"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."

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If men were wise they would see that the affection that God has implanted in us is amply sufficient, when not weakened by artificial aid, to ensure permanence of union; and if they would have more faith in this all would go well. To tie together by human law what God has tied together by passion, is about as wise as it would be to chain the moon to the earth lest the natural attraction existing between them should not be sufficient to prevent them flying asunder.

— Herbert Spencer