A Contractualist Argumentation Framework for Moral Decision-Making
2026-08-03 • Artificial Intelligence
Artificial IntelligenceComputers and Society
AI summaryⓘ
The authors propose a way for smart agents, like robots or software, to make moral choices when their actions affect different people with different interests. They base their method on a moral theory called contractualism, which says actions are okay if no one could reasonably reject the rules behind them. To make this practical, they use a system that builds and compares arguments, factoring in each agent's values to decide what counts as morally important. They show how this works with an example at home and relate it to similar argument-based methods.
Autonomous agentsContractualismMoral decision-makingASPIC+Structured argumentationValue-based filteringArgumentation semanticsEthical theoryMulti-agent systems
Authors
Luis Marcos-Vidal, Giulio Antonio Abbo, Tony Belpaeme
Abstract
Autonomous agents operating in shared environments must make decisions that affect multiple individuals with potentially conflicting interests. We propose a formal framework for moral decision-making grounded in Scanlon's contractualism, an ethical theory that evaluates the permissibility of actions in terms of principles that no one could reasonably reject. To operationalise contractualist reasoning, we use ASPIC+, a structured argumentation framework, extended with value-based filtering to model how each agent's values determine which reasons are morally relevant in the first place. The result is a Contractualist Argumentation Framework in which agents' reasons are formally represented, compared, and evaluated through argumentation semantics. We illustrate the approach through a worked example in a domestic setting and discuss its relation to existing value-based argumentation approaches.