In the middle of the sixteenth century, and for the first time in history, an empire thoroughly questions where its own rights end, those of the winner, and where the rights of others begin, those of the loser. Bartolomé de las Casas and Ginés de Sepúlveda defend two historically antagonistic positions and debate on the natural rights of Native Americans. Almost 500 years later, a small group of experts analyzes what is considered the first debate in History on Human Rights.