Abstract : We realize a study of the impact of ethical messages grouping on the decision process of two types of legal auditors (CPA and aeronautical auditors) and the decision of HR executives. Grounding the research on a definition of ethics and on a moral psychology paradox, we present the central role of messages in the decision context. The design of the research shows a significant difference of perception and reaction between the tree different populations. The explicit messages and the difficulty to decide are the most import factors used for decision. It seems necessary to update some decision models and audit models, in order to add the concepts of ethical messages and internal independence.