The purpose of this paper is to discuss, through a discoursive perspective, some historical and political elements concerning the jesuits’ policies for the conversion of the indian tribes during the brazilian colonial period, considering that they contributed to the development of the so called general languages (specially, but not only, the Nheengatu and the Língua Geral Paulista). One of the outstandig characteristics of the missionary strategies is related to a compromise between a millenarian belief and the natural right, as both those conceptions stood as the cornerstone for their Modus Operandi towards the land, the indians and also the portuguese administration. As the tupinamba language was the main instrument widely used as a means to fulfill the colonist purposes, and as there was a close relationship between the portuguese crown imperialistic interests and the christianization objectives of the Companhia de Jesus, at least in the early begining of the colonization process, it’s reasonable to assume that the colonization policy carried on by the jesuits could be understood as one of the most important factors to explain the linguistic changes as well as the territorial and ethnic expansion the tupinamba language underwent in its historical drift in order to become a language of general and supra-ethnic purposes.