Pulitzer Prize winner Jason Roberts: “One of the great challenges of today's world is its simplicity, that everything is easy to understand.”

True science has always been a matter of life and death. From the expedition to vaccinate Americans against smallpox to Iranian nuclear engineers, including the scientific race of the 1980s and 1990s to stop AIDS. In the 18th century, the Swedish naturalist Carl Linnaeus sent his followers around the world in search of as many species as possible to complete his classification of all living beings. Many never returned. Christopher Tärnström died of tropical fever en route to China; Pehr Löfling was killed by malaria in Venezuela; Carl Fredrik Adler died on the coast of Java; and Peher Forsskål died in Yemen. Jason Roberts (Los Angeles, USA, 63) considered writing a book about the adventures of these Enlightenment heroes, but when he began to delve deeper into their lives and those of his mentor, he saw that "they weren't very enlightened." Thus began the gestation of All Living Things (Taurus), which this year won the Pulitzer Prize for Biography.

As Roberts recounts in a video chat, Linnaeus’s effort to classify life—which left us the Latin binomial nomenclature system for species ( Homo sapiens ), embodied in his Systema Naturae —was also an attempt to dominate nature and other peoples, an impulse that materialized in the colonialism of the decades after his death in 1778. While Roberts delved into the Swede’s life, the figure of another scientist, Georges-Louis Leclerc, Comte de Buffon, grew, who produced his own enormous compendium of existing life in his Histoire naturelle .

Both have been portrayed by the American writer in a double biography that is also a story about the ideas that transformed our way of understanding life. These two contemporary scientists, who confronted their ideas but never met in person, also represented two opposing ways of confronting existence. In contrast to the power of knowledge to dominate the world embodied by Linnaeus, Buffon represented the capacity of science to assimilate complexity.

Question: I have the feeling that you find Buffon more accurate and even more sympathetic than Linnaeus. Yet, for many years, it seemed that Linnaeus, with his rigid way of interpreting nature, was the winner. Why do you think his ideas, at least for a time, were more appealing?

Answer: It took me a while to understand it. I discovered that Linnaeus's system fit perfectly with the spirit of the times, particularly with the British Empire and American expansion. People wanted certainty. They didn't want uncertainty. And they weren't interested in listening to Native cultures.

In many ways, the Linnaean system became a form of cultural colonialism, because it allowed you to wipe the slate clean and give a species a new name. But not only that, it also implied the idea that everything was fixed, that there was a specific order, that there were no surprises, and that Linnaeus had arrived at a kind of divine insight into how life was organized. In fact, that's why he was called "God's recorder."

Meanwhile, Buffon's vision was much more disturbing to them, though also much more dynamic. Buffon was the first person to say that we are living in the age of humans, that humans are permanently changing the global climate. And that was something that was ridiculed in his time. He was a proponent of the concept of evolution, before that word existed, and also of extinction.

And the more I investigated, the more I understood how Buffon had hidden his ideas within his work, because he knew very well that the era wasn't ready for some of his ideas. This made him an even more interesting figure to me.

Q. It also seems that in a time of uncertainty like the one that followed their deaths, with the French Revolution and the Napoleonic Wars, that precise, closed model of how the world works was preferred. A bit like today.

A. Absolutely. I agree with you that one of the great challenges of today's culture is the appeal of simplicity. And I wonder if this isn't a reaction many people have to feeling overwhelmed by the enormous amount of information we receive at once. They seek to extract order from chaos and don't want to feel unintelligent. I think that's one of the appeals of hypersimplistic worldviews: they give people the feeling that they can understand things, that everything is easy.

I'm seeing many trends that are anti-intellectual, but also anti-conflict. The current American political system is a textbook example of simplistic thinking trying to impose itself on a very complex political reality. There's this idea that when intellectuals say something is complicated, they're just trying to act smart, and that in reality, everything would be solved with a little common sense. I think the ability to appreciate complexity—to recognize that we don't necessarily understand everything—is a social value we need to rediscover.

Q. In the book, you also talk about the simplicity of the Linean system, which provides security and gives the impression, even to non-specialists, that you can control nature in a simple way.

A. The metaphor that Buffon himself proposed—and which I adopted—is the difference between a mask and a veil. He personified nature as a kind of veiled Mother Nature. He said that we can only occasionally glimpse some of its workings behind the veil, and that only with a great deal of patience and time. For him, the Linnaean world tree was like imposing a mask on nature: slapping a false face on it and saying, "This is what there is, this is how it works." And that, in doing so, a lot was lost.

Buffon had an open mind; he allowed himself to be constantly surprised by nature. Instead of explaining it away and normalizing everything, he relied on that sense of wonder. And that's how he managed to write almost 30 volumes describing nature, with prose that is a true literary flight, because he tried to capture what it felt like to be in the presence of these animals. And that's completely different from the sober "this is what there is" catalog, where things are reduced to a few words, as if trying to stick an insect in a box with a label and say "this is it."

So what I tried to do in this book was to propose something like Buffon. Because, as I said, I didn't start the project with a preference for one or the other. What I did was look for where the surprises lay, and try to understand where my expectations fell apart.

Q. Where did you find the biggest surprises?

A. I came across things like Buffon talking, essentially, about the concept of DNA. More than two centuries before it became a science. He said something like, "If there are these principles that nature follows to create an animal from gestation, from the moment it's an embryo, then there must be some kind of structure, some internal mold, a force that shapes it." And what happens is that, over time, there are small variations in those instructions. Those differences could be the origin of evolution.

One of the anecdotes I include in the book is that Darwin, who had never initially read Buffon, said when he finally did, "His ideas were disconcertingly similar to my own." And in The Origin of Species, he included a note crediting Buffon for being the first to address these ideas scientifically.

Q. Did being a great mathematician help Buffon develop these ideas, to better understand the inner workings of living beings? Because he wrote about biology in the 18th century with great foresight.

A. That interests me. When you look at the personalities of these two men, you'd think their philosophies would be interchanged. Buffon was the one with a refined mathematical mind, incredibly disciplined, very organized, and lived his life according to very rigid standards. You'd think he'd be the one more attracted to categories, the one who imposed structures on nature. Whereas Linnaeus, emotional and impulsive, did things you wouldn't imagine a professor would do, like break into one of his students' apartments and steal specimens he'd given them. You'd think he'd be the one with the more fluid understanding. But it was the other way around.

And that tells me that if Buffon, with all his sense of order, ended up admitting that we can't—at least at this point in the human experience—capture lightning in a bottle and say we understand what's happening in nature, then maybe that's precisely what we need to embrace. The idea that to understand nature, to help save it, we have to acknowledge what we don't know, is something we're just beginning to understand.

Q. How can this awareness of complexity help us, rather than taking away our self-confidence and making things more difficult for us?

A. Last year, for example, it was discovered that where we thought there was only one species of giraffe, there were actually four , which completely changes the conservation effort. It was information that was right under our noses, but we didn't see it because we had fallen into this kind of complacency induced by labels and appearances.

Meanwhile, there's one particular type of marine mollusk—a sea snail—that's been classified as a different species more than 200 times, and it turns out it's actually just one species. This idea that we've been forcing categorization on nature, and that maybe our eyes are starting to clear up a little, couldn't have come a minute later. Because if we really want to understand what we're doing to the planet, to our place in nature, and how we can maintain a safe environment, that idea of the environment as a rigid set of little labels isn't going to work. We're going to have to embrace complexity in order to understand nature, because we are part of that complexity.

Q. I don't know if you think that the fact that Linnaeus classified us as Homo sapiens , attributing rationality to us as a fundamental trait, has generated a misunderstanding and has generated overly high expectations of our species.

A. What I really struggled to forgive Linnaeus for was that he assigned what we now consider racial categories. The thing is, much of this book is set in a time before the terminology took on the meaning it has today. At that time, the term race wasn't used in the current sense. It simply meant any group that was referred to as a unit: you might talk about the "race of the Spanish" or "the human race." So Linnaeus didn't use the word race in that sense; he may have been thinking more of subspecies or something like that. He didn't label it as such, but he was the one who divided Homo sapiens into four categories. And that, based on external appearance, skin color, could be understood as a cultural error or a lack of vision. But what he did—and this surprised me—was add emotional values to them.

He said, for example, that Homo sapiens africanus was guided by whim, whereas the European was guided by law. That kind of classification literally injected these kinds of ideas into what we call science today, from the very beginning. While I was writing the book, the Linnean Society of London issued a statement acknowledging that the roots of scientific racism can be traced back to Linnaeus, and that it's a part of his legacy they are trying to revisit.