School of Salamanca
Tomás de Mercado, a Sevillian who died in 1575, continued in the tradition of the School of Salamanca and when young went to Mexico. His vision of Spain's economic problems took into account the Indies. He became a Dominican friar in 1553, earning a doctorate in theology and standing out as a moralist. He reflected on the ethics of commercial relations and on returning to Spain he taught at the universities of Seville and Salamanca. In 1569 he published "Sum of deals and contracts", that was reedited two years later. It describes the mercantile uses of the time in Seville and Medina del Campo. This work reflects on the foundation of interest praising the ethical uses of finances and counter to the restrictive interpretation of the Catholic Church that deemed it usury. The analysis raises and deepens the quantitative theory of money from the tradition of the School of Salamanca, especially with regard to the international circulation of foreign currency.