The objective of this article is to characterize the argumental strategy of Juan de Solorzano Pereira in one of the chapters of the Politica Indiana, by distinguishing the special features of his thought-structures and their goals. The methodology of this article is based on the Model-reader concept to characterize the adressee of Solorzanos's work and to discover the effect he sought. Likewise, the article envolves the premise that historical legal argumentation rules are a meaningful manifestation of the Spanish colonial legal culture. The main outcome of this article is the evidence of the political function of Solorzanos's legal argumentation.