Descartes' Bones (26 page)

The revolution left a confusing political situation that from the point of view of traditionalists was only exacerbated by the growing acceptance of science and materialism. By midcentury German scientists were openly proclaiming atheism as a creed. Beginning in 1854, the situation led to a showdown between two renowned German scientists—physiologist Rudolf Wagner and zoologist Karl Vogt—who engaged in a public debate on whether the growing mountain of scientific data from all fronts contradicted biblical accounts of the origin of life. Wagner came down firmly on the conservative side: he believed that every scientific fact would be found to be in accord with the story of creation; he further argued that religion and religious morality were the foundations of society and that science had a duty to keep its investigations within the boundaries that Christian teaching allowed. Science, he warned his colleagues, “would be suspected of destroying the moral foundations of social order” if it developed a materialistic philosophy. Wagner identified the root of materialism in brain science, and he went so far as to claim that scientists in Germany had a patriotic duty “to the nation” to keep mind and brain apart. Vogt, a defiant materialist, ridiculed such ideas, declared it obvious that the brain was the organ of thought, and set out the equation of mind and brain in a particularly graphic analogy: “The brain secretes thoughts, as the stomach secretes gastric juice, the liver bile, and the kidneys urine.” Later, Vogt took apart the Cartesian notion that equated nonmaterial soul and mind. “The activities of the soul are only functions of the brain,” he asserted. “There is no independent soul.”

Wagner found this sort of thinking dangerous nonsense yet, curiously enough, he reacted to it by devoting the last part of his career to a study of the doctrine of cranial capacity. His plan was to debunk materialism by taking on one of its most elemental notions. Surely if it was true that there was a firm link between the physical brain and seemingly nonmaterial thoughts, size would have to matter—that is, if the brain was the mind, then a bigger mind would necessitate a bigger brain. Therefore, he would do the most thorough study yet of the brains and skulls of eminent thinkers and compare them with those of normal people.

Wagner began his study in a fairly creepy way. As chance would have it, he had made his decision to examine great brains as Carl Friedrich Gauss, one of the greatest mathematicians of all time and one of Wagner's colleagues at the University of Göttingen, lay dying. The two men did not know each other well, but suddenly Wagner became a constant presence at Gauss's bedside. After his death, the family agreed to have his body examined for scientific purposes. Wagner got the brain.

Wagner went on to collect brains and skulls of other notables (a clutch of elderly thinkers at Göttingen died at around the same time, and Wagner managed to snag all of their heads), along with those of ordinary mortals, murderers, rapists, and the mentally ill, and wrote a study comparing weights and features. Wagner was forced to admit that the brains of geniuses seemed to have more convolutions on the surface, but he believed his tabulation of brains and their weights proved that size did not, in fact, matter. Of 964 brains, Gauss's, at 1,492 grams, came in in 125th place. Among those at the top of the list were brains that had belonged to an ordinary worker and “an imbecile.”

The details of Wagner's study of brain weights reached Paris in February 1861 and instantly became the main topic of discussion for Pierre-Paul Broca's Anthropology Society. Broca himself had pioneered techniques for measuring skulls and brains and had become a believer in the correlation between brain size and intelligence. Far from being dissuaded by Wagner's paper, Broca found it close to proof of the theory. “Among the questions that have been put into discussion up to now in the Anthropology Society, none is equal in interest or importance to the current one,” he told his colleagues. He went on to demonstrate that for him cranial capacity not only bore on the materialism debate but was tied to the effort to establish a hierarchy of races. “The great importance of craniology has struck anthropologists so much that many have neglected other parts of our science in order to devote ourselves exclusively to the study of skulls,” he said. “This preference is without doubt legitimate, but it would not be if the examination of the bones of the head had only a purely anatomical significance and if one did not hope to find there some data relative to the intellectual value of the various human races.”

Beginning in March 1861 and continuing for some months, Broca laid before his colleagues the evidence that both Wagner and he himself had amassed. To begin with, Broca acknowledged the unprecedented work that Wagner had done and the value that lay in it, but he found that Wagner's conclusions were entirely untrustworthy, owing to a methodological error. “Monsieur Wagner brought together pell-mell very disparate observations,” Broca noted. “He enumerated, by weight, the brains of both sexes and all ages, the brains of idiots, epileptics, and the insane, hydroce-phalics[those with ‘water on the brain'], apoplectics, paralytics with or without madness; it surprises me that he confounded so many miscellaneous elements.”

It was well known that women's brains tended to be smaller than men's and, of course, that children's were smaller than adults'; many of the ailments Broca cited had also been shown to result in either dramatically smaller or larger brains. Broca thus attempted to refocus Wagner's data by analyzing only what he believed to be the brains of healthy adult males. The new calculation brought the number down from 964 to 347. Also following Wagner, Broca supplemented the database by combing the historical record, some evidence of which he admitted was circumstantial. An account of the life of Pascal noted that after the death of the philosopher an autopsy was performed and the doctors observed that “there was a prodigious wealth of brain matter.” An account from the autopsy of Oliver Cromwell reported that, according to Broca, “the brain of the Protector weighed no less than six and one-quarter pounds.” Broca dismissed this figure as preposterously greater than that of any known brain, but he pointed out that in old English measurement there were only twelve ounces in a pound, so recalculating on that basis gave what was for Broca a truly massive yet just believable weight for the brain of the man who had launched the English civil war. Moving to another area of genius, Broca informed his colleagues that the brain of Lord Byron had weighed 1,807 grams, 400 grams more than that of the average adult male.

And what about French geniuses? Some very fine evidence, Broca asserted, lay virtually at their fingertips: the remains of the great Cuvier himself. “All the distinguished anatomists who assisted at the autopsy of Cuvier declared that they had never seen a brain so covered in convolutions so complicated and deep,” he declared. Happily, those scientists had removed Cuvier's brain and weighed it, and Broca was pleased to report that the result—1,830 grams—put Cuvier at the very top of the list. In short, Broca's analysis of Wagner's tabulation—augmented and corrected by Broca himself—yielded compelling evidence of a connection between head size and intelligence. Broca summarized his conclusions succinctly: “In general, the brain is larger in men than in women, in eminent men than in men of mediocre talent, in superior races than in inferior races. Other things being equal, there is a remarkable relationship between the development of intelligence and the volume of the brain.”

Cuvier himself would perhaps have had mixed feelings. On the one hand, being used postmortem as part of a rigorous scientific study would no doubt have pleased him. But he would not have gone along with Broca's materialist thesis—much less with being used in an effort to prove it.

Neither, as it happened, did one of Broca's esteemed colleagues at the Anthropology Society care for Broca's argument. Louis-Pierre Gratiolet was Broca's equal as a scientist and anatomist. He was the first to recognize that the two hemispheres of the brain each direct the movement of the opposite side of the body; Gratiolet also identified the four lobes of the brain and gave them their names (occipital, temporal, parietal, and frontal), as well as the insula, a central region that is sometimes considered a fifth lobe. Gratiolet happened to come from the same small town as Pierre-Paul Broca (there is today a place Broca and a boulevard Gratiolet in the town of Sainte-Foy-La-Grande), so that the two men had known each other most of their lives. But Gratiolet had had a hard time of it. He had been raised with expectations of social position, but the family was always poor and despite education and achievements he had never managed the trick of getting proper social standing, so that he stayed poor his whole life. Where Broca was fiery and defiant, Gratiolet was quiet but indefatigable. Broca commanded attention; Gratiolet, with his hunted, brooding aspect, tended to go unnoticed.

But Gratiolet knew the brain as well as anyone alive (as was apparent in the detail, not to mention the title, of his magnum opus,
The Cerebral Folds of Man and the Primates
), and as he pored over Wagner's work he found himself unconvinced by Broca's recalibration of it, unable to make a connection between brain weight or skull size and intelligence. If Wagner had erred—perhaps intentionally fudging results by grouping disparate types of brains together in his table—it seemed to Gratiolet that Broca had also pushed and pulled the data to fit his theory. Since Broca put such emphasis on Cuvier's brain, Gratiolet delved into the Museum of Natural History in search of it, only to discover that the brain had not been preserved. Further, the skull was now missing.

Gratiolet came to the meeting of June 6 armed with this and other information. He took his colleagues carefully through Wagner's figures. Gauss was probably the greatest genius of the era, but the data, Gratiolet concluded, was clear: “This is not an enormous brain; this is not an exceptional weight.” He took another example from Wagner's Göttingen brains: Johann Hausmann, a mineralogist. Seeing that his brain did not rank high on Wagner's list, Broca had demoted the man to a lower order of intelligence, but this didn't seem fair either to the data or to Hausmann. Germans who knew his work acknowledged that Hausmann was a scientist of great distinction, and French colleagues said so as well. “One can thus affirm without presumption that this was no vulgar mind,” Gratiolet observed. “However, and I repeat: his brain is small.”

Now it was time to get closer to home: Gratiolet challenged Broca on the size of Cuvier's brain. “If it is permitted to take [Broca's] expressions literally, the weight of Cuvier's brain is, if not monstrous, hardly less than supernatural,” he began. However, there was no way to verify—or for that matter to disprove—the figure of 1,830 grams. But Gratiolet, in his dogged way, had pursued a novel idea. Weighing brains might not be a common practice, it occurred to him, but measuring heads was. And who measures heads but a hatter? He had consulted among former friends of Cuvier and, lo, he found one, a doctor by the name of Rousseau, who had in his possession a hat that had belonged to the former permanent secretary of the academy. Gratiolet took this item to one of the most renowned hatters in Paris, who told him that its size was at the large end of the scale but by no means excessive. But Gratiolet had more to add. “Cuvier,” he told his colleagues, “had an extremely abundant mass of hair” that was furthermore quite bushy. Thus the dimensions of the hat were actually greater than the size of the skull it sat upon. “The measurements that I have just pointed out seem to prove rather obviously that if the skull of Cuvier had a considerable size, this size is not absolutely exceptional and unique.”

But Gratiolet's presentation—his attempt to deconstruct the cranial capacity theory—had another chapter to it. Following the logic of the cranial capacity argument, a great intellect meant a large brain and skull, and a supreme intellect implied a supersized brain and skull. Gauss, a man of titanic mental achievement, had a brain of rather average size. Well and good: that was one example to counter the argument. Could the brain or skull of another genius of similar, or even greater, stature be found? Gratiolet knew the museum's collection well, and he produced just the item. If those favoring the cranial capacity theory had been discomfited by the example of Gauss, and somewhat mollified by that of Cuvier, what would they say to the head of René Descartes? Descartes had long since come to be regarded as not only the father of modernity but the intellectual father of the French nation. From his mind—from his
brain,
Broca and his cohorts would have insisted—had come the framework for approaching two centuries' worth of solutions or speculative solutions to particular riddles about the beating of the heart, the colors of the rainbow, and the setting of the sun—and indeed the nature of the mind. And yet, as had been immediately apparent to everyone who had handled it over the past 190 years, Descartes' cranium was a small and rather delicate object. The Latin poem written on its crown stated it plainly.
Parvula calvaria
: small skull.

“We possess in the Museum a skull that appears to be that of Descartes,” Gratiolet began. “This skull, religiously preserved in Sweden in a circle of Cartesians, and covered with inscriptions that attest to its origins, eventually passed into more ignorant hands, so much so that one day it was sold for a vile sum in a public auction. Berzelius, who, by good fortune, assisted at the bidding, bought this precious relic and hastened to return it to France.” Gratiolet had gotten a few details of the skull's wanderings wrong, but his main point was that the skull was in the museum's possession. It had been compared with a likeness of Descartes, he said, and the inscriptions on it had been checked. The academy itself had done the detective work, and had come away convinced as to its authenticity. “And yet, this skull, rather than being remarkably large, as it must be if genius depended on the volume of the brain, is,
au contraire,
quite small,” Gratiolet said. But there was something else, which Gratiolet found compelling. This skull, he noted, “is admirably shaped.” In fact, he went on, “This is one of the most beautiful types of Caucasian skull that it is possible to see, and, to summarize, I would say that it is the form and not the volume that gives the brain its dignity.”