Arguing about constitutive and regulative norms

Abstract

Formal arguments are often represented by (support, conclusion) pairs, but in this paper we consider normative arguments represented by sequences of (brute, institutional, deontic) triples, where constitutive norms derive institutional facts from brute facts, and regulative norms derive deontic facts like obligations and permissions from institutional facts. The institutional facts may be seen as the reasons explaining or warranting the deontic obligations and permissions, and therefore they can be attacked by other normative arguments too. We represent different aspects of normative reasoning by different kinds of consistency checks among these triples, and we use formal argumentation theory to resolve conflicts among such normative arguments. In particular, we introduce various requirements for arguing about norms concerning violations, contrary-to-duty obligations, dilemmas, conflict resolution and different kinds of norms, and we introduce a formal argumentation theory satisfying the requirements. In order to illustrate our framework, we introduce a running example based on university regulations for prospective and actual students.

Keywords:

• Normative reasoning
• deontic logic
• argumentation
• input/output logic

Acknowledgments

We thank two anonymous referees for valuable comments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 Such detachments are used to axiomatise so-called reusable combination of constitutive and regulative norms, see the paper of Sun and van der Torre for further details.

2 This example has been suggested by one of the anonymous reviewers, whom we thank.

Additional information

Funding

The contribution of Gabriella Pigozzi was supported by the project AMANDE ANR-13-BS02-0004 of the French National Research Agency (ANR). Leendert van der Torre has received funding from the European Union's H2020 research and innovation programme under the Marie Curie grant agreement No. 690974 for the project MIREL: MIning and REasoning with Legal texts.