It follows from these positions that every nation must refuse fealty to an irreligious or contumacious ruler.

In the last resort they may lawfully remove him by murder; and they are _ipso facto_ in a state of mortal sin if they elect or recognize a heretic as sovereign.

This theory sprang from the writings of the English Jesuits, Allen and Parsons.

It was elaborated in Rome by Cardinal Bellarmino, applied in Spain by Suarez and Mariana, and openly preached in France by Jean Boucher.

The best energies of Paolo Sarpi were devoted to combating the main position of ecclesiastical supremacy.