 Suárez believed that individual peoples reached agreement on the need for government. God then granted rulers power to direct humanity toward its proper ends. Critics of his thought like Robert Filmer objected to bringing in God at this late stage, in order to explain the formation of regimes, rather than emphasizing his role in the creation of commonwealths since Adam (Filmer 1680: chap. II 2). Suárez thought that it was the responsibility of the ruler to promote harmony between subjects, to exercise power well, and to enact laws to perfect the community. He also treated the relationship of law to conscience and that of ecclesiastical to lay powers. Like many representatives of Spanish Scholasticism, Suárez favored monarchy, within limits, as the best regime. Individuals had the right to self-defense, as did the society as a whole, and they might resist a ruler who acted badly. Suárez even contemplated the possibility that tyrants could be killed for threatening the survival of the commonwealth. In his polemics against King James I of England, he argued for the immunity of the Church from control by lay regimes. The English oath, the so-called oath of allegiance that King James had required his subjects to take in 1606, the year after the Gunpowder Plot, he said, violated this immunity and undermined obedience to the Roman pontiff in spiritual matters. Suárez was willing to believe that the pope could exhort the people to rise up against a tyrant or to invoke the aid of outsiders against one. Except in such cases, however, Christians were to obey their lay rulers in conformity with natural law. This right to resistance was widely taken for granted by the Jesuits and considerably expanded by Juan de Mariana (1536–1624). Although recent scholarship has cast doubt on the traditional labeling of Mariana as an early exponent of popular sovereignty (Braun 2007), the Catholic zealot who assassinated Henry IV of France in 1610 is known to have referred to his writings. 