This excerpt comes from David Brion Davis’ Inhuman Bondage: The Rise and Fall of Slavery in the New World:
“For example, David Hume, Britain’s most respected philosopher in the twentieth century, wrote in 1748:
“I am apt to suspect the Negroes, and in general all other species of men, to be naturally inferior to the whites. There never was any civilized nation of any other complection (sic) 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 (from “Essays: Moral, Political, and Literary”)
And here is Voltaire, writing in 1756:
“Their round eyes, their flat nose, their lips which are always dark, their differently shaped ears, the wool on their head, the measure even of their intelligence establishes between them and other species of men prodigious differences (from “Essai sur les moeurs“).
And Immanuel Kant, writing in 1764:
“The Negroes of Africa have received from nature no intelligence that rises above the foolish. The difference between the two races is thus a substantial one: it appears to be just as great in respect to the faculties of the mind as in color …. Hike invites anyone to quote a single example of a Negro who has exhibited talents (from “Observations on the Feeling of the Beautiful and the Sublime”).
The relationship between the negro and the Enlightenment is complex: on the one hand, the doctrine of liberty and equality and universal human rights was extremely corrosive of racial hierarchies, as manifested in the French Revolution; on the other hand, scientific positivism or measuring things in pursuit of knowledge reinforced and elaborated racial hierarchies, as in Blumenbach’s racial taxonomy.