The people who founded 'modern' (15th-19th century) slavery were all Christians–starting with the Portuguese, and soon involving the Spanish, Dutch, French, and British, and later others.
@DavidSalo @LiberalLibrarian The Church, as you may know, gave the conquerors a rubric: they could enslave peoples who had heard the Gospel but were not Christians (i.e., Africans), but they could not enslave nations that had never had a chance to hear the Gospel (i.e., Indians). Pretty often they enslaved Indians anyway, but that was the rule.
Christianity actually went from "love your neighbor" to "here's how to tell which of your neighbors you may enslave" in about 1500 years.
@LiberalLibrarian @ImagineThat
In the year 311, it was a common opinion (if not exactly Church dogma) that Christians were forbidden from engaging in violence, particularly the state-sponsored violence of war.
In the year 312, Constantine defeated Maxentius at the Milvian Bridge and became Emperor of the Western Empire.
In the year 313, he and Licinius promulgated the Edict of Milan, making Christianity a permitted (and protected) religion in the Empire.
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@LiberalLibrarian @ImagineThat
In the year 314, at the Council of Arles, the Western Church determined that Christians were obliged to fight for the state and that the power of the state could be used to persecute 'heretics' (i.e., Christians who disagreed with the Church).
So the whole transformation from 'violence and persecution is bad!' to 'violence and persecution is good!' took about 3 years and was entirely based on political expediency.
@LiberalLibrarian @DavidSalo Only as quickly as they could.
One could argue that "enslave these, not those" is a step up from "Kill them all, God will know his own."
@ImagineThat @DavidSalo Christians went from victims of state violence to wielders of state violence far more quickly.