The so-called Aristotelian defense of enslaving the americans, which Juan Ginés de Sepúlveda supposedly yielded in the 16th century, is, as I shall try to prove along this paper, a misunderstanding produced by careless and simplistic interpretations which do not consider the Sepulveda’s approach to Aristotle’s Politics, the Latin translation he published, the political and social context on Hispanic Monarchy during that century and some key concepts of Roman Law. Besides, the preconception, created by Menéndez Pelayo, maybe unintentionally, by translating a part of the title of the treatise Democrates alter, sive de iustis belli causis apud Indos, by “against the indians”, printed a serious brand on Sepúlveda like a slavery defender since 19th century. With this text, I want to show the reading and interpretation Sepúlveda made about Aristotelian work in the light of textual and contextual conditionings, which make clear the way the spaniard humanist deals with the philosophical and political question of indigenous conquest.