Pope John Paul II, in his encyclical Centesimus annus, makes the following observation:
Pope Leo XIII was aware of the need for a sound theory of the State in order to ensure the normal development of man’s spiritual and temporal activities, both of which are indispensable. For this reason, in one passage of Rerum novarum he presents the organization of society according to the three powers—legislative, executive and judicial—, something which at the time represented a novelty in Church teaching. Such an ordering reflects a realistic vision of man’s social nature, which calls for legislation capable of protecting the freedom of all. To that end, it is preferable that each power be balanced by other powers and by other spheres of responsibility which keep it within proper bounds. This is the principle of the “rule of law”, in which the law is sovereign, and not the arbitrary will of individuals.
The part of this that interests me is the first sentence. Why is a “theory of the state” necessary for the spiritual well-being of humankind? That seems like quite an odd claim, which, if true would seem to imply that vast segments of (Christian) humanity throughout history could not possibly have had access to “normal” spiritual development.