Now read this excerpt from the OER Project:
The Enlightenment had economic, ethical, and religious aspects, too. In the 1690s, Locke was a shareholder in the Royal African Company, which was profiting from the enslavement of Africans. He argued that slavery was okay if it resulted from “just war” (meaning the war was justified). After all, he believed firmly in the right to private property, and enslaved people were considered property.
But Locke rejected the idea that there were any intrinsic differences between humans from different places, with different religious beliefs or skin tones. Over the course of the eighteenth century, most Enlightenment thinkers took Locke’s lead and emphasized a sense of shared humanity.
Yet African enslavement kept growing. Profits from this trade contributed to the growth of European port cities and new industrial centers. Enlightenment thinkers increasingly struggled with the fact that the apparent “progress” of the world around them depended on the horrible violence of slavery.
Locke’s hypocritical position—of expressing one thing, but profiting economically from the opposite—became harder to maintain.
Religious groups like the Quakers, and philosophes like Jean-Jacques Rousseau and Adam Smith, called for the abolition of slavery. “From whatever aspect we regard the question,” wrote Rousseau, “the right of slavery is null and void...The words slave and right contradict each other..."