Question

how did the spanish address de las cases`s criticisms of their brutal treatment of native american groups?

Answer 1

Wikipedia says that

In 1515, he reformed his views, gave up his Indian slaves and encomienda, ... instead of Natives in the West-Indian colonies; consequently, criticisms have .... In 1513, as a chaplain, Las Casas participated in Diego Velázquez de Cuéllar's and ..... Sometimes Indigenous nobility even visited Spain to relate their cases to him

Answer 2

Queen Isabella requiredQueen Isabella required the Conquistadors to read to Native populations a statement, warning them that if they did not comply, they would be punished severely. The statement had little effect because it was read to the Native people in Spanish, a language they did not know.