“To have a correct view of the rules adopted and applied to Indian affairs when grants were issued by the kings of England for lands in North America,” Haywood wrote, “we must look to the prevailing opinions in those days in matters of religion. The spiritual fathers of Christendom [the popes] dictated the creed of the people, and assumed enormous powers. …”
The pope’s “grants of infidel countries were considered binding in heaven, and of course upon the consciences of Christians,” wrote Haywood. What was the thinking behind such grants? Haywood pointed to Calvin’s Case (1608), in which Lord Edward Coke held that “all infidels are in law ‘perpetual enemies’; for between them, as with the devils [sic] whose subjects they be, and the Christian, there is perpetual hostility.”
At the time of Calvin’s Case, said Haywood, the “old law of nations” had not been “superseded by the modern [law of nations], so far as regarded their conduct toward infidel countries.” He continued: “The same view and practices had been exhibited by all the nations of antiquity; the Babylonians, the Persians, Greeks, and Romans, and by the Israelites under the Guidance of Moses and Joshua. According to what it [the law of nations] permitted, they extirpated [uprooted] the inhabitants of the countries they invaded, driving them from their habitations, or killing and enslaving them, as best suited their present circumstances.”
The "nations of antiquity" also had laws sanctioning the divine right of kings, slavery and serfdom, and women as chattel. Should the US uphold these old laws because they were valid once? I don't think so.
Many conservatives today are up in arms because US judges occasionally cite examples (not precedents) in international law. If these conservatives were consistent, they'd denounce the US court decisions based on the papal Doctrine of Discovery. They'd argue for overturning these decisions and upholding tribal sovereignty.
Instead, they're likely to claim these court decisions go too far. That tribal sovereignty is a fiction and tribes are subject to federal and state control. So much for the intellectual integrity of conservatives.
For more on the subject, see Episcopal Church Repudiates Doctrine of Discovery and Those Evil Europeans.