The Broken Circle
By Gunnar Broberg
The word "quantitative" applies to natural history during the second half of the 18th century in two distinct but related ways: as characteristic of the object and of the method of study. As for object, the sheer number of known and estimated forms forced new approaches to the storage and retrieval of information; as for method, these new approaches were instrumentalist and, in the dominant system of Linnæus, mathematical. These features—the overwhelming flow of information and the determination to inventory and survey it for useful purposes—characterize much of the learned activity of the late Enlightenment. In what follows, I first bring Ernst Cassirer's opposition between l'esprit de système and l'esprit systématique to bear, and indicate the scope of the problem of order faced by the encyclopedists of the Enlightenment. I then turn to natural history, reporting the inflation of information and some of the problems of keeping it together. Finally, I look at the paradoxes of natural history at the turn of the century.
Encyclopedism and Order
The classificatory project of 18th-century natural history runs parallel to and was in many ways inspired by the development of the encyclopedic enterprise of the same period. Natural historians and encyclopedists shared similar ambitions for totality, coherence, and order. Both camps had to ask the same questions: How much is there in the world to know? Is it proper to measure all the riches of creation? If so, by what "method" should they be described? Is there a correspondence between what we can know and the fundamental nature of things? Parallel to the rapid increase of information
came the epistemological shake-up of the early Enlightenment. Natural history as well as general encyclopedism moved from the finite world of the baroque to the infinite world of modern times. If "encyclopedia" means "the circle of knowledge," the circle was broken during the latter part of the 18th century. Natural history opened out similarly.
In following this development we shall find it useful to adopt a distinction d'Alembert employed in his introduction to La grande encyclopédie . By esprit de système he meant the old a priori physics connected with scholasticism, rationalism, and deduction, the sort of thing that Christian von Wolff did in the first half of the 18th century.Esprit systématique was connected with experiments, empiricist ideals, and a readiness to go down the toilsome path from the Lockean world; travelers on this journey had to accept a demarcation between what we can know and what we cannot know, between physics and metaphysics, and to try not to mingle both sides. But that is what often happened. As Cassirer wrote in The philosophy of Enlightenment : "This difference in mode of thinking [between esprit de système and esprit systématique ] does not mean a radical transformation, it amounts merely to a shifting of emphasis. This emphasis is constantly moving from the general to the particular, from principles to phenomena. But the basic assumptions remain. . ., the self-confidence of reason is nowhere shaken. The rationalistic postulate of uniformity dominates the mind of this age."
The 18th century manifested its rationalism in encyclopedias. Natural history helped to determine their structure. The Linnæan encyclopedia had one of its roots in the religious idea of Creation as the Book of Nature opened to the naturalist-reader. The same ambition to take possession of what had been discovered, indeed conquered, characterized both the Systema naturae and the great French
Encyclopédie . It was not mere coincidence that d'Alembert's and Diderot's great work began at the same time that Georges Louis Buffon's Histoire naturelle and the geodetic survey of France started. In his Discours préliminaire , d'Alembert alluded—and most appropriately—to the new success of natural history. Each side could profit from the other. Linnæan natural history, with its clear structure, universal language, and simplicity, made a good model for encyclopedias. Its rationality and practicality gave it entrée everywhere.
According to Zedler's magnificent Grosses vollständiges Universal-Lexicon aller Wissenschaften und Künste (1732–54), an encyclopedia is "a total idea of all sciences, which the ancients brought together so as to show the relationship they have to one another." Zedler settled for something less. Both he and Ephraim Chambers, the author of the Cyclopedia (1728), arranged their works not systematically but alphabetically, though, to be sure, not without long discussions about the systematic aspect: "It may be even said, that if the system be an improvement upon the Dictionary, the Dictionary is some advantage to the System; and that this is perhaps the only way wherein the whole circle, or body of knowledge, with all its parts and dependencies, can well be delivered." Chambers, who was influenced by Locke and Newton, went on to explain the perfection that characterizes a classical work in contrast to a modern one. The classic had so little to compare itself to that it could devote all its attention to order and its own perfection, whereas the latter—"since experiments are endless"—will never reach so far. "To have philosophy complete, we should have the order, precision and distinctness of the old; and the matter and copia of the new." Chambers opposed order to abundance of material.
The opposition Chambers developed was connected with the decline of rationalistic systems of sciences in the Leibniz-Wolff
tradition, which were especially important in Germany from 1720 to 1765. These often extremely elaborate maps of knowledge lost much of their appeal when examined in the light of English empiricist and French sensualistic epistemology, more precisely the French Encyclopédie and later Kant's criticism. The Encyclopédie has often been taken as the starting point for a new concept of knowledge because of its antimetaphysics, its updated information, its optimism, its democratic call for action, and many more things, including its empiricism.
The Encyclopédie was a joint adventure with many collaborators and two principal editors, Diderot and d'Alembert, who did not agree about everything. D'Alembert's famous Discours préliminaire stressed the "order and connection of human knowledge," the inner order and harmony of the sciences, and the possibility of making a uniform system of encyclopedic knowledge. It was not clear, however, how he supposed the tree of knowledge to grow—did logical division or historical development control the branching? His ideals were those of a geometer, believing in a regular universe and operating with axioms and principles. "If somebody could survey the whole universe from one standpoint, it would be seen as consisting of one single fact and one single truth." Alphabetical order does not necessarily invalidate coherence, since cross-references could link the various subject matters from a synthetic point of view. How well these combinations in the end corresponded to the tree of knowledge was problematic.
Diderot's article "Encyclopédie" (1755) gave a truer picture of the purposes of the Encyclopédie . It responded to accusations that the first volumes did not have the coherence promised in d'Alembert's essay: "It is impossible to improve the arbitrariness of this great original profusion. The universe presents us only with individual things, infinite in number and with almost no fixed and determined division [among them]; none of them can be called the first or the last; everything is connected to everything else by insensible gradations." Later
Diderot insisted on the value of irregular articles. "The formation of an encyclopedia is like the foundation of a great city." He compared encyclopedic order with a machine, the parts of which fit together, but which can also be assembled in a completely new way. Rather than being the organized accumulation of the total stock of human knowledge, the cross-referenced Encyclopédie would be an open-ended conversation among members of a cité scientifique .
Diderot's dynamism would become even more pointed in the Rève d'Alembert , in which he defended poetry against geometry. That did not mean total hostility toward all "systems," only metaphysical and deductive ones; acceptable systems should act as heuristic devices and hypotheses and as pedagogical tools. When Diderot defended this openness in contrast to closed systems, he also defended the alphabetical arrangement, which predominated thereafter. This arrangement represented an important step toward secularization of knowledge and agnosticism toward taxonomies of knowledge. To quote a recent interpretation: "As the zero degree of taxonomy, alphabetical order authorizes all reading strategies; in this respect it could be considered an emblem of the Enlightenment."
The encyclopedic business thrived on this tension between knowledge and information. The first edition of Encyclopedia Britannica (1768–71) was more weighted toward information, whereas the success of the Brockhaus Conversationslexicon provoked charges of superficiality. Hegel used the same word as Kant did for natural history works, Aggregaten, to describe the state of contemporary
encyclopedias. To Hegel, an encyclopedia should be a summarized introduction to scientific knowledge. An heroic attempt to combine these different traditions, literally identified with the heritage from Francis Bacon and Plato, is found in the "General introduction" to the Encyclopedia metropolitana (1817). The objective is no less than a reconstruction of "the circle of knowledge in its harmony" to provide that "unity of design and of elucidation, the want of which we have most deeply felt in other works of similar kind, where the desired information is divided into innumerable fragments scattered over many volumes, like a mirror broken on the ground, presenting instead of one, a thousand images, but none entire." But the future belonged to fragments and to Brockhaus's Aggregaten .
Whatever its organization, an encyclopedia required supplements to stay current. A popular work could be updated, commented on, and augmented; but in principle an encyclopedia should stand unaltered. The editors of the Encyclopédie failed in their initial plans to translate Chambers' Cyclopedia . Too much had to be altered or added. A two-volume Supplement to Chambers' work was published in London in 1753. About the same time a new series of supplements began to complete the already published sixty-four volumes of Zedler's Lexicon, and Felice's Encyclopédie, ou Dictionaire universel raisoné des connaissances humaines , received six volumes of supplements in 1775–6. Four supplementary volumes completed d'Alembert's and Diderot's great work in 1776–7. This constant adding made an encyclopedia something like a journal. Diderot wrote to the point. "An encyclopedia is a rapid and disinterested exposition of mankind's discoveries in all places, of all types, and in all times, without any judgment about people. Journals are only a passing account of books and authors." Still, the comparison was possible,
and in a sense the encyclopedia and the newspaper were getting closer to one another.
The increase of information that perplexed encyclopedists also vexed lexicographers. In his Plan for an English dictionary (1747), Dr. Johnson declared it to be his purpose to "fix" the language once and for all, because "all change is of itself evil." By the time his Dictionary appeared in 1755, Johnson had shifted his position. He now thought that "fixing" the language was as futile an effort as "embalming" it. In the interim he had put in much hard work to collect words and to define them, work similar to what natural historians tried to do in the species jungle. He too had to deal with the problematic relation between words and things. "I am not yet so lost in lexicography as to forget that words are the daughters of earth, and that things are the sons of heaven." Thus he inclined to accept Locke's criticism of essentialism, although as a lexicographer he could not be happy about the instability of meanings. "Definition is, indeed, not the province of man; everything is set above or below our faculties," he sighed on another occasion. The lexicographer had to make the best of the situation, and describe words, not define them; and so Johnson proceeded.
Emanuel Swedenborg also had something to say about the growing awareness of never-ending knowledge. In an undated note from the middle of the century he wrote: "I was allowed to enter a library where there was a great number of books. . . . In the inner parts of still more libraries were books written by adherents of the old churches and still farther were books from the oldest. . . . The libraries had many departments according to the training of the students. There were also many other libraries in heaven, but not public ones. Further on there were still more libraries likewise divided into
departments. They were as many as there are research areas." We meet the famous spiritualist and one-time scientist, the inspiration of Borges' story of the libraries of Babel and of Eco's monastery; we recognize the principle of plenitude, and also of order. The multitude is overwhelming, but chaotic only to those who have not found—like Swedenborg and his fellow countryman Linnæus—the general patterns of reality.
The relation between order and plenitude is a constant problem in librarianship. A survey of German Sachkatalogen from the 17th to the 19th centuries shows a change from hierarchical systems to alphabetism. Gabriel Naudé, who introduced the concepts of systematic and alphabetic catalogues in the early 1600s, compared a library to an army. Strict order must rule in both. During the second half of the 18th century the Göttingen school of librarianship dominated. Its head, professor of medicine Georg Matthiae, stressed the necessity of arranging the library into "classes" according to a "natural" system. The systematic catalogue should be given priority over an alphabetic one since the coherence of books provides the basis of a scientific arrangement; considerations of size, form, and so on, mark the simple and unscientific librarian. Some disagreed: "Pure arrangement of books by their sciences is almost impossible and by no means necessary. The place a book stands is of no importance." The librarian's main problem was to find room for new books on old shelves; but, like natural historians, librarians wanted to raise their professional status by invoking order, classification, and science. The reverse analogy also held. Linnæus once wrote: "Gardens are like living libraries of plants." The garden and the library shared the same problem: growing knowledge had made systems cumbersome.
The Challenge of Plenitude
The plenitude of being was a constant cause for religious as well as scientific amazement. John Ray's famous The wisdom of God manifested in the works of creation (1691) opens by quoting Psalm 104:24—"How manifold are thy works, O Lord! In wisdom hast thou made them all"—and continues by changing the exclamation into a question. Ray called attention to the number of stars and planets, then calculated the number of animals. His estimate that there are 2,000 insect species in Britain alone, and 20,000 in the whole world, must have seemed very bold at the time, and likewise the figure 40,000 to 45,000 for all plants and animals together. He also discussed the proportions between the number of species, showing that the less perfect genera contain more species than the more perfect, a matter he went on to explain with many insights into the interplay of nature. To him, as to many of his contemporaries, the microscope had proved the plenitude of creation. We should note a typical 17th-century conceit: the greater the number of variations, the greater the glory of Man, since the Lord made them for human pleasure. As Ray put it: "another reason why so many kinds of creatures were made, might be to exercise the contemplative Faculty of Man; which is nothing so much pleas'd as in the variety of objects."
Compare Ray's numbers with the estimates given by Pieter van Musschenbroek half a century later. Following Hermann Boerhaave's lead, Musschenbroek reckoned the number of plant species at 13,000. He allowed 5 insect species to each plant. This made 65,000 insects
and (he guessed) 72,500 species in the entire animal kingdom—or, rather, twice that many, since each animal serves as food for another. Suddenly, the number has reached 145,000, and, again, the figures should be doubled since so little of the earth had been explored. We have in all 291,000 species, magnificent proof of the skill of the creator. Musschenbroek referred to Antony van Leeuwenhoek, to Henry Baker's book on microscopy, and to René Antoine Réaumur's entomology. It may be objected that Musschenbroek, a professor of physics, reasoned too much like a mathematician to win the confidence of the natural historian. Still, both had recourse to physicotheology.
At first, Linnæus probably did not estimate nature's multitude as extravagantly as had Ray. He inherited the task of describing the 6,000 species in Caspar Bauhin's Pinax (1623) from his predecessors, Olof Rudbeck, father and son, who planned to publish pictures of every known plant. (Their project was stopped by the great fire in Uppsala in 1702.) Anyone shouldering such a task would try to keep the numbers down. According to Linnæus, botanists should be able to remember at least all genera. Hence this second Adam, as Albrecht von Haller called him, must have believed it possible to survey nature taxonomically. In his Oratio de telluris habitabilis incremento (1743), he supposed that in the beginning the world was a paradise island containing all species. The only thing that had happened since then was the constant increase of individuals—and land.
The number of new discoveries during the 1740s forced Linnæus to change his mind. He had to fit these novelties into the context of his already published textbooks. The characters of the fresh-water polyps and the corallines, and later different fungi, seemed to contradict the taxonomical borderlines of nature. Critics labeled the
sexual system scholastic and artificial and contrary to the notion of nature's great chain. As an answer, Linnæus sketched an evolutionary hypothesis in Genera plantarum (1764), which also expressed his views about the natural system of plants. The more Linnæus peeked into the secret depths of nature, the more he found intricate connections. He now preferred the concept of mappa naturae over the simple hierarchical arrangement of the scala naturae.
Still more material flooded into Linnæus' study. The Systema naturae expanded from twelve folio pages in the first edition to almost 2,000 pages in the twelfth. He classified some 7,700 plants, 6,200 animals, and 450 mineral species. Altogether Linnæus' nature contained no more than 15,000 species, but that, as he knew, was but a beginning. Systema naturae goes from God to gravel, aiming at nothing less than a complete inventory or encyclopedia of the world. To Linnæus, nature's multitude must have been both a wonderful ongoing revelation and a terrible curse. He must have been one of the greatest optimists of all time. His library, now in the Linnæan Society of London, is filled with volumes of additions scrawled in the margins of his books.
Did Linnæus ever indicate the possible "size" of nature's kingdoms? Perhaps. In the fifth edition of Genera plantarum (1754), he introduced the idea of an alphabet or letters of the botanical language. These 26 letters combined two at a time were to cover all parts of the flower with the help of four "certain and mechanical principles," namely number, position, figure, and relative position. By a combination of these characters, botanists could give a good description of the genera, which in difficult cases should be checked by the concept of "habitus," the over-all impression of the plant. The largest possible number of genera is 26 × 26 × 4 or 2,684. Linnæus' evolutionary hypothesis of 1764 seems to end up in a similar number. At the beginning God created the "natural orders," which Linnæus elsewhere counted as 58. The next level, of the genera, came into existence by "mixing" the orders two by two: 58 × 58 makes 3,364
natural genera. The third step, another multiplication by 58, gives us the number of possible species "mixed" by nature. There is also a fourth step, when "casus" or change mixes the species, which constantly happens and to such an extent that the botanist should not bother about all the resultant "varieties." Thus, the successive unfolding of types is caused by God, nature, and chance. The orders and the genera deserve special study. To keep up with the rest will be almost impossible. Here Linnæus seems to have retreated from his earlier optimism about human possibilities. If his reasoning seems odd, consider this from his fellow Swede Christopher Polhem, the great technical innovator. A descriptive name can be constructed by using letters in a prescribed order. For instance, an initial "p" could mean man, a "b" animal, "k" grass, while vowels might stand for the different senses, "a" for sight, "e" for hearing, "i" for smell. Further letters could indicate medical effects. With this system, Polhem guaranteed 1,406,250 possibilities; "more differences should not exist." If they do, it would be easy to add one or more variables or letters.
Linnæus' critic, Buffon, had to face the same problems. At the outset of his series on birds, he admitted a problem in acquiring all existing species. He and his collaborators worked for twenty years, constantly enlarging the collections of the Cabinet du Roi but never approaching completeness. Still, he could offer three times as many species of birds as were found in the tenth edition of Systema naturae (1758). (These figures depended on species definition and are not strictly comparable.) There are two competing strains in Buffon's writing: his early fascination with individuality in nature and his later encyclopedic ambitions. These tensions are even more obvious in the writings of Linnæus' second major French critic, Michel Adanson. Adanson faulted Linnæus for, among other things, grossly
underestimating the number of species of coquillages in Senegal. We will return to Adanson. Here he exemplifies awareness of nature's tropical abundance, while Buffon represents the contention that this abundance cannot be counted.
Linnæus and Buffon both received credit in an unusually unbiased way in Haller's preface to the German translation of the Histoire naturelle (1750). In view of his old quarrel with Linnæus about who was the better naturalist and who had collected more plants, this sympathetic judgment might seem surprising. It may be explained by the message of the essay, that is, the blessings of hypotheses for the progress of science. "Laws in botany are arbitrary," Haller stated, "but they have done us an unbelievable service. Now we can distinguish ten thousand plants more easily than the Ancients did their six hundred." Linnæus' new theory performed the greatest service. At present, botany was advancing its lead over all sciences. "Not only is it nearest to completion, and has little by little determined the nature of almost all its classes and resemblances; it has [also] spread its laws throughout the entire Kingdom of Nature. Zoologists and mineralogists have received their laws from it and accepted them as the Romans did from the Areopagus." This last allusion is not a poor piece of flattery. Haller certified that botany would soon be finished, that all the work of collecting material and its description would be brought to their happy end. Success was guaranteed by the model he gave for natural history research: just as a land surveyor begins a map by determining some locations without the positions of places in between, the natural historian starts off with an initial sketch, which later knowledge will fill. The analogy is typical for an era of geographical exploration. It hardly implies the notion of an infinite or a dynamic nature, but rather only the hope of completing the process of exploration.
A similar promise of prompt success (if only governments and princes would offer enough financial support) appeared in an article with the upbeat title, "Have we still to hope for a complete system of nature?" The author, entomologist Johan Samuel Schröter, did so hope, provided natural historians adopted his rules. In Schröter's scheme, only one person should be responsible for each major natural group and should be endowed with dictatorial powers to suppress quarrels among naturalists. Schröter held that only a group of specialists in natural history, and not a single person alone, could fulfill the Linnæan task. Other necessary preconditions were "ability, leisure, and money."
The most ambitious attempt of the 18th century to secure exact figures for the contents of the natural world, however, was made by Eberhard Zimmermann in his book, Geographische Geschichte des Menschen und der allgemein vierfüssigen Thiere (1778–83). Zimmermann combined macroscopic information from the explorers with inspiration from the microscopists' overfilled world. As professor of mathematics—he taught Gauss at Braunschweig University—he excelled in calculations about the size of the known world in relation to the number of known animals. These ratios show an impressive knowledge of zoological detail but also have strong similarities with the more unrealistic parts of political arithmetic as well as with Musschenbroek's calculations. Zimmermann vigorously pursued the Linnæan project, and equally vigorously attacked Buffon's "complete ataxia." But Zimmermann's calculations made the works of the Lord too manifold for the grasp of His creatures.
Zimmermann began small, with minerals, whose maximum number he put at 750. The variety of plants is much greater; recent estimates reached to almost 30,000 known species, only a fraction of the total quantity, which Zimmermann by various calculations raised
to 175,000. He showed even more interest in the number of animals. Erxleben, Schreiber, Johann Friedrich Blumenbach, and others had set the quantity of known species at 10,000. Following Roesel von Rosenhoff and Linnæus (Pandora insectorum, 1758), Zimmermann proposed that there must be at least five insect species specialized on each plant species. Immediately we have 175,000 × 5 or 875,000 insect species of which only 51,000 had been described; entomologists had work to do. Nature abounds with parasitic and intestinal worms, with polyzoa and infusoria, and the sea is crammed with life to an extent almost impossible to grasp. "Who can follow the flying fish?" Probably the variety of sea organisms is two or three times that of land organisms. Zimmermann provided for invisible organisms, small and pellucid, on which the insects feed, and also for atmospherical fauna. Bearing all this in mind, he reached seven million species of animals, perhaps more. Then there are the innumerable specimens of each species. In the universe our planet is just a small spot unknown even to the inhabitants of Jupiter. And yet it has such multitude and magnificence! Zimmermann ended his essay with "a paean of thanks" to the Creator, the traditional natural-theological envoi . Following the natural-philosophical tradition as well, he offered calculations of the number of mammals undiscovered in different parts of the world, but despite the obvious interest of these estimates for the history of biogeography we leave them out.
This account of Zimmermann's work sums up several of the features of late Enlightenment natural history. He enthusiastically accepted the Linnæan project of species-hunting. Several times he appealed to princes for support for its completion. He was also intoxicated by the idea of nature's plenitude. As Ray did a century earlier, he compared the plenitude of this world with the plenitude of the universe. But we must note the enormous difference in the numbers they gave. And Zimmermann turned the whole architecture of the chain of being upside down. Whereas Ray (and Linnæus in Oratio , 1743) claimed that the ratios between nature's kingdoms were such
that the lowest—the mineral—was more numerous than the vegetable, the vegetable more than the animal, Zimmermann proudly formulated a different and "remarkable law: the total of types of organized bodies increases with the degree of sensation and life." Throughout Zimmermann supported the idea of the chain of being, but obviously that notion was collapsing—so to speak—under its own weight. Zimmermann's discussion reflected many of the components of 18th-century natural history, but his figures neither fit the Linnæan project nor supported the single-line chain of being. His account did not visibly change the direction of natural history, but it forced two themes to the surface: the dramatic growth of numbers and the pessimistic prospects for complete knowledge.
So much for external problems; the Linnæan system has internal ones as well. It was fundamentally mathematical in a very simple way, based on the numerical principles of the sexual system as well as on zoological taxonomy. The naturalist counted stamens and pistils, teeth and nipples, toes, scales, antennas, everything. Among other advantages, mathematics afforded brevity and exactness. Linnæus was in every respect an economical man, who had to budget both time and space for his enormous undertaking to map the whole natural world. Without the Linnæan reforms the natural historian would not have been successful in surveying nature; with them, however, nature might appear to be one long list of numbers.
It was reasonable to question the validity of the criteria. Buffon did, in his famous criticism of Linnæus in the "Premier discours" of the Histoire naturelle in Buffon (1749). There Buffon argued that species as well as higher taxa are simply constructions of the taxonomist, while nature by contrast only consists of individuals. For Buffon, the counting of stamens and pistils has nothing to do with the true study of nature. He found no room for mathematics in natural history, the more remarkable considering his background in
that discipline. Nor did he use numbers to reason about nature's continuity. Indeed, he did not stress continuity in his writings as strongly as is generally thought. He of course made references to the great chain of being; but he rejected the idea of animal reason and opposed linking human and animal via the ape as a link to man. At bottom, however, what makes Linnæan taxonomy impossible in Buffon's eyes is that the number of natural "groups" must be infinitely great, since the only natural entity is the individual. The only way to treat nature, the only "method" or plan in the Histoire naturelle , is to accept subjectivity and to arrange descriptions according to how we normally get to know the animals.
In many ways Buffon adhered to the observer tradition, as did the master entomologist Réaumur, who advocated a similar concentration on the individual in contrast to more or less complete taxonomic surveys. Since we never will know everything, Réaumur wrote, we should not regret that some thousands of insects do not figure in our inventories. Instead, we should concentrate on the truly interesting wasps and butterflies. Observations rather than coherent systems are what matter.
In another line of attack, Linnæan mathematics was met with more mathematics. Adanson attacked the essentialistic and scholastic elements in Linnæan taxonomy and recommended an overall statistical evaluation of the plant's character, a method appropriate for modern computers. It is uncertain how far he himself used his method. It is not only extremely time consuming, it also stands in strong contrast to his predilection for completeness and universality. Thus Adanson's suggestions, although in many ways interesting, were a dead end in practice. Practical taxonomy could function only in connection with some sort of essentialism, while nominalism seemed to belong more to philosophy.
The philosophical core of these objections and of 18th-century natural history in general was the idea of the great chain of being. In his thematic study, Lovejoy singles out the species problem, the interest in missing links, and the studies of the microscopists, all of which involved philosophical problems such as continuity and causality. By the end of the century, the idea had suffered many changes. Lovejoy emphasizes what he calls the temporalization of the chain, brought about by the study of fossils. More might well have been said about continuity . In general, both philosophers and natural historians adhered to the Cartesian-Leibnizian idea of continuity without any leaps or bounds. Action by contact keeps the world together and makes it go around. The Newtonian model of a void universe operating by distant forces did not appeal to natural historians. If there is continuity along the whole chain, then it should be possible to use the same classificatory devices and characters to judge all organisms. But, as Charles Bonnet objected, humans lack the right perspective and must satisfy themselves with "classifying classes," with specializing within fairly broad limits. Linnæus could stretch his scheme through botany only with difficulty—the sexual system was hardly useful for the cryptogams—and new principles were invoked for the other kingdoms of nature. Natural historians could see only fragments of the great chain before it twisted or disappeared from sight.
The related problem of plenitude , so beautifully demonstrated by the observations of the microscopists, also meant continuity along the
chain. Its main impact on classification, however, was the implication that God created an unlimited number of individuals rather than "types" or species. The vast numbers that came into being through the laws of generation were studied by Leeuwenhoek and other animal demographers. How to impose limits on this continuity? The question was similar to Zeno's paradox and, if taken seriously, could have led to taxonomy's suicide. The 18th-century natural historian had to deny the physicotheological premises that underpinned his work. To be sure, some very straightforward observations could strengthen him in his denial. As Voltaire wondered shrewdly, why is there no link between animals with two feet and with four? Johann Hermann, in his admirable Tabula affinitatum animalium (1783) (affinity had become the new catchword for genetic, evolutionary, or taxonomic relationship), emphasized symmetry in the animal world. To him, the chain was not linear but rather like a net with many intermediary and vacant steps. The number of possible types between two species of bug became almost impossible to estimate. Working with only ten variables, he found 10,172,640 possible varieties. Where, then, is the species limit? His conclusion seems to be that, apart from the possibility of an innumerable quantity of species on other planets, about which we know nothing, the Creator must have condensed his unlimited multiplying ability into a limited number of multifaceted species. As a solution of the plenitude dilemma,
Hermann's suggestions seemed good enough. But they were purely defensive and conjectural.
Kant's criticism of Linnæan natural history also deals with the problems of continuity and plenitude. Either we work from logical entities as Linnæus did in Systema naturae , or we work with categories like time and space, that is, with Naturbeschreibung or Naturgeschichte based on geography. The Linnæan method did not attend to geographical dispersion. Kant sharpened his view: "The systems of Nature so far proposed should more correctly be called Aggregates of Nature; for a system presupposes the idea of the whole , from which the multiplicity of things can be derived. Really we have no Systema naturae . In our present systems, things are just placed together." This criticism, delivered in a lecture in 1756, was sooner or later bound to affect the ethos of natural history.
We conclude this section with two examples of pessimism, or rather modesty, on the part of late 18th-century epistemologists. The Swedish-Finnish chemist Jacob Gadolin observed that scholars stumble and fumble through the unknown regions of knowledge hoping to find a chain like the Linnæan method to follow. "If every country had its Linnæus, there would be no end of discoveries since Nature is an unfathomable treasure." So far optimism—but as Adam after the Fall was to experience, "the more we open our eyes the more we see that we are naked." Gadolin combined epistemological skepticism with traditional biblical pessimism. Again in a combination of religion and chemistry, Joseph Priestley confessed that for himself he found it impossible "to produce a work that shall be anything like complete ." "In completing one discovery we never fail to get an imperfect knowledge of others, of which we could have no idea before; so we cannot solve one doubt without creating several new ones." "The greater is the circle of light, the greater is the boundary
of the darkness by which it is confined." The awareness of this truth is the other side of the belief in progress.
The Broken Circle
The success of natural history was overwhelming. With well-founded enthusiasm, Sir James Edward Smith in 1788 pushed to inaugurate a new society entirely devoted to this study, which came to life as the Linnæan Society of London. He wrote: "He who determines with certainty a single species of the minutest moss or meanest insect, adds so far to the genral stock of human knowledge, which is more than can be said of many a celebrated name." Smith had good reasons for thinking that his initiative would be well received, since more and more scholars worked in naming and surveying the living world. Linnæan natural history had conquered rival systems and spread into other areas as well. A common, international scientific language thus developed. Internationalism in botany was promoted further by trade in seeds and dried specimens and by the travels of natural historians. Traveling scientists, Linnæan apostles, Blumenbachian headhunters, the Cook company, explorers, adventurers, artists, collectors, all brought home a rich harvest from the field.
Natural history became interesting to the general public also as a part of a new aesthetic appreciation of nature. The growth of gardens and museums demonstrated the institutional strength of natural history. Curators naturally wanted to increase the size of their holdings. Next to salaries, the botanical garden and the library made heaviest demands on university budgets. Visits to famous gardens were
mandatory for the traveler. At the end of the 18th century, Kew Garden had grown to an important promoter of the new tastes in England. To Kew and to the President of the Royal Society, Joseph Banks, came endless material from the colonies. Museums, no longer chambers of curiosities but institutions serving the scientific public, were entering the modern era. In France the Jardin du Roi was reorganized after the Revolution into the Muséum d'Histoire Naturelle according to a modified Linnæan plan.
Among the modifications was abandonment of the hope of a complete inventory of nature. Rather than showing the full divine order, the naturalist collectors wanted to outdo competitors in the size of their herbaria. The competitive element in collecting became increasingly obvious, but it was a race without a finish line. When Carl Peter Thunberg, successor to Linnaeus at Uppsala, had his Botanicum built around 1800, his architect provided herbarium space for only 15,000 specimens. Soon the windows in the beautiful main hall would be blocked with the cases of specimens that marked Thunberg's proficiency in the collecting game. In writing he devoted himself to mere description of small units and did not try to put together the big jigsaw puzzle. Thunberg's admirable industry is obvious from his series of dissertations on Nova plantarum genera (fifteen parts) and his Museum naturalium academiae upsaliensis (twenty-nine parts including appendices). His colleague, the entomologist Schönherr, wrote sixteen volumes totaling 5,000 pages on the insect-group cucurlionides . The dream for completeness survived only in completeness in detail. Its form could be labeled "descriptionism," a pure registration of facts.
In the early 19th century, probably only Robert Brown could handle the whole of botany. The last person able to treat all of nature was Alexander von Humboldt, who discovered several hundred plant species along the slopes of Chimborazzo in a few months (1800). The mass of little details struck some people as ridiculous. The philosopher Lichtenberg predicted the advent of "a Linnaeus of sand." Coleridge complained that despite all the work by the botanists there was "little more than an enormous nomenclature, a huge catalogue, bien arrangé , yearly and monthly augmented in various editions, each with its own scheme of technical memory and its own conveniences of references!"
The new situation called forth a variety of means of publication: a growing number of sumptuous books for the connoisseur, textbooks for the tyros, handbooks for the collectors, journals for specialists. It also produced a number of bibliographies by Haller, by Boehmer, by
Jonas Dryander (on Bank's library), by Joseph Reuss, and so on. A new genre arose, the natural-history dictionary . With its alphabetical arrangement, it aped the encyclopedias: facts, in the Lockean sense, would speak for themselves. Considering their number, these dictionaries must have meant good business for the publishers; considering the size of some of them, they did have something to summarize. They are a proof of the success and the failure of 18th-century natural history.
The compilers of dictionaries had two banks to rob: Systema naturae and Buffon's Histoire naturelle , changed into smaller coin and arranged alphabetically. The reader got Linnaeus' exactness and Buffon's fine writing, both science and literature, in such extravagant works as Houttyun's Natuurkyke historie of uitvoerige beschryving der dieren, planten en mineralen , published in thirty-seven volumes (1761–85), and Valmont de Bomare's Dictionaire raisoné universel d'histoire naturelle (1760– ), in fifteen volumes, at least five editions, and a Danish translation (Den almindelige naturhistorie i form af et dictionaire (1767– ). There was also Friedrich Heinrich Martini's Allgemeine Geschichte der Natur in alfabetischer Ordnung (1774– ), which built on Bomare's Dictionaire and invited its readers to participate in making a new edition by filling out pages left blank for the purpose. The new edition would not be complete, of course; in natural history, Martini said, "complete is a harmonious sound without meaning." There were still more dictionaries: the anonymous Manuel du naturaliste (Paris, 1770); W.F. Martyn's A new dictionary of natural history ; Philip Miller's very handsome The gardener's and botanist's dictionary (1731, 8th edition 1768); and Lamarck's botanical chunk of the Encyclopédie méthodique . A somewhat earlier, similar trend has been noted in geography.
Both Linnaeus and Adanson had considered the possibility of making dictionaries. Through his patron Carl Gustav Tessin, Linnaeus had the help of a copyist to compile a Dictionnaire portatif d'histoire
naturelle . He began in 1757, but abandoned the project two or three years later. It fell victim to his fear that nothing can be omitted. Nothing, in any event, is left of the manuscript. In a Memorial printed in 1775, Adanson summarized what he had accomplished so far—the description of 300 species of mammals, 2,000 of birds, and so on, in all some 17,000 animals, 10,000 plants, and 8,000 to 10,000 minerals. He proposed grand and encyclopedic ventures, a new nomenclature, a universal language, a plan to cover all natural history in three "orbes," the first to contain 40,000 species. Nothing, however, came of these plans; and to cope with economic realities he had to work in the dictionary business. To the Supplément à l'Encyclopédie Adanson contributed about 450 articles, and among his huge piles of manuscripts there is much material intended for alphabetical publication. In their unsuccessful way both Adanson and Linnaeus tried to balance two interests: scientific order and communicable information.
There were other strategies to make natural history scientifically meaningful. Georg Forster returning from the Cook expedition wanted to combine Linnæan formalism and Buffon's individualism, as in his famous monograph on the breadfruit tree. Robinet preferred to concentrate not on the species level but on the type. That was also the way chosen by the idealistic morphologists, by Goethe, Etienne Geoffroy Saint-Hilaire, and Sir Richard Owen, and in Sweden by the mycologist Elias Magnus Fries and the algologist Agardh. Or one could adjust the size of taxonomic groups to make them easier to handle. That seems to have been the reason why Alphonse-Laurent de Jussieu recognized one hundred families of plants, none of which had more than one hundred genera. Then
there was Humboldtian science, which took not the species or genus as subject of study but the plant community as such.
The widening scope of the natural history project split it into such specialties as ornithology, entomology, and mycology. The new public for natural history, professors as well as amateurs, wanted information to suit diversified tastes. Thus, as a result of the widening fragmentation of the subject and the dissolution of the chain of being, a new science was invented. "Biology" was inaugurated in the very year 1800 by Jean Baptiste Lamarck, a critic of the concept of the great chain but also one of the most prominent pursuers of the natural history project.
Finally, we must note a change of metaphors. Both natural history and encyclopedism had experienced the increase of quantity , of boundless, unmeasurable information. The encyclopedic enterprise, aiming at order, totality, and coherence, had exchanged the esprit systématique for the esprit de système . In natural history, epistemological criticism and awareness of nature's richness had made the great chain of being succumb to its own weight. The metaphors of "chain" and "scale," both very popular during the 18th century, gave way to metaphors less apt for classification, such as "map" or "net," used by, among others, Linnaeus, Haller, and Hermann. The geographical imagery recurs in Adanson's "orbe." In a similar manner, d'Alembert used the older metaphors "circle of knowledge" and "tree" in elucidating the concept of encyclopedia, while Diderot preferred "growing city" and "machine." The critics (Kant, Hegel, Törneros) spoke of the modern encyclopedia as an "aggregate" or a "grocery store." There is a clear progression from symbols appropriate to a traditional classification to symbols suited for an open-ended collection. The systematic "encyclopedia" in the old sense of "whole circle of knowledge" was breaking up. This broken circle is one aspect of the
critical work of the Enlightenment. It might be possible to argue that such a shift reflects a general development during the second half of the century from a "geometrical" to an "arithmetical" mentality, when systems and stable structures mattered less than quick, irregular information.