Causality is the cognitive cement of the universe. It is a central notion in the representation of action that governs the observed behavior in many differ­ent species. It links even­tualities and predicts the consequences of action. It is the origin of beha­viors that allows ani­mals, notably humans, to act upon and thus shape their environment. Causality is also the cognitive basis for the acquisition and the use of categories and concepts in the child. As such, it is the basis for rationality