Perhaps the most celebrated collision between scientific rationality and antiracist sensibility came in a Tennessee courtroom in 1925 when the teacher John Scopes was prosecuted for propagating Darwin’s theory of evolution in the classroom. Leading the prosecution was America’s most famous anti-Darwinist William Jennings Bryan, whose campaigning had persuaded Tennessee to pass a law outlawing the teaching of Darwin’s theory.
Bryan is usually portrayed as an ignorant, Bible-thumping, reactionary buffoon. He was in fact a radical of national renown who three times ran as the Democratic presidential candidate (and three times lost). What shaped his opposition to Darwinism was not his religious literalism but his search for social justice. ‘Darwinian theory’, Bryan wrote, ‘represents man as reaching his present perfection by the operation of the law of hate – the merciless law by which the strong crowd out and kill off the weak.’ At a time when exploitation, oppression, war and genocide could all be justified in the name of the ‘survival of the fittest, there was, for someone like Bryan, no way of challenging social iniquities without confronting Darwinism itself.
It is this view of the relationship between Darwinism and social justice that Adrian Desmond and James Moore challenge in Darwin’s Sacred Cause. It was, they insist, the very search for social justice, and in particular the desire to overthrow the evil of slavery, that led Darwin to the theory of evolution in the first place. It is a highly distinctive account of Darwin’s intellectual development.
The conventional view is that over the space of nearly three decades Darwin meticulously pieced together an empirical jigsaw out of which emerged his vision of evolution by natural selection. The most explosive consequence of Darwin’s theory was its implication for humans. Yet the question of human origins gets barely a mention in The Origin of Species because, the traditional account suggests, Darwin was reluctant to enter such dangerous territory.
Desmond and Moore turn this account on its head. The question of humanity, they insist, was not peripheral but central to Darwin’s quest. ‘Human evolution wasn’t the last piece in the evolutionary jigsaw. It was the first.’ Darwin’s righteous anger about slavery – his ‘sacred cause’ – instilled in him a deep moral belief in human unity that shaped his entire view of creation. ‘I cannot help thinking’ Darwin wrote in his notebook in 1838, ‘good analogy might be traced between relationship of all men now living & the classification of animals’. Darwin’s heresy, Desmond and Moore observe, was not to apply to humans ideas about the origins of non-human species, but on the contrary, ‘to extend human racial relationships to all the branches of creation’.
In reposing Darwin’s argument in this fashion, Desmond and Moore also take a pot-shot at the imageof Darwin as a disinterested scholar driven simply by a ‘zeal for scientific knowledge’. ‘Rather than seeing “the facts” force evolution on Darwin’, they write, ‘we find a moral passion firing his evolutionary work’.
Britain had abolished the slave trade in 1807, two years before Darwin’s birth. But slavery was still flourishing both in the colonies and in America. For Dissenting families such the Darwins and the Wedgwoods (one of whom, his cousin Emma, Darwin was to marry) there were few causes that more stoked their moral passions. And at the heart of their opposition was the belief that the ‘Universal Father [had] made of one blood all nations’.
Not only was slavery thriving but racial attitudes were hardening. The Enlightenment belief that racial differences were plastic and that social progress would overcome racial inequalities was giving way to the idea such inequalities were deep-set and ineradicable. Influential voices were making the case for ‘polygenism’: the claim that human races belonged not to a single stock but were distinct species with separate origins. At the forefront of promoting polygenism was the ‘American School’ of anthropologists, led by Samuel Morton, Josiah Clark Nott and George Gliddon with considerable assistance from the Swiss-born naturalist Louis Agassiz, probably the most celebrated scientist of the mid-nineteenth century.
It was against this background that Darwin developed his evolutionary ideas. The moral education provided by his family was buttressed by his experiences during the voyage of the Beagle. ‘Never in the five years’, Desmond and Moore write, ‘had he been able to escape slavery, now seen for what it was, a global empire of evil requiring a global remedy’. It was the treatment of slaves in Brazil as much as the diversity of finches’ beaks on the Galapagos Islands that drove him to think about the relationship between the unity of life and its diversity. Back home, Darwin became increasingly drawn into the debate about racial origins and polygenism raised by the American School, and was driven particularly by his desire to demolish Agassiz’s vision of distinct primordial centres of racial creation.
Luminously written and intensively researched, Darwin’s Sacred Cause makes a strong case for the importance of anti-slavery not just to Darwin’s moral temper but also to his scientific work. Desmond and Moore retread much of the ground of their seminal 1991 biography of Darwin, yet every page feels fresh and exciting, and will undoubtedly make us rethink not just Darwin’s intellectual journey but also the nineteenth century relationship between race and science.
Nevertheless the claim that it was ‘Darwin’s abhorrence of slavery [that] led to our modern understanding of evolution’ seems to stretch the argument too far. The book struggles to explain, for instance, why if the ‘sacred cause’ was so all-important, Darwin decided not to talk about humans in The Origin of Species.
Central to Desmond and Moore’s argument is claim that polygenism was closely related to the desire to defend slavery. Many polygenists opposed abolition. Many Southerners, however, including Southern slave-owners, opposed polygenism. In 1854 the fire-and-brimstone pro-slavery Richmond Inquirer declared that the ‘doctrine of diversity’ might provide an excellent defence of slavery, but Southerners could not afford such a defence if the Bible was ‘the price it must pay for them.’ As the historian William Stanton has observed, ‘when the issue was clearly drawn, the South turned its back on the only intellectually respectable defense of slavery it could have taken up.’
As a biological theory, nineteenth century racial thought was shaped less by the attempts of a reactionary slave owning class to justify their privileges than by the growing pessimism among liberals about the possibilities of equality and social progress. Hence the arguments of the American school, paradoxically, appealed more to Northern liberals than they did to Southern conservatives.
Towards the end of their book, Desmond and Moore discuss Darwin’s theory of sexual selection, which he laid out a length in his 1871 work Descent of Man. Darwin suggested that in both humans and other animals, one or other of the sexes often takes a liking to a particular look and preferentially mate with individuals sporting that trait. This was how, Darwin thought, physical differences between races, such as skin colour or hair texture, had became defined.
Sexual selection, Desmond and Moore suggest, provided a mechanism by which Darwin could explain the origins of racial differences without giving up on the idea of human unity. But Darwin’s argument was less clearcut. He believed that sexual selection ensured that racial traits arose very early in human history, were not adaptive and were relatively fixed. He also believed that natural selection continued to operate on humans, making the different races morally and intellectually distinct and continually in conflict. ‘When two races of men meet’, Darwin wrote in his notebook, ‘they act precisely like two species of animals’ in that ‘they fight, eat each other, bring diseases to each other, etc, but then comes the more deadly struggle, namely which have the best fitted organisation or instinct (ie intellect in man) to gain the day?’ Staunch in his opposition to slavery and fierce in his defence of human unity, Darwin could nevertheless believe not just in a racial hierarchy, but also in the idea that races behaved as if they were species.
None of this should detract, however, from the value of Desmond and Moore’s work. It is an important attempt to transform our understanding of the very landscape of Darwin’s thought. In a year in the which we will be inundated with Darwin books, Darwin’s Sacred Cause is certain to be one of the most significant.