Therefore since all men are free by nature, every government that restrains its subjects from evils and uses the fear of punishment to orient their freedom towards the good, whether it consists of written laws or of a living law in the person of the prince, is constituted only by the agreement and consent of the subjects. For if by nature men are equally powerful and equally free, then the true and well-ordered authority of one who is a fellow and equal in power can only be established by the choice and consent of others, just as laws are established by consent

The Catholic Concordance