Bishop Ramírez was among those who encouraged the Franciscan missionaries in Mexico to investigate and document the pre-Columbian cultures of the Aztec Empire. He was a defender of the human rights of the Indigenous population. He proposed the substitution of payment in kind and encomiendas to replace the payment of tributes then imposed on the Indians. He ordered the construction of an aqueduct to supply Mexico City. He pacified the country and organized the laws, paving the way for the arrival of the first viceroy, Don Antonio de Mendoza, in 1535.