John Mary Harty

"Though Catholic doctrine condemns tyrannicide as opposed to the natural law, formerly great theologians of the Church like St. Thomas, Suarez, and Bañez, O.P., permitted rebellion against oppressive rulers when the tyranny had become extreme and when no other means of safety were available. This merely carried to its logical conclusion the doctrine of the Middle Ages that the supreme ruling authority comes from God through the people for the public good. As the people immediately give sovereignty to the ruler, so the people can deprive him of his sovereignty when he has used his power oppressively."