In the eighteenth century, human knowledge was not as compartmentalized as it is today. Indeed, the boundaries between intellectual disciplines that we now view as distinct remained tenaciously blurry until remarkably recently. To give just one example, your admittedly venerable reviewer once attended a university that still awarded its physics and chemistry graduates degrees in natural philosophy, while those who actually studied philosophy received theirs in the moral sciences. This difference goes a long way toward explaining why, from the perspective of our own age of specialization, it is so hard for us to appreciate just how different our planet must have appeared to the people who were observing it during the era in which the fledgling United States declared its independence and the French staged their revolution.

Back then the age of discovery was at its peak, and startling new information about what had previously been a very parochial planet was flooding into the academies of Europe and the Americas. Inevitably, much of that knowledge was still undigested and poorly sorted; as a result the planet, viewed from Europe, must have seemed a rather impressionistic and formless place. The elaborate vocabulary that we now depend on for attributing structure to it, and thereby for grasping how it works, didn’t yet exist.

In no realm of knowledge was this lack more apparent than our understanding of how Earth’s riotously diverse biota was organized. By the late eighteenth century important progress had newly been made by the Swedish savant Carl Linnaeus in the practice of naming and classifying living things, but even the great classifier was content to believe that the world he so energetically strove to systematize was simply the way the Creator had wanted it to be.^* No further explanation of its form was required.

One of Linnaeus’s immense achievements was to brush aside the prevailing view, ultimately derived from Aristotle two millennia earlier, that all things had their ordained place on a great and continuous “Ladder of Nature” that extended from the inert minerals and pond scum at the bottom all the way up through mammals and humans to the heavenly realm at the top. But Linnaeus’s world was nonetheless a static and unchanging one, fixed at the Creation, which, by the 1650 reckoning of the Irish archbishop James Ussher, had occurred at 6:00 PM on October 22, 4004 BC, conveniently at the beginning of the academic year. It was not until 1785 that the Scottish geologist James Hutton had the temerity to turn convention on its head and evoke a dynamic planet in a continuous state of flux, with “no vestige of a beginning, no prospect of an end.”

The possibilities opened up by Hutton were as limitless as they were radical. And as unpalatable as they might have been to an establishment that feared any kind of instability, they also opened the way to a wholly new perspective on the history of Earth’s biota. That fact did not pass totally unremarked: in 1796, barely a decade after the Scotsman had presented his conclusions to the Royal Society of Edinburgh, the English physician Erasmus Darwin asked:

Would it be too bold to imagine, that in the great length of time, since the earth began to exist, perhaps millions of ages before the commencement of the history of mankind…that all warm-blooded animals have arisen from one living filament, which THE GREAT FIRST CAUSE endued with animality, with the power of acquiring new parts…possessing the faculty of continuing to improve by its own inherent activity, and of delivering down those improvements by generation to its posterity.

Those words certainly contain central elements of a theory of evolution, the idea that the distinctive pattern of resemblances (basically, of groups within groups) that we see among the many millions of living species on our planet is due to what Erasmus’s grandson Charles would later succinctly characterize as “descent with modification.” But at the time, like similar speculations that occasionally popped up, Erasmus Darwin’s words did not mark any general shift in either popular or scientific understanding of the natural world. Instead they fell into the general category of musings such as those of the eighth-century Arab intellectual al-Jahiz, who, according to the science historian Jim al-Khalili, had already hazarded a thousand years earlier that

animals engage in a struggle for existence; for resources, to avoid being eaten and to breed. Environmental factors influence organisms to develop new characteristics to ensure survival, thus transforming into new species. Animals that can survive to breed can pass on their successful characteristics to their offspring.

That and similar isolated conjectures were powerful, but they were flashes of intuition not embedded in any established program of inquiry within which they could be tested and extended. As a result, as the nineteenth century neared, natural historians in Europe were still solidly creationist in outlook. It would take a political and intellectual shake-up on the scale of the French Revolution to change that.

Career paths in the eighteenth century were just as haphazard as knowledge itself, and that of Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck, was an excellent case in point. The subject of Jessica Riskin’s engaging new book, The Power of Life, Lamarck was born in 1744 as the last of eleven children in a provincial military family of limited means. Under the ancien régime a military commission was an expensive thing, so a more economical clerical vocation was envisaged for the youngest child, who detested the idea. So unappealing did he find it that at the tender age of seventeen Lamarck contrived to obtain a junior commission in the French army at the height of the Seven Years’ War. He arrived at the front just in time to participate in the Battle of Vellinghausen, in which he managed to distinguish himself despite the routing of the French. He went on to serve his regiment for seven years, until he was eventually sidelined by a neck injury.

After trying his hand at music (which he loved) and banking (which he hated), Lamarck took a year off, living in the Parisian countryside. There he met Jean-Jacques Rousseau, who reawakened in him an interest in botany that eventually culminated in the publication, in 1778, of Flore française, a groundbreaking reference work that allowed its users to identify plants using the “either/or” dichotomous key system still familiar from field guides today. The book gained Lamarck some welcome financial liquidity along with both the patronage of France’s foremost natural historian, Georges-Louis Leclerc, comte de Buffon, and an association with the Royal Academy of Sciences. The well-connected Buffon’s support also brought Lamarck a corresponding membership in the Jardin du Roi, a magnificently idiosyncratic institution of informal research and education that had grown up around the plot of land on the left bank of the Seine where medicinal plants were cultivated for the king’s use.

While he was further ingratiating himself with Buffon by conducting the latter’s son on various journeys around Europe, Lamarck began to develop a notion that all minerals derived from organic matter and that between them plants and animals had somehow “composed” the material world as we see it now. That line of thought ultimately went nowhere (although the concept that minerals do indeed “evolve” is burgeoning today), but critically, it embraced for the first time the modern idea of a nonstatic and transformational world.

Then came the Revolution. As the old apparatus of state fell apart and the Académie Royale des Sciences was abolished, the strangely egalitarian Jardin du Roi (astutely renamed the Jardin des Plantes, on Lamarck’s initiative) became a hotbed of intrigue. Eventually, in 1793, the Museum of Natural History was established around it, with an assembly of twelve professors to run the operation. Following extensive jockeying, Lamarck wound up with the twelfth and implicitly lowliest professorship, in the “Natural History of Insects and Worms”—it wasn’t the post he wanted, but he quickly came to take his remit seriously.

Riskin gives a good sense of the tenor of the times:

On June 10, 1793…he arrived at this curious pass: Upon going to bed the night before, he’d been a botanist, but that day the revolutionary committee in charge of reorganizing the King’s Garden, with a stroke of its pen, turned him into—not a frog, exactly—but a zoologist. Robespierre was maneuvering into position at the helm of the Committee of Public Safety, accelerating the use of the guillotine to separate the heads from the necks of many aristocrats and anyone else the committee deemed counterrevolutionary. Lamarck, a middle-aged widower with six children, had little choice. He kept his head but had to remake himself overnight in middle age, leaving botany to take up the professorship in insects and worms, creatures about which he knew, as yet, very little.

Whatever his strengths, Lamarck was not a great diplomat, and one of his early actions at the new museum was to foster a future enmity by passing over the fast-rising comparative anatomist Georges Cuvier for a job there as aide-naturalist. Cuvier, who was shortly thereafter hired by another professor and would rapidly become the most influential French biologist of his time, was a convinced creationist and utterly opposed to Lamarck’s emerging ideas about the dynamic nature of the living world. Renowned for his “principle of correspondence of parts,” which saw every organism as so optimally designed that the structure of any part could be inferred from those adjacent to it, Cuvier was wedded to the idea that species were fixed and unchangeable. He saw the extinctions and replacements of ancient faunas that were already evident in the nascent fossil record as evidence for a succession of natural “catastrophes,” each followed by a subsequent recreation, the last such event having been Noah’s flood. It was to this intellectual foe that the task of eulogizing Lamarck would one day fall.

Lamarck made no secret of his disdain for Cuvier’s ideas, and over the years he continued to explore his insight that nature was in flux and that whether an organism’s traits were “perfect” or “imperfect” depended entirely on their suitability for the prevailing environment. He also heroically tackled the chaotic state of understanding of the insects and worms—living and fossil—that were now his official bailiwick, finding it necessary not only to fundamentally reorganize the classification of the group but to create an entirely new category of “invertebrates” for it.

Crucially, during those studies Lamarck discerned independent tendencies toward “complexity” within various branches of his invertebrates, most notably in fossil mollusks and gastropods from sedimentary rocks in the Paris Basin. Between 50 and 40 million years ago the region around the capital had intermittently been the bed of a warm, shallow sea, and Lamarck saw that many of the mollusks preserved from the time compared closely to their modern counterparts, while others did not and appeared to show change. Ironically, Cuvier also leaned heavily on Paris Basin fossils in developing his own ideas of catastrophism. From his many observations Lamarck developed not only his ideas of time-related change within lineages but also his notion of the “pouvoir de la vie,” a force that resides within living forms and that gives Riskin’s book its title. In Lamarck’s view, that force propelled organisms to move from lesser to greater states of complexity over time.

By the end of the eighteenth century Lamarck had become fairly confident that our planet’s biota had a long and dynamic history of what we would now call evolutionary change. And on May 11, 1800, he presented his students at the museum with a preliminary account of how he thought this had happened. Species, he told the students, are not immutably fixed by the Creator but instead change over time. Very simple organisms spontaneously emerge, and ultimately their descendants become behaviorally more complex in response to changing environments. The resulting bodily modifications accumulate adaptively within lineages as individuals in successive generations transmit to their offspring the physical alterations acquired during their lifetimes. Blacksmiths, for example, pass along their enhanced musculatures to their sons (usually blacksmiths themselves), while blind cave salamanders lose their eyes through disuse. In the most classic case, ancestral giraffes had stretched their necks ever longer as successive generations strove to browse ever higher in the trees.

In subsequent publications, notably his Philosophie zoologique of 1809, Lamarck quietly worked out his radical ideas of change. In postrevolutionary France his views were hardly a social threat, but they made little public impression, and his book sold slowly. As for the savant’s colleagues at the museum, with the exception of his supporter the zoologist Étienne Geoffroy Saint-Hilaire, they largely maintained a polite silence, whatever their private opinions might have been. Few journals saw fit to review the Philosophie zoologique, and its author made little additional effort to publicize his transformationist faith. As a result, while Lamarck’s potentially incendiary ideas were out there for anyone who cared to pay attention to them, few did.

Although Darwin would later readily admit his debt to Lamarck in his private notebooks, the French zoologist’s public obscurity lasted for the better part of a century. Frail and blind for the last decade of his life, Lamarck died in 1829 and was interred in what amounted to a pauper’s grave, his reputation dealt a final blow by Cuvier’s condemnation in the guise of a eulogy. Beginning with the declaration that “too great an indulgence of a lively imagination has led to results of a…questionable kind,” followed by a pro forma acknowledgment of Lamarck’s contribution to the systematics of the invertebrates, Cuvier proceeded to energetically lambaste virtually all other aspects of Lamarck’s post-botanical career. He reserved particular disdain for Lamarck’s belief that nature had a tendency to change:

A system established on such foundations may amuse the imagination of a poet; a metaphysician may derive from it an entirely new series of systems; but it cannot for a moment bear the examination of anyone who has dissected a hand, a viscus, or even a feather.

As far as Cuvier was concerned, Lamarck’s most creative speculations were simply not science.

The silence thus continued. In the decades after his death no one even bothered to take the deceased professor of insects and worms to task for espousing the inheritance of acquired characteristics. This is perhaps hardly surprising, since the idea went all the way back to Hippocrates and was more or less received wisdom in Lamarck’s day and beyond. And as it turned out, there are worse things than being ignored. During the 1880s, after the German biologist August Weismann had begun investigating the distinction between the cells composing the body tissues and those involved in heredity, Lamarck’s name began to be actively excoriated by practitioners of the nascent profession of genetics.

By the late nineteenth century, Darwin’s 1859 theory of evolution by natural selection had already become widely accepted (although his own suggested mechanism of heredity was about to be disproved by the advent of Mendelian genetics). But instead of being hailed for anticipating Darwin’s ideas of change, Lamarck was rapidly transformed into a whipping boy for failed evolutionary notions, and “Lamarckian inheritance” became a thoroughly dismissive pejorative, a byword for false theory. The unfortunate Frenchman’s name was further besmirched in the 1930s and 1940s when he was unjustly associated with the Soviet charlatan Trofim Lysenko, who persuaded Joseph Stalin to actively persecute conventional Mendelian plant geneticists.

All of that adds up to one of the most egregious injustices in the entire history of science, not least because fundamentally Lamarck had been right all along. In a society that viewed the world as static and unchanging, Lamarck was the first working scientist ever to recognize from empirical evidence that the fossil record was actually telling us otherwise: that the natural world we see today reflects a long history of physical change as, from the beginning, lineages of organisms have responded to environmental stimuli.

It is very difficult from our modern perspective to appreciate the sheer boldness and originality of Lamarck’s insight, which emerged from many years of pondering a bewildering variety of facts in the complete absence of any useful preexisting structure within which to organize them. As the paleontologist Niles Eldredge points out in his book Eternal Ephemera (2015), a penetrating analysis of the birth and development of evolutionary thought to which Riskin makes no reference, there are two basic elements in the modern view of evolution that we now trace back to Darwin: physical change within ancestor-descendant sequences of organisms and the splitting of those individual lineages. And the first of those crucial components, the idea that species or lineages of organisms can actually change over time, was the gift of Jean-Baptiste de Lamarck.

Interestingly, there was not long to wait before the second of Eldredge’s elements was added to the evolutionary mix. In 1814 the Italian geologist and botanist Giambattista Brocchi published a study of marine fossils from the Apennine Mountains in which he speculated that species, like individuals, had births, life spans, and deaths, and could give rise to descendant species (thereby splitting the lineage). Well within the first quarter of the nineteenth century, then, Lamarck and Brocchi had between them laid the groundwork for the theory of evolution that was to come half a century later; and as Riskin shows, toward the end of his life the French naturalist himself also came to explicitly embrace the importance of branching in evolution. It is not certain that Darwin ever read Brocchi’s work, although he very likely was at least indirectly aware of it, but he was certainly well versed in the writings of Lamarck, whom he deeply respected as an early transmutationist even as he rejected the inheritance of acquired characteristics.

If all Lamarck had ever done was to have been the first scientist to suggest that evolutionary change could occur, he would have earned an honored place in history. But he was also a man of profound inquisitiveness who lived in interesting times, to say the least. Riskin tells the story of his life with affection and in occasionally exhausting detail. The result is not just a biography of an individual scientist but a revealing account of French natural history during a tumultuous and formative period. Amid all the cut and thrust Riskin describes, Lamarck comes across as a remarkably sympathetic character. He emerges particularly well from the dismal episode of Saartjie Baartman, the “Hottentot Venus” who, as a young woman in 1810, was brought for exhibition from South Africa to London and Paris and who seems to have awakened an alarmingly prurient interest among the other learned professors at the museum.

Riskin follows Lamarck through a long succession of battles that includes his farsighted attempt to establish a national meteorological bureau. In the course of this initiative he had an unfortunate falling-out with Napoleon (for no better reason than that the newly crowned emperor uneasily shared a mistress with the minister who sponsored Lamarck), which culminated in an imperial instruction to “immediately cease all publications of his observations on the atmosphere.” Since the zoologist’s unruly vision of a self-making world was altogether incompatible with the emperor’s authoritarian centralizing, the relationship was probably doomed anyway. Yet it is still distressing to read how, when Lamarck attempted to present Napoleon with a copy of his Philosophie zoologique on its publication in 1809, the latter barely deigned to accept it.

Such discouraging experiences presumably contributed to Lamarck’s dim view of humankind in general. Fully prepared to apply his ideas about life to his own species, in the Philosophie zoologique he readily envisaged a transition from a “quadrumanous” (four-handed) ape into a “bimanous” human, behaviorally propelled by the abandonment of climbing in trees. He also recognized that the ultimate outcome was equivocal at best, the resulting high human intelligence conferring “the means for doing harm as easily as good.”

Having covered Lamarck’s life and achievements in absorbing detail, Riskin turns at the end of her book to later developments, among them the deterioration of his reputation as the science of genetics became established; the blossoming of neo-Darwinism, eugenics, and Lysenkoism; and such unfortunate incidents as the Midwife Toad scandal, in which the experimental biologist Paul Kammerer claimed to have induced physical change by forcing normally land-breeding toads to reproduce in water. The association of all of this with Lamarck is tenuous at best, and these excursions unhelpfully bring us back to what he was conventionally wrong about rather than what he was innovatively right about. One suspects they are there just because Riskin found it understandably difficult to say good-bye to her subject.

Fortunately, Riskin’s epilogue returns us to Lamarck the freethinking scientist, who can still speak directly to us today. Back at the height of the Industrial Revolution, Lamarck was already sounding the alarm on issues that were then invisible to most but have by now become existential. In his last book, written in 1820, when he was already ill and blind, he dwelled not only on the destructive results of human activities such as large-scale deforestation but on the dangers of ignoring their warning signs. “It looks,” he wrote, “as if man is destined to exterminate himself after making the globe uninhabitable.” That message is even more relevant now than it was when Lamarck penned it, two centuries ago.