"To reason logically is so to link one's propositions that each should contain the reason for the one..." — Jean Piaget

All morality consists in a system of rules, and the essence of all morality is to be sought for in the respect which the individual acquires for these rules.

Everyone knows that at the age of 11-12, children have a marked impulse to form themselves into groups and that the respect paid to the rules and regulations of their play constitutes an important feature of this social life.

Before playing with his equals, the child is influenced by his parents. He is subjected from his cradle to a multiplicity of regulations, and even before language he becomes conscious of certain obligations.

The practice of narrative and argument does not lead to invention, but it compels a certain coherence of thought.