The Manila Synod of 1582
In 1582, Domingo de Salazar (1521 to 1594), the first bishop of Manila called for an assembly of clerics, missionaries, and laypeople to discuss the status of the Philippine islands under the Spanish Crown.
This assembly which will be known as the Manila Synod of 1582 tackled various social issues and arrived at some of the following considerations:
The Spanish officials cannot collect tribute from areas that receive no religious (Catholic) instruction.
The tribute collected must be used for the improvement of the native areas that gave them.
That restitution must be made by the conquistadores who abused the natives. This means returning whatever they stole (e.g., goods and land) to the victims on pain of not receiving the Holy Sacraments.
Connected to this is the fund (caja de restituciones) established to pay injured parties.
That the rights of non-Christian and Christian natives be recognized as natural and inalienable.
The encomienda system (right to collect tribute from the natives) must mainly be done for the sake of the natives and not the Spanish encomenderos. The encomenderos are not to be considered lords of the natives, as their job is to be the native peoples' advocates, instructors, and protectors.
For further reading:
The Manila Synod of 1582: The Draft of Its Handbook for Confessors by Paul A. Dumol
Readings in Philippine History by Horacio de la Costa, S.J.
Growth and Decline: Essays in Philippine History by John N. Schumacher, S.J.