International audienceIn the recent literature in Artificial Intelligence, ethical issues are increasingly discussed. Many proposals of ethical agents are made. However, those approaches consider mainly an agent-centered perspective, letting aside the collective dimension of multi-agent systems. For instance, when considering cooperation among such agents, ethics could be a key issue to drive the interactions among the agents. This paper presents a model for ethics-based cooperation. Each agent uses an ethical judgment process to compute images of the other agents' ethical behavior. Based on a rationalist and explicit approach, the judgment process distinguishes a theory of good, namely how values and moral rules are defined , and a theory ...