'Democrates Alter, Or, on the Just Causes for War Against the Indians' by Juan Ginés De Sepulveda
Written in 1547 to justify the Spanish conquest of the Americas.
"...the Spanish have a perfect right to rule these barbarians of the New World, who in humanity are as inferior to the Spanish as children are to adults, or women are to men, for there exists between the two as great a difference as, I might even say, between apes and men.
Compare, then, these gifts with those possessed by these half-men, in whom you will barely find the vestiges of humanity, who not only do not possess any learning at all, but are not even literate, and eat human flesh?
Therefore, if you wish to reduce them, I do not say to our domination, but to a servitude a little less harsh, it will not be difficult for them to change their masters."