"The abolition of slavery and serfdom is to be attributed neither to the teachings of theologians and moralists nor to weakness or generosity on the part of the masters. There were among the teachers of religion and ethics as many eloquent defenders of bondage as opponents. Servile labor disappeared because it could not stand the competition of free labor; its unprofitability sealed its doom in the market economy."
January 1, 1970
https://en.wikiquote.org/wiki/Slavery