52 But there is yet another error no less pernicious to the well-being of the nations and to the prosperity of that great human society which gathers together and embraces within its confines all races. It is the error contained in those ideas which do not hesitate to divorce civil authority from every kind of dependence upon the Supreme Being - First Source and absolute Master of man and of society - and from every restraint of a Higher Law derived from God as from its First Source. Thus they accord the civil authority an unrestricted field of action that is at the mercy of the changeful tide of human will, or of the dictates of casual historical claims, and of the interests of a few.
Source: Summi Pontificatus (Vatican.va)