1. A method enabling knowledge managers to make a decision after discovery of an abnormality in actual data in an economic, technical, or organizational field, to counteract the abnormality, the method including: creating a system of agents, comprising cognitive agents, creator agents of portable knowledge objects, and constructor agents of knowledge objects, by addition of supplementary knowledge elements to created knowledge objects; causing the system of agents to start a decision-making process following the discovery of an abnormality in actual data of the field of application by creation of an initial knowledge object representing an alarm index; establishing a plurality of decisional paths lied to the knowledge object under different points of view established by different agents, each agent working in a field corresponding to the point of view for which a decisional path is established; merging the decisional paths; and making a decision, following merging of the decisional paths, and counteracting the abnormality discovered, wherein the decision-making process reaches a final decision stage by passing through a first stage called presumption, constituting a weak switch in reasoning, reflecting a simple trend, and a strong switch decision stage, which clearly indicates direction in which the reasoning must progress.