It’s logical

“Just as in logic, we can see a sort of reaction of the form of the proposition upon its content when the principle of contradiction leads to a simplification and purification of the initial definitions, so in ethics, reciprocity implies a purification of the deeper trend of conduct, guiding it by gradual stages to universality itself. Without leaving the sphere of reciprocity, generosity the characteristic of our third stage allies itself to justice pure and simple, and between the more refined forms of justice, such as equity and love properly so called, there is no longer any real conflict.” – Jean Piaget, The Moral Judgment of the Child (trans. Marjorie Gabain)