Keywords: Arcos; Just War Theory; Spanish Colonization of the Americas; Vitoria; Sepúlveda.
The essay focuses on the almost forgotten Dominican Miguel de Arcos, a 16th Century central figure in the debate about the Spanish Conquest of the New World. The analysis of some of his documents, collected in the Universidad de Sevilla's "Fondo Antiguo", helps to reconstruct Arcos' contribution to the debate. The first part of the essay points out Arcos' relation with Juan Ginés de Sepúlveda and Francisco de Vitoria. The second and main part analyses the document "Parecer mío sobre un tratado de la guerra que se puede hacer a los indios", that is a brief comment written by Arcos on a lost work attributed to Vasco de Quiroga. Arcos' thought can also be better understood thanks to his inedit Suma of Quiroga's work. Finally, the analysis presents the influence of the Vitorian relectio De Indis on Arcos' considerations on Just War.