Uncertain Machine Ethics Planning
Simon Kolker, Louise A. Dennis, Ramon Fraga Pereira, Mengwei Xu
TL;DR
The paper tackles planning under both outcome and moral uncertainty in machine ethics by formalizing uncertain ethical planning as MMMDP/MMSSP and applying MEHR within a Multi-Objective AO* framework. It introduces a running insulin-theft case to demonstrate how conflicting moral theories can be modeled, reasoned about, and comparatively evaluated using history-based arguments and attacks. The main contributions are the MMMDP/MMSSP formalism, the MEHR-based argumentation mechanism for policy selection, and a two-stage Moral Planner that first finds Pareto-undominated policies and then selects the ethically preferable one under a budgeted, non-moral cost. The work advances explainability in ethical AI by grounding decisions in reproducible argumentative structures, while highlighting computational challenges and avenues for efficiency improvements and broader application.
Abstract
Machine Ethics decisions should consider the implications of uncertainty over decisions. Decisions should be made over sequences of actions to reach preferable outcomes long term. The evaluation of outcomes, however, may invoke one or more moral theories, which might have conflicting judgements. Each theory will require differing representations of the ethical situation. For example, Utilitarianism measures numerical values, Deontology analyses duties, and Virtue Ethics emphasises moral character. While balancing potentially conflicting moral considerations, decisions may need to be made, for example, to achieve morally neutral goals with minimal costs. In this paper, we formalise the problem as a Multi-Moral Markov Decision Process and a Multi-Moral Stochastic Shortest Path Problem. We develop a heuristic algorithm based on Multi-Objective AO*, utilising Sven-Ove Hansson's Hypothetical Retrospection procedure for ethical reasoning under uncertainty. Our approach is validated by a case study from Machine Ethics literature: the problem of whether to steal insulin for someone who needs it.
