Reports of the National Center for Science Education

Review: Darwin’s Sacred Cause

Darwin’s Sacred Cause: How a Hatred of Slavery Shaped Darwin’s Views on Human Evolution
Adrian Desmond and James Moore
New York: Houghton Mifflin Harcourt, 2009. 448 pages
Reviewed by
John Waller

In 1991 Adrian Desmond and James Moore teamed up to write a wonderful book. Called simply Darwin (New York: Warner Books, 1991), this biography of Charles Darwin rightly won plaudits from fellow historians and a wider reading public, both camps awed by the authors’ depth of research, their fluency of expression, and their ability to bring the tumultuousness of Darwin’s England to life. A central theme informed Desmond and Moore’s account: the belief that Darwin was made sick, scared, and highly sensitive by the association of evolutionist thought and political radicalism. It was not a new argument but they explained it with tremendous brio. In addition, they presented natural selection as an idea born, in part, of the relentless competition and jostling for position which defined the new industrial order. Their clever, atmospheric, and enthralling biography put Darwin firmly back in his time and place without diminishing the reader’s appreciation for the great man’s qualities as a scientific thinker.

Eighteen years later Desmond and Moore have produced another striking book that will once more get historians talking and challenge staid stereotypes about how Darwin arrived at one of the most important realisations in modern science. Darwin’s Sacred Cause argues, in short, that Darwin developed his evolutionary theory not with the coolness of a scientist interested only in higher truths, but with a hatred for slavery so intense that he was hag-driven to prove that all human peoples were of one blood and ancestry. Proving that organisms can change over time, through natural and sexual selection, was part of a campaign, consciously and unconsciously waged, to bring an end to the evils against which his family had fought and from which he had recoiled on the Beagle voyage. Darwin might have obsessed about mockingbirds, fossil sloths, interbred pigeons, and overbreeding humans, but the "driving force" of his evolutionist thinking was the moral crime of slavery.

The result is fascinating and provocative. Written with much of Darwin’s flair and energy, Desmond and Moore tell an under-told story of how Darwin’s repugnance at slavery continued throughout his life, flaring up at times with all the emotional intensity of when he saw a female slave whipped in Argentina and an old lady’s collection of screws kept to crush the fingers of recalcitrant slaves. This book does the great service of humanising Charles Darwin. We see how keenly-fought debates over the nature of non-white peoples, their ultimate origins, even their capacity for interbreeding, occupied much of Darwin’s time and helped shape the reflections which led him to his mature theory. Along the way the reader receives a vivid, detailed, and utterly engaging lesson in the racial debates of Victorian Britain and America, with believers in a single origin for all humans as described in Genesis pitted against the often pro-slavery exponents of polygenesis, the idea that each race had been created separately. It is in the context of these conflicts, fought out in clubs and societies but with implications for plantations and slave markets, that Darwin formulated an evolutionary riposte to the polygenists. Or so Darwin’s Sacred Cause argues.

This stirring thesis raises many unanswered questions. If Darwin was so hell-bent on using science to undercut slavery, why not opt for a monogenist argument that all men and women were descended from Adam and Eve? Why bother bringing plants and animals into the picture at all? Moreover, the problem with making transmutation the basis for a critique of slavery was that it posed the question of how far back the splits among races had occurred. A few thousand years? A few million? Tens of millions? Since fossil hunters had yet to find a convincing human precursor, the branching among human races could theoretically be thrust back a very long way indeed. Inveterate racists could — and did — assert that the common ancestor of human races lived many millions of years ago, while the opponents of slavery opted for a more recent division. Evolutionary theory did not vouchsafe any one position. Nor does all the evidence as marshalled by Desmond and Moore neatly fit their hypothesis (as they at times concede). For if the brutality of slave-owning regimes put so much fire in Darwin’s belly, why did he write with cool indifference about the "inevitable" extinction of peoples like the Australian aboriginals? And why did he feel the need to insist that "savage" peoples were the moral and intellectual inferiors of whites?

One of the most remarkable features of this book is its originality. Desmond and Moore’s Darwin was far less bold in its analysis: historians had long pointed out that a fear of social ostracism contributed to Darwin’s delaying publication of his theory and even Karl Marx had recognised the clear affinities between the theory of natural selection and the often highly creative state of competition which fuels capitalist society. This time, however, Desmond and Moore are presenting a thesis which has been played in hushed tones, if at all, by previous Darwin scholars.

For this very reason their racy, rollicking style may not have been the most appropriate choice. A comparison to Darwin’s On the Origin of Species is germane. Knowing that his theory was going to be hotly contested and painfully aware of some important gaps in his data, Darwin presented his theory in the form of "one long argument", meticulously piecing together thousands of individual facts. In fact, the Origin has been compared aptly to a legal brief. So Darwin told the reader at every turn what he was arguing and how far his evidence went. He also did something unlike any attorney worth his fee: he devoted a chapter to acknowledging and then trying to argue around a set of thorny problems with this theory. Darwin’s great book was compelling because it is at once authoritative, brimming with data and candid about its limitations. Desmond and Moore’s Darwin’s Sacred Cause is also "one long argument", but it is written in the form of a breathless narrative replete with rhetorical flourishes. This makes it a superb and edifying read. But it also means that readers may find it hard to judge the quality of the evidence. There is no attempt to compare the relative importance of, say, slavery and mockingbirds, or Fuegians and finches. In fact, at one point we are reminded that "humans were not the sole source of insights into transmutation" (p 124). This would sound like outrageous understatement were it not for the fact that the preceding pages contain barely a mention of fossils or biogeography. Clearly Desmond and Moore know as much about the scientific basis of Darwin’s science as anyone alive. Nevertheless their style lacks the disarming clarity which left many of Darwin’s readers feeling that they were being told it as it is.

In sum, this is another splendid book from Desmond and Moore, the product of vast learning and deep sympathy, conveyed with often lyrical prose. If there are difficulties with the claims they make, they have at least provided, as Darwin said of his fledgling theory in 1837, a "theory by which to work." Time will tell if it has the strength to survive.

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