The relations between parents and children are certainly not only those of constraint. There is spontaneous mutual affection, which from the first prompts the child to acts of generosity and even of self-sacrifice, to very touching demonstrations which are in no way prescribed. And here no doubt is the starting point for that morality of good which we shall see developing alongside of the morality of right or duty, and which in some persons completely replaces it.

Ch. 2 : Adult Constraint and Moral Realism - The Moral Judgment of the Child (1932)