[roughly]

I think that's how they justified it, but all the looting and slave labor are what required the justification.

The book "Why Nations Fail" spends a while discussing the Spanish approach to the Americas, and "Extractive" doesn't even begin to cover it.

[christkv]

You do realize that the Aztecs also practiced slavery as well.

[AlecSchueler]

That in no way justifies the behavior of the Spanish at the time.