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CHAPTER 1
JEAN-BAPTISTE LAMARCK
BIOLOGICAL VISIONARY
RICHARD W. BURKHARDT JR.
In his capacity as "perpetual secretary" of the Academy of Sciences in Paris for nearly three decades, the distinguished comparative anatomist Georges Cuvier prepared the eulogies of thirty-nine different scientists. The very last was of the zoologist Jean-Baptiste Lamarck, Cuvier's former colleague at both the Academy of Sciences and the Museum of Natural History in Paris. As it happened, Cuvier died before he could deliver his éloge of Lamarck to the academy, but the piece was later read in his stead and published. It caused a stir because Cuvier had chosen to single out Lamarck's career as an object lesson in how science should not be done. Cuvier's obituary of Lamarck stands today as one of the cruelest scientific "eulogies" ever written.
Cuvier readily acknowledged that Lamarck had made important contributions to science through his work on animal and plant classification. What Cuvier could not abide was Lamarck's penchant, as Cuvier represented it, for building grand, explanatory edifices on wholly imaginary bases. These edifices, Cuvier said, were like the enchanted castles one reads about in old novels — they vanished in thin air as soon as the magic talismans on which they depended were broken. Maintaining that it would be a benefit to science if, instead of simply commenting on Lamarck's positive contributions to science, he also examined the ways in which Lamarck had strayed from science's true path, Cuvier offered a reconstruction of the "genealogy" of Lamarck's misguided theories, showing how Lamarck's system-building zeal was manifested in his quixotic efforts to overthrow the chemistry of Lavoisier, his various meteorological and geological ideas, and his theory of the origin and successive development of life in all its many forms. Of this last theory Cuvier wrote that such a theory might amuse a poet or stimulate more system-building by a metaphysician, "but it could not sustain for a moment the examination of anyone who has dissected a hand, an internal organ, or merely a feather."
In dismissing Lamarck's theory of organic evolution (and the idea of species mutability in general), Cuvier left himself, at least in this particular regard, on the wrong side of history. This is particularly ironic, given that Cuvier was the leading zoologist of the first third of the century. He transformed zoological classification with his comparative studies of animal organ systems. His pathbreaking work in vertebrate paleontology focused attention on the history of life on earth in a way that was unprecedented. The case can indeed be made that Cuvier's contributions to zoology and vertebrate paleontology ultimately helped make an evolutionary interpretation of life more plausible, notwithstanding his own ardent rejection of the idea of species change. But our primary goal here is not to contrast Lamarck's and Cuvier's respective contributions to biology. Our aim instead is to consider Lamarck's own style of thinking and how it helped him produce a broad, bold, novel vision of how the different forms of life came into existence. Half a century before Darwin, Lamarck maintained that nature had begun with the very simplest forms of life and then from these had successively developed, over time, all the others, from the tiniest monad all the way up to human beings. It was a vision well suited to a man who identified himself not just as a naturalist but as a naturalist-philosopher, and it was of profound importance for biology.
Born in 1744, Lamarck as a young man had wanted to be a soldier, but an injury during the Seven Year's War ended his military career. He proceeded to Paris, where he eventually made a name for himself as a botanist. The Comte de Buffon provided him an affiliation with the King's Garden (Jardin du Roi). In 1793, at the height of the French Revolution, and when Lamarck was nearly forty-nine years old, the King's Garden was reconstituted as the National Museum of Natural History. The transformation of the institution transformed Lamarck's career as well. He was appointed professor of the "insects, worms, and microscopic animals" — the group of animals we now call the invertebrates, thanks to Lamarck himself. He readily embraced the two primary responsibilities of his new position: teaching an annual course on the invertebrates and bringing order to the museum's invertebrate collection. He also served the museum ably in a series of administrative capacities, thereby demonstrating that he was no idle dreamer when it came to performing the institutional tasks required of him.
Had Lamarck remained a botanist, he most likely would never have come to believe in organic mutability, but taking on the new professorship opened new horizons for him. Identifying, ordering, and attempting to make sense of the remarkable array of different invertebrate forms was one part of it. Having to teach students about these animals and explain to students the importance of invertebrate zoology was another. Years later he recounted that when he was first given the job he felt he had been put in charge of the less interesting part of zoology: "It in effect seemed to me that there was more advantage and greater interest to be stimulated in the demonstration of the characters, ways of life, and habits of the lion than those of the earthworm." What Lamarck concluded not long after he began teaching was that the study of the invertebrates afforded insights that were truly profound. He was impressed by the way invertebrates manifested the intimate relationship between animal faculties and animal organization. He furthermore concluded that the way the invertebrate classes could be arranged in a series of increasing complexity corresponded to the actual course nature had taken in bringing all the different forms of life into existence.
The turn of the century was an immensely fertile period of Lamarck's career as a biologist, a period of breakthrough biological dreaming on his part, with a bold theory of organic change as the primary product. It bears underscoring that Lamarck initially made his new ideas on organic mutability known by presenting them to his students, not to his colleagues. He offered the earliest glimpses of his new thinking in the lecture that introduced his course on invertebrate zoology at the museum in 1800. He presented the first broad overview of his general explanation of organic diversity in his opening lecture of 1802. In his introductory lecture of 1803, he zeroed in on the species question. His students (a highly diverse lot in terms of their age, provenance, and career intentions) were signing up for his course in these years in appreciable numbers (132 in 1802, 71 in 1803). Knowing they would be struck by the novelty and singularity of his new views, he asked them to suspend their judgment until they had the chance to consider carefully these views and all the facts related to them. "It is on you yourselves," he urged, "that I call to pronounce on this great subject, when you have sufficiently examined and followed all the facts that bear on it."
Lamarck's invitation to his students represented the flip side of how he anticipated his colleagues would treat the same ideas. He had already seen his colleagues at the Academy of Sciences turn a cold shoulder to the chemical and meteorological memoirs he presented to them. He concluded they were too invested in their own ideas and reputations to greet new ideas with an open mind.
It may give us some appreciation for Lamarck's dissonant feelings in this period if we consider his two primary professional activities on the day he first offered a broad overview of his theory of organic change. The day was the seventeenth of May 1802 (the twenty-seventh of floréal, year ten, by the Republican calendar). Lamarck's course on invertebrate zoology was to meet for the first time that year, at half past noon. The lecture he gave on this occasion stands in retrospect as a milestone in the history of biology. Later that evening Lamarck met with his fellow professors/administrators for the museum's weekly administrative assembly. There he reported on the latest developments at the museum's menagerie, which he had been charged with overseeing since the previous July. His chief announcement was the happy news that the museum's female elephant had completely recovered from the worrisome digestive problems that had been ailing her. Ironically, while we know that Lamarck's colleagues greeted this news with satisfaction (and elected to send a letter of thanks to the veterinarian who helped cure the elephant), we know nothing about how Lamarck's students responded to the remarkable lecture he gave them earlier in the day. Also ironic is that Lamarck most likely said nothing to his fellow professors about what he had told his students earlier in the day. The weekly assemblies were devoted to handling the museum's business, not discussing scientific theory, and Lamarck in any case would not have expected his colleagues to welcome a new theory from him.
Lamarck was keen, nonetheless, that the new views he had presented to his students not be misrepresented. He decided he should get his lecture into print quickly and that he should accompany it with additional comments so that he would be better understood. Before he knew it (as he later explained), he had a small book on his hands without ever having intended to write it. A mere two months after delivering the opening lecture of his course, he presented the museum with a copy of his new book, Researches on the Organization of Living Bodies. In addition to the original lecture, the book included a long second section on what he called "direct generation" (i.e., "spontaneous generation") and the effects of moving fluids on living bodies, plus "some considerations relative to man," an "appendix" on the meaning of the word species, and a section entitled, "Researches on the Nervous Fluid: Preliminary Considerations."
Clearly Lamarck was not someone who deliberated for long before letting his ideas be known. That said, his Recherches of 1802 do not represent the whole sweep of his intellectual ambitions at the time. He had hoped to lay the groundwork for a new science he was naming "biologie," conceived as but one part of a three-part "terrestrial physics" also involving meteorology and "hydrogeology." His Hydrogéologie had already appeared, but he was putting his "biologie" aside, he explained, because of his other scientific responsibilities and his increasing ill health. A month later he used the excuse of ill health again when he asked the museum to relieve him of the responsibility of overseeing the menagerie.
Over the next decade and a half, poor health notwithstanding, Lamarck elaborated more fully his understanding of how the diversity of life arose. He did so most notably in his Zoological Philosophy of 1809 and in the 1815 introduction to his Natural History of the Invertebrates. The subtitle of his Zoological Philosophy is additional evidence of the breadth of his explanatory goals. He was offering Considerations relative to the natural history of animals; to the diversity of their organization and the faculties they derive from it; to the physical causes that maintain life in them and give rise to the movements they execute; finally, to those [physical causes] that produce sensation in some [animals] and intelligence in those that are endowed with it.
Here we confine our attention to the basic elements of Lamarck's thoughts on organic mutability. The first glimpse Lamarck provided of his new thinking, in 1800, was his conclusion that the standard view of the relation between animal structures and animal habits needed to be turned on his head. Habits, he said, were responsible for the form of the body and its parts, not the other way around. The webbed feet of ducks and geese, the curved claws of perching birds, the long legs and necks of shore birds — all these, he explained, were not there because the species had been originally created that way but were instead the consequence of long-maintained habits. By Lamarck's account, changes in environmental circumstances induced animals to adopt new habits. These new habits led over time to changes in structure and the acquisition of new faculties, "and little by little nature has arrived at the state where we see her now."
In the broader picture Lamarck set forth in 1802, the environmental influence on habits and structures took second place to the general tendency to increased complexity. He saw the process beginning with the "direct generation" from nonliving matter of the very simplest forms of life. These forms became increasingly complex as the result of the physical action of subtle fluids (primarily caloric [heat] and electricity) coursing through them. Subtle fluids and then ponderable fluids, carving out channels and organs in living forms, constituted the basic cause of the increasing complexity displayed in the general series of animal classes. Departures from the general series were the result of the influence of diverse environments. Environmental constraints were the reason why species, unlike the general "masses" of organization represented by the animal classes, could not be aligned in a single chain of being. The species formed "lateral ramifications" around the masses. As Lamarck explained, all that nature had required in bringing all the different forms of life into existence were "direct generation," the constructive action of fluids in motion, an infinite number of diverse and favorable circumstances, and an immensity of time.
Subsequently, in 1809, and again in 1815, Lamarck continued to present a theory of organic change featuring two different factors. In his Zoological Philosophy he wrote, "The state in which we now see all the animals is, on the one hand, the product of the increasing composition of organization, which tends to form a regular gradation, and, on the other hand, that of the influences of a multitude of very different circumstances that continually tend to destroy the regularity in the gradation of the increasing composition of organization."
Lamarck's two-part theory was in essence his explanation of why the diverse forms of life exhibited the broad pattern they did when one properly arranged them. In that regard explaining species change looks rather like a subsidiary project for Lamarck, but he knew he had to address it head on. Thus in 1803, having introduced his general theory to his students the previous year, he made the focus of his introductory lecture of 1803 "that great question of natural history, what is the species among living things?"
Lamarck recognized that he was up against religious as well as scientific orthodoxy in his belief that species changed. He proceeded to argue that the presumed stability of species was only an appearance, a result of failing to appreciate the immense amount of time nature had at her disposal when it came to bringing about change. As for the belief that species were as old as nature and the result of an initial creation by "the supreme author of all things," Lamarck readily acknowledged that "nothing exists except by the wish of the supreme author of all things," but he proposed that it was only through observation that one could identify "the mode that [the supreme author] was pleased to follow in this regard."
Lamarck was confident that his theory could handle even the most problematic cases. "Would one dare carry the spirit of system-building [l'esprit de systême] so far," he asked,
as to say that it is nature, by herself, that created this astonishing diversity of means, ruses, cunning, precautions, and patience of which the industry of animals offers us so many examples? Is not what we observe with the class of insects a thousand times greater than what is necessary to make us perceive that the limits of nature's power in no way allow her to produce so many marvels herself? And to force the most obstinate philosopher to recognize that here the will of the supreme author of all things has been necessary and has been alone sufficient to bring into existence so many admirable things?
Lamarck was not daunted. Nature, he allowed, had the faculty to produce all the marvelous examples of instincts and industry in animals — and reason as well. There was nothing irreligious about this view, he claimed, for it was in the supreme author's power to will that nature have this faculty. Furthermore, there was no reason to admire less the power of the "supreme cause of everything" if it pleased it to operate in this way rather than having to occupy itself with all the details of every particular creation as well as all the changes these creations would then undergo over time.
(Continues…)
Excerpted from "Dreamers, Visionaries, and Revolutionaries in the Life Sciences"
by .
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