Juan de Mariana was born in 1536, and is therefore by any reckoning a very late scholastic. Working in the tranquility and freedom of a Spain which had, in 1492, finally been freed from the oppression of Islamic occupational armies, he wrote copiously: one of his works, a history of Spain, was thirty volumes.
Significantly, he wrote in a startling way about political liberty. He advocated freedom of assembly (the freedom of association), and that a government may not arbitrarily spy on its citizens. Like Locke, he asserted that a government’s legitimacy was based on the consent of the governed. Unlike Locke, he did so in the 1500s. Historian Jesús Huerta de Soto writes:
In Spain, although the authorities were not enthusiastic about it, the book was respected. In fact, all Mariana did was to take an idea - that natural law is morally superior to the might of the state - to its logical conclusion. This idea had previously been developed in detail by the great founder of international law, the Dominican Francisco de Vitoria (1485-1546), who began the Spanish scholastic tradition of denouncing the conquest and particularly the enslavement of the Indians by the Spaniards in the New World.
Examining scholastic notions of civil law, Juan de Mariana began to articulate a connection between property rights and other forms of liberty. Against the notion that property rights are somehow low or base, he saw that tyrants inevitably violate property rights, and inasmuch as human effort is spent acquiring property, the tyrant’s confiscation of such property is de facto slavery.
But perhaps Mariana’s most important book was the work published in 1605 with the title De monetae mutatione (On the alteration of money). In this book, Mariana began to question whether the king was the owner of the private property of his vassals or citizens and reached the clear conclusion that he was not. The author then applied his distinction between a king and a tyrant and concluded that “the tyrant is he who tramples everything underfoot and believes everything to belong to him; the king restricts or limits his covetousness within the terms of reason and justice.”
He asserted that the king should not be able to tax, or raise taxes, without the consent of the people. We associate the slogan ‘no taxation without representation’ with Anglo-American sources, but here we find a different and earlier source for the sentiment behind those words.