The main concern of this work is to present the thought of the Augustinians living in San Agustin Monastery in Manila about the early pacification of the Islands; their labor to see to it that pacification was carried out in accordance with the instructions of the King; how they were present in all the pacifying expeditions or thought about the justice of wars waged against the natives, tributes and "slavery". The study is limited to the thought of the Augustinians as might be gleaned in the different letters and other documents of the same, especially those written by Fr. Martin de Rada, as well as the ones written by Governors and officials of the Philippines. It used a historical approach.