I emphasize this principle because false taxonomies—based on sensible criteria at first but then persisting as traditions that can only be deemed arbitrary (at best) or harmful (at worst)—form a potent category of mental biases that becloud our view of empirical nature and our moral compass as well. My fellow scientists seem particularly subject to this species of blindness because we have been trained to think that we see the world objectively. We therefore become specially subject to delusion by taxonomic schemes implanted in our minds by cultural traditions of learning but falsely regarded as expressing an objective natural reality.
Becher’s bibliography of 1671, now sensibly ordered by last names.
To present an example of tradition’s power to reach forward from arbitrary beginnings by imposing false taxonomies upon human thought, let me return to the Bauhins—this time, to the brother hidden by Caspar among his Johns. Strange as this fact may sound to modern ears, the first half-century of modern paleontology—from Agricola’s first printed treatise of 1546 up to 1600—included virtually no illustrations of fossils in published sources, although botanical traditions for illustration had already led to the production of several elaborate, lavishly illustrated herbals. Agricola’s long and elegantly printed treatise included no pictures—and neither did the great source from antiquity, Pliny’s Natural History. I can think of only four or five sixteenth-century sources that printed any illustrations of fossils at all, and only two of these works feature series of drawings that could be called either extensive or systematic—De Rerum Fossilium, the 1565 treatise by the great Swiss polymath Conrad Gesner, and a 1598 monograph on the medicinal waters and surrounding natural environments of the German fountains at Boll by Jean Bauhin (who as a young man had studied and then collaborated with Gesner).
Gesner’s work presents a general exemplification, not a report about a specific collection from a particular place. Gesner therefore provided simple woodcut illustrations for one or two specimens from each major group of “fossils” then known in Europe (a heterogeneous assemblage by modern standards, including paleolithic hand axes then interpreted as stones that fell from the sky in thunderstorms, and sea urchins then interpreted by some scholars as serpents’ eggs).
Bauhin’s treatise, on the other hand, represents a true beginning for an important tradition in science: the depiction not only of characteristic forms or representative specimens, but an attempt to present the full range of variety found in a particular fauna—in other words, to “draw ’em all just as one sees ’em,” without any confusing selection or interpretation. In fact, in his very few paragraphs of introductory text, Bauhin tells us that he will simply show what he sees and not enter the brewing debate about the meaning of fossils. For that fascinating but (for his purposes) diversionary activity, readers will have to consult (he pointedly tells us) the aforementioned scholarly works of Agricola and Gesner. He, Jean Bauhin, nature’s humble servant, will simply draw the fossils he has found and let readers draw their own conclusions.
Bauhin’s fifty-three pages and 211 drawings therefore mark the first printed presentation of a complete set of fossil specimens from a particular place. In consulting his treatise, we are truly “present at the creation” of an important tradition in the depiction and classification of nature’s bountiful variety. But however much we appreciate the privilege, and however appropriately we admire Bauhin’s originality, we should also bear the theme of this essay in mind and ask some crucial questions about cultural practices: What conventions did Bauhin invent in creating this genre? Did his rules and customs make sense in his day? Did they then become arbitrary impediments to increasing knowledge, masquerading as an “obvious” way to present “objective” facts of nature?
Bauhin’s attempt to devise an iconographic convention for distinguishing apples from pears, by drawing apples with stems down and pears with stems up, from his 1598 treatise.
As a striking proof that our iconographic traditions may originate as arbitrary inventions of idiosyncratic beginners, we need only consider the chapter following the opening section on fossils in Bauhin’s 1598 treatise—his discussion of variation in local pears and apples. The average apple couldn’t be confused with the average pear, but so many forms of both fruits had been developed in this region of Germany that extensive overlap could lead to uncertainties for dumpy and elongated apples or for compressed and top-heavy pears. Bauhin therefore invented the practice of drawing all the apples stem down and all the pears stem up!
Bauhin’s convention did not take hold, so we tend to view his illustrations as rather quaint—and the purely arbitrary character of his decision stands out clearly to us today. But suppose that his practice had endured. Wouldn’t we be wondering today why Delicious goes down and Bartlett goes up? Or, more interesting to contemplate, would we be pondering this issue at all? Perhaps we would simply be accepting a printed orientation that we had seen throughout life, never bothering to question the evident discrepancy with nature’s obedience to gravity, where both fruits hang down from stems. (Or perhaps, as city folks dwelling in concrete jungles, we would never even realize that nature works differently from art. Honest, growing up as a New York City street kid, I really didn’t know for a long time that milk came out of cows’ teats—yuck!—rather than from bottles ab initio.)
This example may strike readers as silly. But we follow similarly arbitrary conventions and mistake them for natural reality all the time. Anglophone publications, for example, always draw snails with the apex (the pointy end) on top and the aperture at the bottom. This orientation seems so obviously natural to me—apex up, aperture down. Of course—how else could a snail be? But French publications—and I do not know how or why the differences in practice began—usually draw snails in the opposite orientation, with the apex pointing down and the aperture up. So millions of Frenchmen must be wrong, n’est-ce pas? But when you learn about the difference and then allow yourself to consider the issue for the first time, you suddenly realize—and the insight can be quite salutary—that the French and English solutions might as well be Bauhin’s pears and apples. Neither mode can possibly be called correct by cor-respondence to nature. Most snails crawl horizontally along the substrate. Both ends of the shell lie basically parallel to the sea floor. Neither can be labeled as intrinsically up or down.
In another example that caused me some personal embarrassment but also taught me something important about convention versus nature, I once wrote that the North Pole pointed up and that our planet rotated counterclockwise around this axis (viewed, as by God or an astronaut, from above). An Australian reader wrote me a letter, gently pointing out the absence of absolute “up” or “down” in the cosmos and reminding me that our cartographic convention only reflects where most map-making Europeans live. From his patriotic vantage (and accepting another dubious convention that equates “up” with “good”), the Antarctic Pole points up, and Earth rotates clockwise around this southern standard.
The situation becomes even more complicated, and even more evidently ruled by convention, when we consider the history of cartography. In many medieval maps, drawn under the Ptolemaic notion of a central and nonrotating Earth, east—the direction of the rising Sun—occupies the top of the map. The word orient—meaning “east,” but with an etymology of “rising” in reference to the sun—gained the additional and more symbolic definition of “locating one’s position,” because east once occupied this favored top spot on our standard maps. (The Chinese used to be called Orientals for the same reason, before the term lapsed from political correctness, while Europeans became Occidentals, or westerners, in literal reference to the “falling down,” or setting, of the Sun.)
When we survey Bauhin’s more than two hundred fossil drawings, the largest single cache of sixteenth-century paleontological illustrations, we note the origin of several conventions that, although superseded today (and therefore unknown to most modern scientists), seriously impeded, for nearly two centuries, a proper un
derstanding of the nature of fossils and the history of life. Consider just three classes of examples, all based on the taxonomic conventions of sixteenth-century paleontology. The recognition of Bauhin’s illustrations as conventional rather than natural, and their replacement, by the end of the eighteenth century, with “modern” figures that clearly depict fossils as ancient organisms, virtually defines the primary shift in understanding that led to our greatest gain in knowledge during the early history of paleontology.
1.Conflation of categories. In Bauhin’s day, the word fossil—derived from the past participle of the Latin verb fodere, meaning “to dig up”—referred to any object of distinctive form found within the earth, thus placing the remains of ancient organisms in the same general category as crystals, stalactites, and a wide range of other inorganic objects. Until organic remains could be recognized as distinctive, placed in a category of their own, and properly interpreted as the products of history, modern geology, with its central concept of continuous change through deep time, could not replace the reigning paradigm of an Earth only a few thousand years old and created pretty much as we find it today, with the possible exception of changes wrought by Noah’s universal flood.
If fossils originated within rocks as products of the mineral kingdom, just as crystals grow in mines and stalactites form in caves, then a petrified “shell” may just denote one kind of inorganic object manufactured in its proper place within the mineral kingdom. Thus, when Bauhin places his drawing of a fossil snail shell right next to a conical mound of crystals because both share a roughly similar shape and supposed mode of inorganic origin, this taxonomic convention does not merely record a neutral “fact” of pure observation, as Bauhin claimed. Rather, his juxtaposition of two objects now viewed as fundamentally different in origin and meaning expresses a theory about the structure of nature and the pattern of history—a worldview, moreover, that stood firmly against one of the great revolutions in the history of scientific understanding: the depth of time and the extent of change.
Bauhin’s taxonomy places a fossil snail shell next to an inorganic mass of crystals because both have roughly the same shape.
2. Failure to distinguish accidental resemblance from genuine embodiment. Contrary to a common impression, Jean Bauhin and his contemporaries did not claim that all fossils must be inorganic in origin and that none could represent the petrified remains of former plants and animals. Rather, they failed to make a sharp taxonomic distinction between specimens that they did regard as organic remains and other rocks that struck them as curious or meaningful for their resemblance to organisms or human artifacts, even though they had presumably formed as inorganic products of the mineral kingdom. Thus, Bauhin includes an entire page of six rocks that resemble male genitalia, while another page features an aggregate of crystals with striking similarity in form to the helmet and head covering in a suit of armor. He does not regard the rocks as actual fossilized penises and testicles, and he certainly doesn’t interpret the “helmet” as a shrunken trophy from the Battle of Agincourt. But his taxonomic juxtaposition of recognized mineral accidents with suspected organic remains does lump apples and oranges together (or, should I say, apples and pears, without a stem-up-or-down convention to permit a fruitful separation), thereby strongly impeding our ability to identify distinct causes and modes of origin for genuine fossil plants and animals.
Bauhin’s caption reads: “a helmeted head made of pyrite”—an accidental resemblance that he regarded as meaningful, at least in a symbolic sense.
Bauhin’s 1598 illustration of six rocks that resemble penises. He did not regard them as actual fossils of human parts, but he did interpret, as causally meaningful, a likeness that we now regard as accidental.
3.Drawing organic fossils with errors that preclude insight into their origins. Bauhin claimed that he drew only what he saw with his eyes, unencumbered by theories about the nature of objects. We may applaud this ideal, but we must also recognize the practical impossibility of full realization. What can be more intricate and complex than a variegated rock filled with fossils (most in fragmentary condition), mineral grains, and sedimentary features of bedding followed by later cracking and fracturing? Accurate drawing requires that an artist embrace some kind of theory about the nature of these objects, if only to organize such a jumble of observations into something coherent enough to draw.
Since Bauhin did not properly interpret many of his objects as shells of ancient organisms that had grown bigger during their lifetimes, he drew several specimens with errors that, if accepted as literal representations, would have precluded their organic status. For example, he tried to represent the growth lines of a fossil clam, but he drew them as a series of concentric circles—implying impossible growth from a point on the surface of one of the valves—rather than as a set of expanding shell margins radiating from a starting point at the edge of the shell where the two valves hinge together.
Bauhin also drew many ammonite shells fairly accurately, but these extinct relatives of the chambered nautilus grew with continually enlarging whorls (as the animal inside increased in size). Bauhin presents several of his ammonites, however, with a final whorl distinctly smaller than preceding volutions from a younger stage of growth. Reading this error literally, an observer would conclude that these shells could not have belonged to living and growing organisms. Finally, in the most telling example of all, Bauhin drew three belemnites (cylindrical internal shells of squidlike animals) in vertical orientation, covered with a layer of inorganic crystals on top—clearly implying that these objects grew inorganically, like stalactites hanging from the roof of a cave.
The final whorl of this fossil ammonite becomes smaller, showing that Bauhin did not recognize the object as a fossil organism whose shell would have increased in width during growth.
Bauhin’s most telling example of iconographic conventions that he established and that show his misunderstanding of the organic nature of fossils. He draws these three belemnites (internal shells of extinct squidlike animals) as if they were inorganic stalactites hanging down from the ceiling of a cave.
Bauhin draws this fossil clam shell incorrectly, with growth lines as concentric circles. He did not recognize the object as the remains of an organism that could not grow in such a manner.
So long as later scientists followed these three iconographic conventions that Bauhin developed in 1598, paleontology could not establish the key principle for a scientific understanding of life’s history: a clear taxonomic separation of genuine organic remains from all the confusing inorganic objects that had once been lumped together with them into the heterogeneous category of “figured stones”—an overextended set of specimens far too diffuse in form, and far too disparate in origin, to yield any useful common explanations. These early conventions of drawing and classification persisted until the late eighteenth century, thus impeding our understanding about the age of the Earth and the history of life’s changes. Even the word fossil did not achieve its modern restriction to organic remains until the early years of the nineteenth century.
I do not exhume this forgotten story to blame Jean Bauhin for establishing a tradition of drawing that made sense when naturalists did not understand the meaning of fossils and had not yet separated organic remains from mineral productions—a tradition that soon ceased to provide an adequate framework and then acted as an impediment to more-productive taxonomies. The dead bear no responsibility for the failures of the living to correct their inevitable errors.
I would rather praise the Bauhin brothers for their greatest accomplishment in the subject of their primary joint expertise—botanical taxonomy. Brother Caspar of the bezoar stone published his greatest work, Pinax, in 1623—a taxonomic system for the names of some six thousand plants, representing forty years of his concentrated labor. Brother Jean of the fossils of Boll had been dead for thirty-seven years before his greatest work, Historia plantarum universalis, achieved posthumous publication in 1650, with even more elab
orate descriptions and synonyms of 5,226 distinct kinds of plants.
Botanical taxonomy before the Bauhin brothers had generally followed capricious conventions of human convenience rather than attempting to determine any natural basis for resemblances among various forms of plants (several previous naturalists had simply listed the names of plants in alphabetical order). The Bauhin brothers dedicated themselves to the first truly systematic search for a “natural” taxonomy based on principles of order intrinsic to plants themselves. (They would have interpreted this natural order as a record of God’s creative intentions; we would offer a different explanation in terms of genealogical affinity produced by evolutionary change. But the value of simply deciding to search for a “natural” classification precedes and transcends the virtue of any subsequent attempt to unravel the causes of order.)
Caspar Bauhin may have slightly impeded the progress of bibliography by retaining an outmoded system in his bezoar book. Jean Bauhin may have stymied the development of paleontology in a more serious manner by establishing iconographic conventions that soon ceased to make sense but that later scientists retained for lack of courage or imagination. But the Bauhin brothers vastly superseded these less successful efforts with their brilliant work on the fruitful basis of botanical taxonomy. Their system, in fact, featured a close approach to the practice of binomial nomenclature, as later codified by Linnaeus in mid-eighteenth-century works that still serve as the basis for modern taxonomy of both plants and animals.