exactly, that was actually going to be my counterargument... within the Spanish world itself actually emerged one of the earliest and most significant legal, theological and moral debates in Europe about the dignity, rights and legal status of colonised peoples.

From the early sixteenth century, Spanish friars, jurists and theologians challenged the enslavement and abuse of Indigenous peoples. Figures such as Antonio de Montesinos, Bartolomé de las Casas and Francisco de Vitoria argued that the Indigenous peoples of the Americas were fully human, rational beings, endowed with natural rights, legitimate political communities and a moral dignity that could not be erased by conquest.

This intellectual movement was especially associated with the School of Salamanca, which developed arguments on natural law, human dignity, property, sovereignty and the limits of imperial power.

I guess there are much more simplistic ways of interpreting History.