In his "Relación de Texcoco," Juan Bautista de Pomar (c. 1535-90) takes a political and moral stance against Spanish colonialism in Texcoco and the entire viceroyalty of New Spain. Responding to the "Instrucción y memoria's" (1577) request for information about the history and cultural practices of local populations, Pomar narrates the history of preconquest Texcocoan civilization as a civilized proto-Christian society, with monotheistic rulers and a virtuous community. In doing so, he enters into the polemic about indigenous rights and contests anti-indigenous discourses that justified conquest and colonialism in the sixteenth century. In particular, Pomar attacks the argument that indigenous populations could be enslaved because of their lack of natural reason. This article analyzes Pomar's manipulation of Christian discourses, which relocates the Spanish conception of morality in a preconquest indigenous context and enables his criticism of colonial policies of forced labor.