From Pope St. John Paul II’s Apostolic Exhortation Familiaris Consortio (1981):
Just as the intimate connection between the family and society demands that the family be open to and participate in society and its development, so also it requires that society should never fail in its fundamental task of respecting and fostering the family.
The family and society have complementary functions in defending and fostering the good of each and every human being. But society—more specifically the State—must recognize that “the family is a society in its own original right”111 and so society is under a grave obligation in its relations with the family to adhere to the principle of subsidiarity.
By virtue of this principle, the State cannot and must not take away from families the functions that they can just as well perform on their own or in free associations; instead it must positively favor and encourage as far as possible responsible initiative by families. In the conviction that the good of the family is an indispensable and essential value of the civil community, the public authorities must do everything possible to ensure that families have all those aids—economic, social, educational, political and cultural assistance—that they need in order to face all their responsibilities in a human way.
111 Second Vatican Council Dignitatis humanæ, 5.
— Familiaris Consortio 45