Signal A Contractualist Argumentation Framework for Moral Decision-Making

Summary

Luis Marcos-Vidal, Giulio Antonio Abbo, and Tony Belpaeme published a paper on arXiv (cs.CY) on August 3, 2026, proposing a formal framework for moral decision-making by autonomous agents grounded in Scanlon's contractualism, an ethical theory that evaluates the permissibility of actions based on principles no one could reasonably reject. The framework addresses situations where autonomous agents operating in shared environments must make decisions affecting multiple individuals with potentially conflicting interests. To operationalize contractualist reasoning, the authors use ASPIC+, a structured argumentation framework, extended with value-based filtering that models how each agent's values determine which reasons are morally relevant in the first place. The result is what the authors call a Contractualist Argumentation Framework, in which agents' reasons are formally represented, compared, and evaluated through argumentation semantics. The authors illustrate the approach through a worked example in a domestic setting and discuss its relationship to existing value-based argumentation approaches.