 In his lecture On Civil Power (De potestate civili), Vitoria holds that every power, public or private, comes from God and cannot be abolished by human beings, not even if they are in full consensus. Vitoria’s ideas about society depended partly on his Aristotelian belief that human beings are social by nature, needing others to survive and achieve a good life. Thus, a natural good, survival, not moral goodness, was its original purpose. Nature, following God’s purpose, had implanted in early peoples the urge to establish households, cities, and regimes. Society eventually came to promote virtues, especially justice and amity, which supported the common good. He followed in a certain sense an Aristotelian line, using the theory of the four causes for his analysis, first of public, then of private power, and starting with the final cause, which was regarded in the Aristotelian and Thomist tradition as the necessary cause. According to Vitoria, “the origin of human cities and commonwealths was not a human invention … but a device implanted by nature in man for his own survival” and for the sake of this it also needs an “ordering force” (ibid., qu. 1, art. 2, p. 9). The efficient cause of public power is God, and its material cause is the commonwealth itself. Royal power is not from the commonwealth, even if the king is elected, but from God himself (ibid., qu. 1 art. 5). Non-Christians have legitimate rulers, and a legitimately constituted power cannot be abolished by the consent of the people (ibid., qu.1. art 6–7).