ABSTRACT
There is no doubt that the most distinctive feature of formal thought stems from the role played by statements about possibility relative to statements about empirical reality. Thus, compared to concrete thought, formal thought constitutes a new equilibrium, one that can now be analyzed from the two perspectives just outlined: the extension of the cognitive field that it entails, and the coordinating instruments operative in its functioning. However, we will first analyze briefly the equilibrium characteristics of the stages prior to formal thought.
