10 The Fathers of the Church have taken great care to proclaim and propagate this very doctrine in which they had been instructed. "We do not attribute," says St. Augustine, "the power of giving government and empires to any but the true God."(10) On the same passage St. John Chrysostom says: "That there are kingdoms, and that some rule, while others are subject, and that none of these things is brought about by accident or rashly . . . is, I say, a work of divine wisdom."(11) The same truth is testified by St. Gregory the Great, saying: "We confess that power is given from above to emperors and kings."(12) Verily the holy doctors have undertaken to illustrate also the same precepts by the natural light of reason in such a way that they must appear to be altogether right and true, even to those who follow reason for their sole guide.
Source: Diuturnum (Vatican.va)