Mixture of assimilation to earlier schemas and adaptation to the actual conditions of the situation is what defines motor intelligence. But — and this is where rules come into existence — as soon as a balance is established between adaptation and assimilation, the course of conduct adopted becomes crystallized and ritualized. New schemas are even established which the child looks for and retains with care, as though they were obligatory or charged with efficacy.

Ch. 1 : The Rules of the Game, § 9 : Conclusions : Motor Rules and the Two Kinds of Respect - The Moral Judgment of the Child (1932)