As discussed in the previous chapter, in seventeenth-century Spain the traditional concept of universal harmony as the core of politics was updated and reinterpreted both by supporters of a constitutional view of the monarchy and by defenders of absolute rule, who were influenced by the current theories on the reason of state. The ideology that emanated from the Council of Trent heavily influenced the political scene, so religion was never reduced to a political tactic, as Machiavelli had done in The Prince: the monarch, in all cases, was meant to pursue the common good, as well as peace and justice in the Christian community. Spanish theorists generally expressed concern for the protection of the ‘true religion’ and for the salvation of the king's soul. Political power emanated from God in the last instance, with or without the intermediation of the community, and the perfect king was consistently portrayed as a defensor fidei and the likeness or simulacrum of God on earth; an architect of harmony who maintained order despite the instability of the times and the mutability of earthly affairs.

All positions in the political writing scene at the time stated that the king ought to be ultimately responsible for the state, and focused his harmonizing role around three main virtues: prudence, justice and mercy.