresses this problem from a formal perspective. I introduce a rudimentary formalization of a reasons-based account and demonstrate that that the model faces difficulties in accounting for the distinction between oughts and requirements. I briefly critique attempts to distinguish between oughts and requirements by appealing to a difference in strength or weight of reasons. I then present a formalized reasons-based account of permissions, oughts and requirements. The model exploits Joshua Gert (2004; 2007) and Patricia Greenspan’s (2005; 2007; 2010) suggestion that some reasons perform a purely justificatory function. I show that the model preserves the standard entailment relationships between requirements, oughts and permissions.

How to Cite:

Mullins, R., (2021) “Formalizing Reasons, Oughts, and Requirements”, Ergo 7. doi:



Published on
22 Oct 2021
Peer Reviewed