 Appealing to biblical texts, Campanella maintains that the Spanish sovereign can aspire to the monarchy of the world if he takes inspiration from the model of Cyrus, invested by God, as Isaiah (45.1) confirms, with the mission of liberating the Church from infidels and of bringing together all peoples under a single faith. For the Catholic king the only practical way of achieving his own universal plans is through a firm accord with the Church and with the pope, following the example of Constantine and Charlemagne. Campanella further stresses that religion is the most powerful bond of political unity. Machiavelli, too, had emphasized the strength of this bond, when analyzing the events of the Roman Republic, but then had condemned the Christian religion as a cause of weakness, strife and divisions. Campanella has no doubt that religion, whether true or false, is the primary and most powerful unifying force in the political body, in that it rules over souls and brings them together, and that all other ties between human beings depend on it.