The father of modern science recognized that internal psychological barriers to understanding nature were as constraining as sensory limitations.
We usually depict the Renaissance (literally, the Rebirth) as a clear, bubbling river of novelty that broke the medieval dam of rigidified scholasticism. But most participants in this great ferment cited the opposite of innovation as their motive. Renaissance thinkers and doers, as the name of their movement implied, looked backward, not forward, as they sought to rediscover and reinstitute the supposed perfection of intellect that Athens and Rome had achieved and a degraded Western culture had then forgotten.
I doubt that anyone ever called Francis Bacon (1561-1626) a modest man. Nonetheless, even the muse of ambition must have smiled at such an audacious gesture when this most important British philosopher since the death of William of Ockham in 1347, this chancellor of England (until his fall for financial improprieties), declared "all knowledge" as his "province" and announced that he would write a Great Instauration (defined by Webster's as "restoration after decay, lapse, or dilapidation"), both to codify the fruitful rules of reason and to summarize all useful results. As a procedural starting point, at the. dawn of a movement that would become modern science, Bacon rejected both the scholastic view that equated knowledge with conservation and the Renaissance reform that sought to recapture a long-lost perfection. Natural knowledge, he proclaimed, must be reconceptualized as a cumulative process of discovery, propelled by processing sensory data about the external world through the reasoning powers of the human brain.
Aristotle's writings on logic had been gathered into a compendium called the Organon (Tool). Bacon, with his usual flair, entitled the second book of his Instauratio Magna (Great Instauration) the Novum Organum, or new tool of reasoning, because the shift to such a different ideal--knowledge as cumulative and rooted in an increasing understanding of external reality--also demanded that the logic of reasoning itself be reexamined. Bacon therefore began the Novum Organum by analyzing impediments to our acquisition of accurate knowledge about the empirical world. Acknowledging the existence of such barriers required no novel insight. Aristotle himself had classified the common logical fallacies of human reasoning, while everyone recognized the external limits of missing data--stars too far away to study in detail (even with Galileo's newfangled telescope) or cities too long gone to leave any trace of their former existence.
But Bacon presented a brilliant and original analysis by concentrating instead on psychological barriers to knowledge about the natural world. He had, after all, envisioned the study of nature as a funneling of sensory data through mental processors, and he recognized that internal barriers at the second, or cerebral, stage could stand as high as the external impediments of sensory limitations. He also understood that the realm of conceptual hang-ups extended far beyond the cool, abstract logic of Aristotelian reason and into our interior world of fears, hopes, needs, feelings, and the structural limits of mental machinery. Bacon therefore developed a celebrated metaphor to classify these psychological barriers. He designated such impediments as idols and recognized four major categories--idola specus (of the cave), idola fori (of the forum, or marketplace), idola theatri (of the theater), and idola tribus (of the tribe).
Proceeding from the particular to the general, idols of the cave define the peculiarities of each individual. Some of us panic when we see a mathematical formula; others, for reasons of childhood suppression grafted upon basic temperament, dare not formulate thoughts that might challenge established orders. Idols of the marketplace, perhaps Bacon's most original concept, designate limits imposed by language--for how can we express, or even formulate, a concept that no words in our language can specify? (For example, in his brilliant story "Averroes' Search" Jorge Luis Borges--who loved Bacon's work and may well have written this tale to illustrate the idols--imagined the fruitless struggles of the greatest Arabic commentator on Aristotle to understand and translate the master's key concepts of "tragedy" and "comedy" for such notions could not be expressed, or even conceptualized, in Averroes's culture.)
Idols of the theater identify the most obvious category of impediments, based on older systems of thought. We will have one hell of a time trying to grasp Darwinism if we maintain absolute and unquestioned fealty to the "old-time religion" of Genesis literalism, with an Earth no more than a few thousand years old and all organisms created by a deity ex nihilo and in six days of twenty-four hours each. Finally, idols of the tribe--that is, our tribe of Homo sapiens--specify those foibles and errors of thinking that transcend the peculiarities of our diverse cultures and reflect the inherited structures and operations of the human brain. Idols of the tribe, in other words, lie deep within the constitution of what we call human nature itself.
Bacon emphasized two tribal idols in his examples: our tendency to explain all phenomena in the spatial and temporal vastness of the universe by familiar patterns in the only realm we know from the direct experience of our own bodies--that is, the domain of objects that live for a few decades and stand a few feet tall--and our propensity to make universal inferences from limited and biased observations, ignoring evident sources of data that do not impact our senses. (Bacon cites the lovely example of a culture convinced that the Sea God saves shipwrecked men who pray for his aid, because rescued sailors so testify. A skeptic, presented with this evidence, was asked "whether he did not now confess the divinity of Neptune and returned this counterquestion by way of answer: `Yea, but where are they painted, that are drowned?' And there is the same reason of all suchlike superstitions, as in astrology, dreams, divinations, and the rest.")
In the Great Instauration (written by Bacon in Latin and translated by Gilbert Wats in 1694), Bacon defines the idols in his characteristically pungent prose:
Idols are the profoundest fallacies of the mind of man. Nor do they deceive in particulars [that is, objects in the external world] ... but from a corrupt and crookedly-set predisposition of the mind; which cloth, as it were, wrest and inject all the anticipations of the understanding. For the mind of man ... is so far from being like a smooth, equal, and clearglass, which might sincerely take and reflect the beams of things, according to their true incidence; that it is rather like an enchanted glass, full of superstitions, apparitions, and impostures.
(Wats, Bacon's translator, called his subject "a learned man, happily the learned'st that ever lived since the decay of the Grecian and Roman empires, when learning was at a high pitch." Wats also appreciated Bacon's distinctive approach to defining the embryonic field of modern science as accumulating knowledge about the empirical world, obtained by passing sensory data through the biased processing machinery of the brain. Wats described Bacon as "the first that ever joyn'd rational and experimental philosophy in a regular correspondence, which before was either a subtilty of words, or a confusion of matter" He then epitomized Bacon's view in a striking image: "For Truth, as it reflects on us, is a congruent conformity of the intellect to the object ... when the intellectual globe, and the globe of the world, intermix their beams and irradiations, in a direct line of projection, to the generation of sciences.")
If our primary tribal idol resides in the ancient Greek proverb that "man [meaning all of us] is the measure of all things," then we should not be surprised to find our bodily fingerprints in nearly every assessment, even (or especially) in our words for abstractions--as in the strength of virility (from the Latin vir, an adult male), the immaturity of puerility (from puer, a boy), or the madness of hysteria (originally defined as an inherently feminine disease, from the Greek word for womb). However, in our proper objection to such sexual stereotyping, we may at least take wry comfort in a general rule of most Indo-European languages (not including English) that assign genders to nouns naming inanimate objects. Abstract concepts usually receive feminine designations--so the nobility of (manly) virtue presents herself as la vertu in France, while an even more distinctively manly virility also cross-dresses as la virilite.
We can, I believe, dig to an even deeper level in identifying tribal idols that probably lie in the evolved and inherited structures of neural wiring--the most basic and inherent substrate of "human nature" itself (if that ill-defined, overused, and much abused term has any meaning at all). Some properties of human thinking seem so general, so common to all people, that such an evolutionary encoding seems reasonable, at least as a working hypothesis. For example, neurologists have identified areas of the brain apparently dedicated to the perception of faces. (One can easily speculate about the evolutionary value of such a propensity, but we must also recognize that these inherent biases of perception can strongly distort our judgment in other circumstances--Bacon's reason for designating such mental preferences as idols--as when we think we see a face in the random pitting of a large sandstone block on Mars and then jump to conclusions about alien civilizations. I am not making this story up, by the way: the Martian face remains a staple of "proof" for the UFO and alien-abduction crowd.) I suspect that the neural mechanism for facial recognition becomes activated by the abstract pattern of two equal and adjacent circles with a line below--a configuration encountered in many places, not only in real faces.
In this "deeper" category of tribal idols, I doubt that any rule enjoys wider application, or engenders greater trouble at the same time, than our propensity for ordering nature by making dichotomous divisions into two opposite groups. (Claude Levi-Strauss and the French structuralists have based an entire theory of human nature and social history on this premise and two bits from this corner says they're right, even if a bit overextended in their application.) Thus, we start with a few basic divisions of male versus female and night versus day, and then we extend these concrete examples into greater generalities of nature versus culture ("the raw and the cooked," in Levi-Strauss's terminology), spirit versus matter (philosophical dualism), and the beautiful versus the sublime (in Burke's theory of aesthetics), and thence (and now often tragically) into ethical beliefs, anathematization, and sometimes warfare and genocide (the good versus the bad, the godly who must prevail versus the diabolical, ripe for burning).
Again, one can speculate about the evolutionary basis of such a strong propensity. In this case, I rather suspect that dichotomization represents some baggage from an evolutionary past of much simpler brains built only to reach those quick decisions--fight or flight, sleep or wake, mate or wait--that make all the difference in a Darwinian world. Perhaps we have never been able to transcend the mechanics of a machinery built to generate simple twofold divisions and have had to construct our greater complexities upon such a biased and inadequate substrate--perhaps the most limiting tribal idol of all.
I devoted the first part of this essay to a general discussion of our mental limitations because this framework, I believe, so well illuminates a particular problem in the history of paleontology that caught my fancy and attention, both for unusual intrigue in itself and for providing such an excellent test case of an important general pattern in the growth of scientific knowledge.
Classical authors, particularly Pliny in his Natural History, spoke in a limited way about fossils, usually (and correctly) attributing the shells found on mountaintops to a subsequent elevation of land from ancient seabeds. A few medieval authors (particularly Albert the Great in the thirteenth century) added some comments, while Leonardo da Vinci, in the Codex Leicester (written in the early 1500s), made extensive and brilliant paleontological observations that were, however, not published until the nineteenth century and therefore had no influence on the field's later development. Essentially, then, the modern history of paleontology began in the mid-sixteenth century with the publication of two great treatises on fossils by two remarkable scholars: the first published in 1546 by the German physician and mining engineer Georgius Agricola, and the second in 1565 (the year of the author's death in an epidemic of plague in Zurich) by the Swiss polymath Conrad Gesner.
In the compendium of Latinized folk names then used to identify fossils, most designations noted either a similarity in appearance to some natural or cultural phenomenon or a presumed and legendary mode of origin. Thus, the fiat and circular components of crinoid stems were called trochites, or wheel stones; the internal molds of rounded pairs of clamshells were bucardites, or bulls' hearts (see figure, left); well-rounded concretions of the appropriate size were enorchites, or testicle stones (and if three were joined together, they became triorchites, or "three balls"); and sea urchin tests were brontia, or thunder stones, because they supposedly fell from the sky in lightning storms.
A prominent group of fossils in this old taxonomy, and a puzzle (as we shall see) to early paleontologists, was called hysteroliths--also known, in various vernaculars, as woman stones, womb stones, mother stones, or vulva stones (with the scholarly name derived from the same root as "hysteria" an example cited earlier in this essay). The basis for this taxonomic consensus stands out in the first drawing of hysteroliths ever published--by the Danish natural historian Olaeus Worm in 1665. A prominent median slit on one side (sometimes both) of a rounded and flattened object can hardly fail to suggest the anatomical comparison--or, to cite Worm's own words, "quod muliebre pudendum figura exprimat"--"because the form imitates the female genitalia." (Unless otherwise noted, all translations from the literature on hysteroliths are mine, from Latin originals.) Interestingly, as. Worm's second figure (below) shows, the opposite side of some (but not all) hysteroliths seems to portray, albeit less obviously, a figure of the male counterpart (at right, below). The men who wrote the founding treatises of modern paleontology could hardly have failed to emphasize such a titillating object (especially in an age that provided few opportunities for approved and legitimate discussion and illustration of such intimate subjects).
This essay is not structured as a mystery yarn, so I spoil nothing, while (I hope) enhancing the intended intellectual theme by providing the true nature of hysteroliths up front. Hysteroliths are the internal molds of certain brachiopod shells (just as bucardites, discussed above, are internal molds of certain clamshells). Brachiopods are not closely related to clams, but they also grow shells made of two convex valves that open on a hinge located at one end of the shell and close by bringing the two valves together all along their edges. Therefore, if you make an internal mold by pouring plaster of paris into the closed shell, the resulting object will look roughly like a flattened sphere, with the degree of flattening specified by the convexity of the shell. Highly convex shells can produce nearly spherical molds (as in the fat clamshells that make bucardites). Shells of lower convexity--including most brachiopods and all the groups that make hysteroliths--yield more flattened molds.
Since molds are negative impressions of surrounding shapes, the suggestive parts of hysteroliths record features on the interior of a brachiopod shell in reverse. The slit that suggested a vulva and gave hysteroliths their name marks the negative impression of a raised and narrow linear ridge called the median septum--that runs right down the middle of many brachiopod shell interiors, effectively dividing the valve in half. (For a clarifying analogy, think of the ridge as a knife and the slit as a cut.) The less pronounced "male" features on the other side of some hysteroliths record, in positive relief, a cylindrical groove on the shell interior that houses part of the feeding skeleton (detached from the shell itself and rarely fossilized) in some groups of brachiopods.
By the mid-eighteenth century, paleontologists had reached a correct consensus. They knew that hysteroliths were internal molds of brachiopods, and they had also identified the particular kinds of brachiopods that left such impressions on their molds. They also recognized, of course, that the admittedly striking similarity with human genitalia recorded a sheer, if curious, accident, with no causal meaning or connection whatsoever.
We therefore obtain, in the story of hysteroliths, a clean, clear, and lovely example of science operating admirably by following the canonical definition of its very being and distinctiveness--a procedure dedicated to the sweetest of all goals: the construction of an accurate piece of natural knowledge. This odyssey through two centuries and several interesting stages progresses from the puzzled agnosticism of Agricola's first mention in 1546 to Linnaeus's unchallenged conclusion of 1753.
I certainly do not deny the broad outline of this story. Agricola and Gesner possessed few clues for choosing from a wide range of alternatives--from the correct answer that eventually prevailed, to an inorganic origin by plastic forces circulating through rocks, to generation by various ancient animals as a meaningful symbol that might even cure or alleviate human ailments of the genital organs. The correct answer may not have fulfilled all human hopes and uses, but hyseroliths really are brachiopod molds, and science supplied the tools for proper resolution.
I do, however, question the usual reading of such genuine scientific progress as a simple exercise in factual accumulation through accurate observation, guided by the objective principles of reasoning known as the scientific method. In this familiar model, the naivete of Agricola and Gesner arises from their lack of accurate knowledge, not from any mental failures or barriers. In this sense, these sixteenth-century scholars might well be us in miniature, with the diminution established by what they couldn't know but we have since learned by living several centuries later and enjoying the fruits of advancing scientific knowledge. But we should not so diminish such brilliant men and such interesting times. Gesner and Agricola cannot be judged as less worthy than we; they were only different from us (and probably a lot smarter than the vast majority of us) in viewing the world from entirely divergent points of view that would be fascinating for us to grasp and understand.
I particularly appreciate Bacon's metaphor of the idols, because this device can lead us toward a better appreciation of the complexities of creative thought and the unifying similarities between the style we now call science and all other modes of human insight and discovery (while acknowledging, of course, that science presides over distinct subject matter and pursues particular goals in trying to understand the factual character of a "real" external world). Bacon argued that we must filter sensory data about this world through mental processors and that these internal mechanisms always operate imperfectly because idols gum up the works. Discovery, therefore, arises from a complex intermeshing of these inside and outside components and not by the accumulated input of facts from the outside world, continually processed by a universal and unchanging machinery of internalized scientific logic.
Gesner did not use the same criteria that we employ today, with our differences then attributed to his tiny molehill of reliable facts compared with our mountain. Rather, the idols conspired in him (as they still do in us, but with different resulting blockages) to construct a distinct kind of processing machine. Science prospers as much by retuning, or demolishing and then rebuilding, such mental machinery as by accumulation of new factual information. Scientists don't simply observe and classify enough fossils until, one day, the status of hysteroliths as brachiopod molds becomes clear; rather, our theories about the nature of reality, and the meaning of explanation itself, must be decomposed and reconstructed before we can build a mental mansion to accommodate such information. And such reconstruction requires, above all, that we acknowledge, examine, and challenge the Baconian idols of our own interior world.
I argued at the beginning of this essay that the Baconian idols could be ordered by degree of generality. In tracing the history of the hysterolith problem, I noted an interesting progression in the release of blockages--from the most pervasive to the most particular idol--as paleontologists homed in on a solution over two centuries. Perhaps we must first dig the right kind of mine before we can find any particular nugget of great price.
1. Idols of the Tribe in the Sixteenth Century: Gesner and Agricola Rediscover Pliny and the Three Dichotomies. The hysterolith story begins as far back as the recorded history of paleontology can venture and as deeply as one can probe into the most pervasive and general of tribal idols, our propensity to dichotomize. Pliny the Elder, the great Roman statesman and natural historian who died with his boots on in the eruption of Mount Vesuvius in A.D. 79, wrote a compendium about the natural world that survived in legions of hand copies made by monks and other scholars for more than a millennium before Gutenberg, and then became one of the most widely published books in the first decades of printing. (In the trade, books printed before 1500 are called incunabulae, or "from the cradle.")
Agricola and Gesner, as Renaissance scholars committed to the recovery of ancient wisdom, sought above all to assign their specimens (and vernacular names) to forms and categories mentioned by Pliny in his Natural History. In an alphabetical list of rocks, minerals, and fossils placed in the thirty-seventh and last book of his great treatise, Pliny included a notable one-liner under the letter "D": "Diphyes duplex, candida ac nigra, mas ac femina"--"having the character of both sexes, white and black, male and female."
Pliny's treatise contained no pictures, so we cannot know what object he had meant to designate with such a sparse de******ion. But on the theme of tribal idols, I am fascinated that the first mention of a possible hysterolith features two of the most general impediments in this category: our tendency to read nature at all scales in terms of immediately familiar objects, particularly the human body, and our propensity for classification by dichotomy. In his single line, Pliny explicitly cites two of the most fundamental dichotomies: male and female, and white and black. (Later commentators assumed that Pliny's diphyes referred to stones that looked male on one side and female on the other--hence their identification with hysteroliths.)
Moreover, we should also note the implicit inclusion of a third great dichotomy--top and bottom--in Pliny's definition, for hysteroliths are built of two distinct and opposite halves: a stunning representation, literally set in stone, of our strongest mental idol, expressed geometrically. Moreover, all three dichotomies carry great emotional weight, both in their archetypal ideological status and in their embodiment of conventional rankings (by worth and moral status) in a hierarchical and xenophobic society: male, white, top versus female, black, bottom. Our modern perspective can only lead us to shiver when we grasp the full implication of such a multiply dichotomized classification.
In his De natura fossilium of 1546, the first published treatise on paleontology (the term "fossil" then designated any object found in the ground--a broad usage consistent with its status as past participle of the Latin verb fodere, "to dig up"--so this work treated all varieties of rocks and minerals, as well as the remains of organisms now exclusively called fossils), Agricola unearthed Pliny's one-liner, probably for the first time since antiquity, and applied the name diphyes to some fossils found near the fortress of Ehrenbreitstein. A generation later, in his De rerum fossilium (On fossil objects) of 1565, Gesner first connected Pliny's name and Agricola's objects with the folk designation and technical moniker--"hysterolith"--that would then denote this group of fossils until their status as brachiopod molds became clear two hundred years later.
Sixteenth-century paleontology proceeded no further with hysteroliths, but we should not undervalue the achievements of Agricola and Gesner in terms of their own expressed aims. As men of the Renaissance, they wished to unite modern observations with classical wisdom--and the application of Pliny's forgotten and undocumented name to a clear category of appropriate objects seemed, to them, an achievement worth celebrating.
Moreover, when we note Gesner's placement of hysteroliths within his general taxonomy of fossils, we can peek through this window into the different intellectual domain of sixteenth-century explanation and also begin to appreciate the general shifts in world view that would have to occur before hysteroliths could be recognized as brachiopod molds. Gesner established fifteen categories of fossil objects, mostly based on presumed resemblances to more familiar parts of nature and descending in decreasing worthiness from the most regular, heavenly, and ethereal to the roughest and lowest. The first category included geometric forms (fossils of circular or spherical shape, for example); the second brought together all fossils that recalled heavenly bodies (including the star-shaped elements of crinoid stems); while the third held stones that supposedly fell from the sky. At the other end, the disparaged fossils of category 15 resembled insects and serpents. Gesner placed hysteroliths into category 12, not at the bottom but not very near the honored pinnacle either, for "those that have some resemblance to men or quadrupedal animals, or are found within them." As his first illustration in category 12, Gesner drew a specimen of native silver that looked like a mat of human hair.
2. Idols of the Theater in the Seventeenth Century: Animal or Mineral, Useful Symbol or Meaningless Accident? If classic tribal idols played a founding role in setting the very name and definition of hysteroliths--their designation for some particularly salient features of female anatomy and their de******ion, by Pliny himself, in terms of three basic dichotomies that build the framework of our mental architecture--then some equally important theatrical idols (that is, constraints imposed by older, traditional systems of thought) defined the central debate that established the course of seventeenth-century paleontology but then pervaded the century: What are fossils?
The view of mechanism and causality that we call modern science answers this question without any ambiguity: Fossils look like organisms in all their complex details, and we find them in rocks that formed in environments where modern relatives of these creatures now live. Therefore, fossils are remains of ancient organisms. This commonsense view had developed in ancient Greek times and never lost status as an available hypothesis. But the domain of seventeenth-century thought--the world that Bacon challenged and that modern science would eventually supplant--included other alternatives that may seem risible today but that made eminent sense under other constructions of natural reality.
Bacon called these alternative world views idols of the theater, or impediments set by outmoded systems of thought. Among the theatrical idols of seventeenth-century life, none was held in higher esteem among students of fossils than the Neoplatonic construction of nature as a static and eternal set of symbolic correspondences that reveal the wisdom and harmonious order of creating forces and that humans might exploit for medical and spiritual benefit. A network of formal relationships (not direct causal connections but symbolic resemblances in essential properties) pervaded the three kingdoms of nature animal, vegetable, and mineral--placing any object of one kingdom into meaningful correspondence with counterparts in each of the other two realms. If we could specify and understand this network, we might hold the key to nature's construction and meaning.
Within this Neoplatonic framework, a close resemblance between a petrified "fish" enclosed within a rock and a trout swimming in a stream does not identify the stony version as a genuine former organism of flesh and blood but suggests instead that plastic forces within the mineral kingdom can generate this archetypal form within a rock just as organic forces of another kingdom can grow a trout from an egg. Similarly, if various stones look like parts of the human body, then perhaps we can identify the mineral forces that resonate in maximal sympathy with the sources of our own animate being. Moreover, according to a theory of medicine now regarded as kooky and magical but once perfectly respectable in a Neoplatonic framework, if we could identify the vegetable and mineral counterparts of human organs, then we might derive cures by potentiating our ailing animal versions with the proper sympathies of other realms, for every part in the microcosm of the human body must vibrate in harmony with a designated counterpart in the macrocosm of Earth, the central body of the universe. If the ingested powder of a pulverized "foot stone" could soothe the pains of gout, then hysteroliths might also alleviate sexual disorders.
The availability of this alternative view, based on the theatrical idol of Neoplatonism, set the primary context for seventeenth-century discussions about hysteroliths. Scholars could hardly ask "What animal molds these fossils?" when they remained stymied by the logically prior and much more important question "Are hysteroliths remains of organisms or products of the mineral kingdom?" This framework then implied another primary question--also posed as a dichotomy (and thus illustrating the continuing intrusion of tribal idols as well)--among supporters of an inorganic origin for hysteroliths: If vulva stones originate within the mineral kingdom, does their resemblance to female genitalia reveal a deep harmony in nature, or does the similarity arise by accident and therefore embody no meaning, a mode of origin that scholars of the time called lusus naturae, "a game or sport of nature"?
In examples of these two views from an unfamiliar age, Olaeus Worm, supporting the first opinion, spoke of a meaningful correspondence (in the textural commentary to his first pictorial representation of hysteroliths in 1665), although he attributed the opinion to someone else, perhaps to allay any suspicion of partisanship:
These specimens were sent to me by the most learned Dr. J. D. Horst, the archiater [chief physician] to the most illustrious Landgrave of Darmstadt.... Dr. Horst states the following about the strength of these objects: these stones are, without doubt, useful in treating any loosening or constriction of the womb in females. And I think it not silly to believe, especially given the form of these objects [I assume that he refers here to hysteroliths that resemble female parts on one side and male features on the other], that, if worn suspended around the neck, they will give strength to people experiencing problems with virility, either through fear or weakness, thus promoting the interests of Venus in both sexes (Venerem in utroque sexu promovere).
But Worm's enthusiasm did not generate universal approbation among scholars who considered an origin for hysteroliths within the mineral kingdom. Anselm de Boot, in the 1644 French translation of his popular compendium on fossils (in the broad sense of anything found underground), writes laconically, "Elles n'ont aucone usage que je scache" ("They have no use that I know").
By the time that J.C. Kundmann--who wrote in vernacular German and lived in Bratislava, relatively isolated from the "happening" centers of European intellectual life--presented the last serious defense for the inorganic theory of fossils in 1737, the comfortable rug of Neoplatonism had already been snatched away by time. (The great Jesuit scholar Athanasius Kircher had written the last major defense of Neoplatonism in paleontology in 1664, in his Mundus subterraneus, or "Underground World.") Kundmann therefore enjoyed little intellectual maneuvering room beyond a statement that the resemblances to female genitalia could only be accidental--for after all, he argued, a slit in a round rock can arise by many mechanical routes. In a long chapter devoted to hysteroliths, Kundmann allowed that these fossils might be internal molds of shells and even admitted that some examples described by others might be so formed. But he defends an inorganic origin for his own specimens because he finds no evidence of any surrounding shell material or form--"an excellent argument that these stones have nothing to do with clamshells, and must be considered as lapides sui generis" (figured stones that arise by their own generation: a signature phase used by supporters of an inorganic origin for fossils).
3. Idols of the Marketplace in the Eighteenth Century: Reordering the Language of Classification to Potentiate the Correct Answer. As stated above, the inorganic theory lost its best potential rationale when the late-seventeenth-century triumph of modern scientific styles of thinking (the movement of Newton's generation that historians of science call the scientific revolution) doomed Neoplatonism as an acceptable mode of explanation. In this new eighteenth-century context, with the organic theory of fossils victorious by default, a clear path should have opened toward a proper interpretation of hysteroliths.
But Bacon, in his most insightful argument of all, had recognized that even when old theories (idols of the theater) die and when deep biases of human nature (idols of the tribe) can be recognized and discounted, we may still be impeded by the language we use and the pictures we draw--idols of the marketplace, where people gather to converse. Indeed, in eighteenth-century paleontology, the accepted language of de******ion and the traditional schemes of classification (often passively passed on from a former Neoplatonic heritage without recognition of the biases thus imposed) established major and final barriers to solving the old problem of the nature of hysteroliths.
At the most fundamental level, remains of organisms had finally been separated as a category from other "things in rocks" that happened to look like parts or products of the animal and vegetable kingdom. But this newly restricted category received no recognized name, for the word "fossil" still covered everything found underground (and would continue to do so until the early nineteenth century). Scholars proposed several solutions--for example, calling organic remains "extraneous fossils" because they entered the mineral kingdom from other realms, while designating rocks and minerals as "intrinsic fossils"--but no consensus developed during the eighteenth century. In 1804 the British amateur paleontologist James Parkinson (a physician in his day job, and the man who gave his name to Parkinson's disease), recognizing the power of Bacon's idols of the marketplace, deplored this linguistic impediment, arguing that classes without names could not be properly explained or even conceptualized:
But when the discovery was made, that most of these figured stones were remains of subjects of the vegetable and animal kingdoms, these modes of expression were found insufficient; and, whilst endeavouring to find appropriate terms, a considerable difficulty arose; language not possessing a sign to represent that idea, which the mind of man had not till now conceived.
The retention of older categories of classification imposed an even greater linguistic restriction. For example, so long as some paleontologists continued to use such general categories as lapides idiomorphoi (figured stones), true organic remains would never be properly distinguished from accidental resemblances (a concretion recalling an owl's head, for example, or an agate displaying in its color banding a rough picture of Jesus dying on the cross, to cite two actual cases widely discussed by eighteenth-century scholars). And absent such a separation, and a clear assignment of hysteroliths to the animal kingdom, why should anyone favor the hypothesis of brachiopod molds, when the very name "vulva stone" suggested a primary residence in the category of accidents--for no one had ever argued that hysteroliths could be actual fossilized remains of detached parts of female bodies.
As a pictorial example, consider the taxonomic placement of hysteroliths in a 1755 treatise by the French natural historian Dezallier d'Argenville. He draws his true hysterolith (A in the figure at left) right next to slits in rocks that arose for other reasons (B and 3) and, more importantly, beneath a stalactite (1) that happens to look like a penis with two appended testicles. Now we know that the stalactite originated from dripping calcite in a cave, so we recognize this unusual resemblance as accidental. But if hysteroliths really belong in the same taxonomic category, why should we regard them as formed in any fundamentally different way?
When these idols of the marketplace finally receded, and hysteroliths joined other remains of plants and animals in an exclusive category of organic remains--and when the name "hysterolith" itself, as a vestige of a different view that emphasized accidental resemblance over actual mode of origin, faded from use--these objects could be seen and judged in a proper light for potential resolution.
Even then, the correct consensus did not burst forth all at once but developed more slowly and through several stages, as scientists, now finally on the right track, moved toward a solution by answering a series of questions--all dichotomously framed, once again--that eventually reached the correct solution by successive restriction and convergence.
First, are hysteroliths molds of an organism, or are they actual petrified parts or wholes? Some proposals in the second category now seem far-fetched--for example, C.N. Lang's in 1708 on hysteroliths as fossilized sea anemones of the coral phylum (colonies of some species do grow with a large slit on top), or M. Barrere's in 1746 on cunnulites (as he called them, with an obvious etymology not suitable for citation in a family publication) as end pieces of the long bones (femora and humeri) in juvenile vertebrates, before these termini fuse with the main shafts in adulthood. But at least paleontologists now operated within a consensus that recognized hysteroliths as remains of organisms.
Second, are hysteroliths the molds of plants or of animals, with nuts and clams as major contenders in each kingdom (with a quick and decisive victory for the animals in this case)? Third, are hysteroliths the internal molds of clams or of brachiopods? This is a debate that now, at the very end of the story, really could be solved by something close to pure observation, for consensus had finally been reached on what questions to ask and how they might be answered. Once enough interiors of brachiopod shells had been examined (not so easy, because almost all brachiopod fossils expose the outside of the shell, while few living brachiopods had been discovered, for they live mostly in deep waters or in dark crevices within shallower seas), the answer could not be long delayed.
We may close this happy tale of virtue (for both sexes) and knowledge triumphant by citing words and pictures from two of the most celebrated intellectuals of the eighteenth century. In 1773 Elie Bertrand published a classification of fossils commissioned by Voltaire himself as a guide for arranging collections. His preface, addressed to Voltaire, defends mode of origin as the best criterion for a proper classification--a good epitome for the central theme of this essay. Turning specifically to hysteroliths, Bertrand advises his patron:
There is almost no shell, which does not form internal molds, sometimes with the shell still covering the mold, but often with only the mold preserved, though this mold will display all the interior marks of the shell that has been destroyed. This is the situation encountered in hysteroliths, for example, whose origin has been debated for so long. They are the internal molds of...terebratulids [a group of brachiopods]. (Author's translation)
But if a good picture can balance thousands of words, consider the elegant statement made by Linnaeus himself in the catalog of Count C. G. Tessin's collection, published in 1753. The hysteroliths (see figure, right), depicted with both their male and female resemblances (2,A-D), stand next to other brachiopod molds that do not resemble human genitalia (1,A and B)--thus establishing the overall category by zoological affinity rather than by external appearance. In numbers 3-6, Linnaeus seals his case by drawing the fossilized shells of related brachiopods--two pictures to guide and establish a transition from the lost and superseded world of Dezallier d'Argenville's theory of meaning by accidental resemblance to distant objects of other domains, to Linnaeus's modern classification by physical origin rather than superficial appearance.
Bacon's idols can help or harm us along these difficult and perilous paths to the accurate, factual knowledge of nature. Idols of the tribe may lie deep within the structure of human nature, but we should also thank our evolutionary constitution for another ineradicable trait of mind that will keep us going and questioning until we break through these constraining idols--our drive to ask and to know. We cannot look at the sky and not wonder why we see blue. We cannot observe that lightning kills good and bad people alike without demanding to know why. The first question can be answered; the second cannot, at least in the terms that prompt our demands. But we cannot stop asking.
Let me close by tying the sequential themes of this essay together with a story that unites Bacon (the anchor of the first part) with Pliny (the progenitor of the second part) in their common commitment to this liberating compulsion to ask and know. Pliny died because he could not forego a unique opportunity to learn something about the natural world--as he ventured too close to the noxious fumes of Vesuvius when he needed to observe a volcanic eruption more closely. Bacon died, albeit less dramatically, in the same noble cause and manner when he devised an experiment one cold day to determine whether snow could retard putrefaction. He stopped his carriage, bought a hen from a poultryman, and stuffed it with snow. The experiment worked, but the doctor died (not the patient this time, for the hen had expired before the procedure began!), as Bacon developed a cold that progressed to bronchitis, pneumonia, and death. He wrote a touching last letter (also quoted in a footnote to last month's essay) that establishes an explicit connection with Pliny: "I was likely to have the fortune of Caius Plinius the elder, who lost his life by trying an experiment about the burning of the mountain Vesuvius: for I was also desirous to try an experiment or two, touching on the conversion and induration of bodies. As for the experiment itself, it succeeded excellently well, but..."
Tribal idols may surround us, but our obsessively stubborn tribal need to ask and know can also push us through, as we follow Jesus' dictum that the truth will make us free. But we must also remember that Jesus then declined to answer Pilate's question: "What is truth?" Perhaps he understood that the idols conspire within us to convert this apparently simple inquiry into the most difficult of all questions. But, then, Jesus also knew, from the core of his being (in the conventional Christian interpretation), that human nature features an indivisible mixture of earthy constraint and (metaphorically, at least) heavenly possibilities for liberation by knowledge--a paradox that virtually defines both the fascination and frustration of human existence. We needed two hundred years of debate and discovery to turn a vulva stone into a brachiopod, but the same process has also stretched our understanding out to distant galaxies and back to the big bang.
A shift in paradigms was necessary before scientists could view these "male and female vulva stones" as internal casts of brachiopod shells from Devonian seas.
A bucardite (bull's heart)--actually the internal mold of paired clamshells--as published by Olaeus Worm in 1665.
S (BLACK & WHITE): Hysteroliths, or womb stones, were first illustrated by Olaeus Worm in 1665. The "female" side is at left, the "male" at right.
S (BLACK & WHITE): In 1755, Dezallier d'Argenville pictured hysteroliths along with a phallic stalactite.
S (BLACK & WHITE): Linnaeus illustrated hysteroliths along with other brachiopods in 1753.
By Stephen Jay Gould
Stephen Jay Gould teaches biology, geology, and the history of science at Harvard University. He is also the Frederick P. Rose Honorary Curator in Invertebrates at the American Museum of Natural History.