De Indis (On the Indians)
1532
Summary
Francisco de Vitoria's landmark 1532 lecture at the University of Salamanca, laying the groundwork for international law and natural rights theory. Vitoria argued that the indigenous peoples of the Americas possessed true sovereignty and property rights under natural law, and that no political or religious authority — not even the Pope or the Emperor — could strip them of these rights. The work is a foundational text of the modern law of nations.