To do something means to transform one's environment, society, humans, matter or information, at a specific moment in History, with the intention of improving or of repairing something.

For the action to be legitimate, the collective that engages in it must have mobilised all its resources to make sure that this action effectively contributes to reaching the claimed goal (technical validity of action) and that the interests, moral points of view and values of all relevant human and non-human (from plants and animals to the climate) stakeholders, current and future, were respected (political and moral legitimacy of action).

By engaging in an action, by setting it in History, a collective is confronted to questions that find no answer in moral or scientific authority or in any form of universal truth, and that can only be solved through a thorough and well-argued discussion between the people involved:

• what are the priority objectives to reach, the most important problems and issues to solve?
• is the information available sufficient to act, or is it preferable to take time to gather more, or to let the situation evolve spontaneously, with the risk of letting the appropriate moment for action slip away?
• what will be the predictable consequences of the action, in the current state of knowledge, and what judgement should be held on them, knowing that these consequences bear upon different and heterogeneous areas, time scales and categories of stakeholders, which may not be boiled down to a single "optimisation" scale?