There is no question here respecting forms of government, for there is no reason why the Church should not approve of the chief power being held by one man or by more, provided only it be just, and that it tend to the common advantage. Wherefore, so long as justice be respected, the people are not hindered from choosing for themselves that form of government which suits best either their own disposition, or the institutions and customs of their ancestors.
But as regards political power, the Church rightly teaches that it comes from God, for it finds this clearly testified in the Sacred Scriptures and in the monuments of antiquity; besides, no other doctrine can be conceived which is more agreeable to reason or more in accord with the safety of both princes and peoples.- Diuturnum (On Civil Government), paragraphs 7 & 8 (1881).