“I am apt to suspect the negroes and in general all the other species of men (for there are four or five different kinds) to be naturally inferior to the whites,” Enlightenment philosopher David Hume wrote in 1753. “There never was a civilized nation of any other complexion than white…. Such a uniform and constant difference could not happen, in so many countries and ages, if nature had not made an original distinction between these breeds of men.”