Johnson on the Salamanca School

From Boswell's Life of Johnson:

1763
He this evening again recommended to me to perambulate Spain. I said it would amuse him to get a letter from me dated at Salamancha. JOHNSON. "I love the University of Salamancha; for when the Spaniards were in doubt as to the lawfulness of their conquering America, the University of Salamancha gave it as their opinion that it was not lawful." He spoke this with great emotion, and with that generous warmth which dictated the lines in his "London," against Spanish encroachment.

Here Dr. Johnson is referring to the writers such as Francisco de Vitoria, Domingo de Soto, etc. who argued against the American conquest. The Indians were sovereign and should not be forced to be under the Auhority of the Pope or the Spanish Crown. However, there was also no way for the Indians to completely bar the Spaniards from their land. Nor could the task of evangelization be prohibited.