Darwin, Lincoln, and Slavery

At this time of the year, we celebrate the remarkable coincidence of Abraham Lincoln and Charles Darwin being born on the same day--February 12, 1809. Last year, I wrote a post on their intellectual similarities, which can be found here.

As I said then, there are at least five points of similarity between Darwin and Lincoln. (1) Both believed in a universe governed by natural causes. (2) Both were accused of denying the Biblical doctrine of Creation. (3) Both spoke of God as First Cause. (4) Both appealed to the Bible as a source of moral teaching, even as they also appealed to a natural moral sense independent of Biblical religion. (5) And both abhorred slavery as immoral.

From his voyage on the "Beagle," Darwin was horrified by the brutal treatment of slaves in South America, and this reinforced an abolitionist disposition that ran through his family.

Proslavery fanatics in the American South and elsewhere found support for slavery in the Bible and in science. The argument for scientific racism rested on the claim that the human races were actually separate species, and that the black species was naturally inferior to the white species. In March of 1861, Alexander Stephens, the new vice-president of the Confederate States of America, insisted that Thomas Jefferson's belief in natural equality had been refuted by modern science. "Our new government," he declared, "is founded upon exactly the opposite idea; its foundations are laid, its corner-stone rests upon the great truth, that the negro is not the equal to the white man; that slavery--subordination to the superior race--is his natural and normal condition."

Against this "polygenist" claim of the scientific racists that the human races were separate species, Darwin defended the "monogenist" position that the races are only varieties or sub-species of the same race. This meant that he had to explain the evolution of racial differences. And he tried to do this by developing his idea of "sexual selection": just as human plant and animal breeders can select for desirable traits, animals act as self-breeders in selecting mates. So the observable differences in the human races could be the product of aesthetic differences in human racial populations.

The importance that Darwin gave to sexual selection is indicated by the fact that over half of The Descent of Man is devoted to sexual selection. In the Introduction to the Penguin Classics edition of The Descent of Man, James Moore and Adrian Desmond argue that Darwin's primary motivation for writing the whole book was to attack slavery and racist science.

The Rev. John Brodie Innes--Darwin's vicar--saw this when he first read Darwin's book. He wrote to Darwin: "I hold to the old belief that a man was made a man though developed into niggers who must be made to work and better men able to make them, if those radicals did not interfere with the salutary chastisement needful, neglecting the lesson taught by the black ant slaves to the white." To which Darwin replied: "my views do not lead me to such conclusions about negroes & slavery as yours do: I consider myself a good way ahead of you, as far as this goes."

Innes' reference to ant slavery is revealing. In my chapter on slavery in Darwinian Natural Right, I argue that considering the similarities and differences between ant slavery and human slavery illuminates the biological nature of slavery. The similarities suggest that in both cases slavery arises as a natural form of social parasitism in which slavemakers exploit their slaves through coercion and manipulation. But the differences between ant slavery and human slavery suggest that human beings are naturally inclined to detect and resist exploitation through slavery.

Among human beings, the coercion of slaves by masters cannot be based on a natural complementarity of desires. The master's desire to exploit the slave clashes with the slave's desire to be free from exploitation.

Darwin and Lincoln saw this as showing that slavery is contrary to human nature and thus contrary to natural right.