Defeasibility applied to Forrester’s paradox
DOI:
https://doi.org/10.18489/sacj.v32i2.848Abstract
Deontic logic is a logic often used to formalise scenarios in the legal domain. Within the legal domain there are many exceptions and conflicting obligations. This motivates the enrichment of deontic logic with not only the notion of defeasibility, which allows for reasoning about exceptions, but a stronger notion of typicality that is based on defeasibility. KLM-style defeasible reasoning is a logic system that employs defeasibility while Propositional Typicality Logic (PTL) is a logic that does the same for the notion of typicality. Deontic paradoxes are often used to examine logic systems as the paradoxes provide undesirable results even if the scenarios seem intuitive. Forrester’s paradox is one of the most famous of these paradoxes. This paper shows that KLM-style defeasible reasoning and PTL can be used to represent and reason with Forrester’s paradox in such a way as to block undesirable conclusions without completely sacrificing desirable deontic properties.
Downloads
Published
Issue
Section
License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Copyright of all work published here subsists in the authors. While SACJ retains right of first publication, subsequent re-publication is expressly permitted provided the original SACJ publication is acknowledged and cited, according to the terms detailed below. If plagiarism is detected during review, a paper may be summarily rejected and will not be accepted unless even minor infringements are corrected. Should plagiarism be detected after a paper is published, the Editor reserves the right to withdraw a paper from publication. We expect authors to be honest in representing work as their own, and to respect the time and effort our reviewers put in without an undue burden of policing plagiarism, and hence take violations seriously. SACJ applies the Creative Commons Attribution NonCommercial 4.0 License (CC BY-NC 4.0) to all papers published in this journal. Authors who publish with SACJ agree to the following:- Authors retain copyright and grant SACJ right of first publication. The work is additionally licensed under a Creative Commons Attribution Non-Commercial License that requires others who share the work to acknowledge the work’s authorship and initial publication in SACJ. Should anyone else wish to make commercial use of the work, SACJ cedes the right to the author to negotiate terms and does not expect to be paid any royalties.
- Authors may enter into additional arrangements for non-exclusive distribution of the SACJ-published version of the work (e.g., post it to a repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are required to refrain from posting their work online prior to completion of reviews so as not to compromise double-blind reviewing or confuse plagiarism checks.