 Many buildings erected by the Jesuits still stand, such as the Cathedral of Saint Paul in Macau and the Santisima Trinidad de Paraná in Paraguay, an example of a Jesuit Reduction.Spanish treatment of the indigenous populations provoked a fierce debate at home in 1550–51, dubbed the Valladolid debate, over whether Indians possessed souls and if so, whether they were entitled to the basic rights of mankind.Bartolomé de Las Casas, author of "A Short Account of the Destruction of the Indies", championed the cause of the natives, and was opposed by Sepúlveda, who claimed Amerindians were "natural slaves".