ETHICS This illustration to the Codex Azcatitla shows an Indian being baptized amid a throng of tonsured friars Confession of Princes Thus casuistry acquired political as well as ethical importance During the sixteenth century the casuists had to face a number of novel moral problems One of the most important was the relationship of Christians to the original inhabitants of the newly discovered continent of America Were the Spanish and Portuguese colonists entitled to annex the lands of the indigenous peoples and make them their slaves? The Emperor Charles V called a conference of theologians at Valladolid in 1550 to discuss the issue His imperial historiographer, Sepulveda, basing his theories on Aristotle’s teaching that some men were better Wtted to serve than to rule, and were therefore natural slaves, argued that American Indians, who lived a life of rudeness and inferiority, and were ignorant of Christianity, could justly be enslaved and forcibly converted This position was controverted on the spot by the missionary Bartolome de las Casas, and forcefully attacked in publications by two of the most inXuential Spanish theologians of the age, the Dominican Francisco de Vitoria and the Jesuit Franscisco Suarez 248