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Home , Jan Swammerdam, Louis de Jaucourt, Natural History, Natural History (Pliny), On Plants, Systema Naturae

18th Century

The Enlightenment, Linnaeus, and Buffon

Waseda University, SILS, History of Modern Earth and Life The European Enlightenment

d’Alembert (1717–1783): “Our century is called … the century of par excellence… The discovery and application of a new method of philosophizing, the kind of enthusiasm which accompanies discoveries, a certain exaltation of ideas, which the spectacle of the universe produces in us – all these causes have brought about a lively fermentation of minds, spreading through in all directions like a river which has burst its dams.”

When (1724–1804) was asked if he believed he and his contemporaries were living in an enlightened age, replied: “No, we are living in an .”

18th Century Natural History 1 / 40 and nature

The Enlightenment lionized the mathematical sciences – especially as practice by Newton, Leibniz and those who followed their model – and placed a special emphasis on reason. It was widely believed that the model of rational could be used to improve all of the sciences and society Enlightenment thinkers and believed that laws could be found in many areas of the natural and social world, and that finding and understanding these laws was the true goal of philosophy. They placed a high value on studies of the natural world. An important result of this approach was that it made natural history – studies of and , of rocks and geological formations – into a popular topic among the upper classes.

18th Century Natural History 2 / 40 Dictionnaire raisonné de sciences, des et des métiers

Encyclopédie ou Dictionnaire Raisonné de Sciences, des Arts et des Métiers

First published 1751–1766, with later supplements and many translations, etc. Edited by Diderot and to a lesser extent d’Alembert. 35 volumes, 71,818 articles, 3,129 illustrations. The contributors were many of the most important scholars, thinkers and scientists in France. (Louis de Jaucourt wrote 17,266 articles.)

18th Century Natural History 3 / 40 The Goal of l’Encyclopédie

Progress was one of the fundamental ideals of the Enlightenment, insofar as it assumed the perfectibility of society and of humankind through a rational, scientific improvement of material .

Diderot, l’Encyclopédie, Preface (1751) “… to collect all knowledge scattered over the face of the earth, to present its general outlines and structures to the men with whom we live, and to transmit this to those who will come after us, so that the work of the past centuries may be useful to the following centuries, that our children, by becoming more educated, may at the same time become more virtuous and happier, and that we may not die without having deserved well of the human race.”

18th Century Natural History 4 / 40 The Context of l’Encyclopédie The work was a sort of manifesto of the French Enlightenment. It was meant to organize all knowledge and make it available to all people. It presented an optimistic account of the role of and scientific practitioners in the development of history – based on the ideal of progress. It sought to organize all of human knowledge into a single, hierarchical system – such that each discipline would find its natural place in this system.

18th Century Natural History 5 / 40 Natural History in l’Encyclopédie

Here we see the divisions of the “historical sciences” dealing with nature under the branch of “memory.” Under “celestial history” we see, grouped together, “history of ,” “history of plants,” and “.” These are purely descriptive sciences, concerned with detailing the things that exist in the natural world. Detail of the contents, natural history Under these we see differences, or divergences.

18th Century Natural History 6 / 40 The Earth and Life Sciences in l’Encyclopédie

Here we see the divisions of the earth and life sciences under the branch of “reason.” and are fundamental and that is nothing that corresponds to our . Zoology is in fact a different science from what we mean by that term today. finds itself between “aerology” and “hydrology,” as a division of . Detail of the contents, the physical The entire division of sciences knowledge is different from ours.

18th Century Natural History 7 / 40 18th Century Natural History 8 / 40 18th Century Natural History 9 / 40 18th Century Natural History 10 / 40 18th Century Natural History 11 / 40 18th Century Natural History 12 / 40 18th Century Natural History 13 / 40 18th Century Natural History 14 / 40 18th Century Natural History 15 / 40 18th Century Natural History 16 / 40 Ideas about generation before the 18th century

There was a long history of interest in generation before the 17th century. For example, (4th c. BCE) and (1578–1657) had studied the development of chick embryos and decided that they demonstrate true growth and the spontaneous production of form. On the other hand, (1637–1680) had shown that , and imago can exist simultaneously, nested inside each other. He had found frogs legs folded up inside young tadpoles. From these findings, he concluded the embryo always contains the full structure of the adult . Indeed, depending on what different researchers used, they seemed to come to different conclusions about the nature of generation.

18th Century Natural History 17 / 40 Epigenesis and Preformation

Throughout the 18th century, naturalists were engaged in an ongoing debate about whether generation and development were primarily the result of epigenesis or preformation. Epigenesis This was the claim that generation and development are the result of true grown through the production of new forms – or rather forms that are not already present in the originating matter.

Preformation This was the position that the final form of the organism was already present in some way in the original matter, the germ – that is, either the sperm or the egg, or perhaps both.

18th Century Natural History 18 / 40 and the animaculists

Antonie van Leeuwenhoek (1632 - 1723), built his own single lens and studied many different microscopic phenomena. Following the suggestion of a colleague, he began to study sperm under the – his own, and that of some 30 other animals. He concluded that sperm was filled with “” or tiny “,” and it was these worms that reached the uterus and began the process of germination. The animaculists believed that the organism was preformed in the sperm, and some believed that all future generations were already present – panspermism.

18th Century Natural History 19 / 40 Trembley’s polyps

In the 1740s, Abraham Trembley (1710–1784) published a number of works on the hydra, or fresh- polyp. He observed it catching prey with tendrils and moving it to a central cavity – which lead him to believe the hydra is an . He cut hydra in half, into several pieces, turned them inside out, and found that they always generated complete . It was difficult for naturalists to understand what was controlling this growth, and, in particular, what was the locus of this control.

18th Century Natural History 20 / 40 Parthenogenesis and ovum preformationists Charles Bonnet (1720–1793) observed that in aphids the females hatched and gave birth without fertilization. He separated the females and males and was able to raise 30 generations from a pure female line.

Bonnet, Contemplation de la nature (1764): “I understand by the word ‘germ’ every pre-ordination, every preformation of parts capable by itself of determining the existence of a or animal.”

Bonnet proposed that the first female of each contained in her ovaries all future members of her line.

Parthenogenesis A natural form of asexual reproduction in which growth and development of embryos occur from an ovum without fertilization.

18th Century Natural History 21 / 40 Spallanzani’s frogs

Lazaro Spallanzani (1729–1799) – working on the such as frogs for his model system – became the world’s foremost expert on sperm. By making tiny taffeta pants for male frogs, and letting them mate normally, he was able to demonstrate that there must be some sort of mixture of the germ cells of both male and female frogs to produce growth – since fertilization happens outside the female’s body. He then put sperm and eggs near each other in glass jars to rule out action at a distance – seminalis. He then performed artificial insemination, by bringing the sperm into contact with the eggs. In the end, however, he decided that the fermentation was due to contact between the seminal fluid and the egg – claiming that the “worms” in the semen were a parasite.

18th Century Natural History 22 / 40 Wolff’s growth and embriogenesis

Caspar Wolff (1734–1794) studied the growth and development of embryos, intestinal tissues, and plants. Because was still not able to make detailed observational studies of complex tissue, he settled as his model system. He observed that structure in plants appears to be produced spontaneously and he could not find any evidence for a miniature plan, or structure, in the seed that developed into the mature plant. Wolff, “De formatione intestinarum,” 1768: “We may conclude that the organs of the body have not always existed, but have been formed successively – no matter how this formation has been brought about. I do not say that it has been brought about by a fortuitous combination of particles, a kind of fermentation, through mechanical causes, through the the activity of the soul, but only that it has been brought about.”

18th Century Natural History 23 / 40 Wolff on plant growth and development

Plant organs appear progressively from amorphous masses of tissue.

18th Century Natural History 24 / 40 Natural history

In the , the colonial European powers began national projects of collecting and classifying the products of the natural world – plants, animals, and minerals. This was an imperial, economic project as much as a scientific one. By the end of the 18th century, there were some 1600 botanical gardens in Europe – the most famous were the Jardin du Roi, Paris (1635), and the Royal Botanic Gardens at Kew, London (1759). There were also numerous gardens in the colonies. Collecting plant and animal specimens became a leisure activity for the upper classes. Note that the term “history” in natural history refers as much to a systematic description as to a temporal account.

18th Century Natural History 25 / 40 Carl von Linné, Linnaeus (1707–1778)

A Swedish botanist, physician and zoologist. Known for developing binomial . Studied at , and, after studying abroad in Holland for three years, returned to become professor of and botany. His most famous work was , 10th ed., 1758. By the time of his death, he was one of the most famous people in all of By Hendrik Hollander, 1853 Europe.

18th Century Natural History 26 / 40 A system of nature

Linnaeus, Systema naturae (1735): “The first step in wisdom is to know the things themselves. This consists in having a true idea of the objects; objects are distinguished and known by classifying them methodically and giving them appropriate names. Therefore classification and name-giving will be the foundation of our science.” Linnaeus introduced a system – originally in 12 pages and later expanded – of dividing living organism into groups: (animal, plant, ), , , genera and species, each stated with characteristics, differences, synonyms, and locations.

18th Century Natural History 27 / 40 A sexual classification of plants

Linnaeus classified plants based on the number and order of their sex organs. He divided them into classes based on the number of and character of the – the pollen producing part – and into orders based on the number and character of the pistil – the ovule producing part. He introduced terminology such as monandria (one husband), diantria (two husbands), and so on, which were regarded as scandalous at the time, but are still used today.

18th Century Natural History 28 / 40 An early spreadsheet Linnaeus’s order of “pecora” – livestock

Here we see the section of Linnaeus’s chart on livestock. The genera, in the 2nd column, are camel, dear, goat, , and cow. The 3rd column states some differentiating characteristics and the 4th column states the species.

18th Century Natural History 30 / 40

For the animal kingdom, Linnaeus could find no comparable organizing principle and hence set out his system using differentiation based on arbitrary morphological criterial (3rd column). One of his most significant contributions was the system of binomial nomenclature, in which the proper, scientific name of each species is given by two (or Latinized Greek) words: Homo sapiens The gives the type and the species name is descriptive. In this way, organisms equus = horse, sus = pig, cervus all have a proper name – for which reason = deer, capra = goat, ovis = Linnaeus was called the Second Adam. sheep, bos = cow

18th Century Natural History 31 / 40 On the genera and species of plants

Linnaeus, Genera planatarum (1737)

“The SPECIES are as numerous as the different and constant forms of vegetables, which exist upon the globe; which forms according to instinctive laws of generation produce others, similar to themselves, but in greater numbers. Hence, there are as many Species, as there are different forms or structures of Plants now existing; except such less-different Varieties, which situation or accident has occasion’d. The GENERA are as numerous, as the common proximate attributes of the different species, as they were created in the beginning; this is confirmed by revelation, discovery, , hence THE GENERA ARE ALL NATURAL.”

18th Century Natural History 32 / 40 A practical system

Linnaeus eventually acknowledged that his system probably did not reflect the real, natural order, but he maintained that is was useful as a practical system for identifying and organizing living things. Nevertheless, he regarded naming and classifying as connected to the worship of God – whose creations were being named. We can see a Biblical reference here. In his public writings he professed to believe that God created all species and that no new species had arisen since creation, but privately he began to doubt the permanence of species. The final edition of Systema naturae makes no theoretical definition of species.

18th Century Natural History 33 / 40 Georges-Louis Leclerc, Comte de Buffon (1707–1788)

Born to a minor, but wealthy, house of civil servants. Educated at a Jesuit collage, and then studied law. After spending some time in England and receiving his inheritance, he moved to Paris, where he made the aquantance of a number of famous philosophes. In 1739, he was made Keeper of the Jardin du Roi. His magnum opus was the , in some 36 volumes. By François-Hubert Drouais

18th Century Natural History 34 / 40 Buffon’s work

Buffon disagreed with Linnaeus that any artificial classification could be useful. He maintained that there were only individuals in nature and that all attempts to impose order on this was simply an imposition of our own categories. Buffon, “Premier discours…,” 1744: “The more one increases the number and divisions in natural things, the closer one will approach the truth, since there actually exist in nature only individuals … The Genera, Orders, and Classes exist only in our imagination.”

In order to understand the way that individuals were naturally related to one another, we would have to look for causal connections, and these could only be found through discovering their historical, developmental relationships.

18th Century Natural History 35 / 40 The “”

Buffon returned to an old concept as his ordering principle – the “Great Chain of Being.” This proposed a linear, hierarchical system in which all beings were arranged from simplest to most complex. For Buffon it was a chain of gradual degradation with (white European) man on top. Buffon, “Premier discours…,” 1744: “One can descend by almost insensible degrees from the most perfect creature to the most disorganized matter. It will be seen that these imperceptible gradations are the great work of Nature.” Because there were continuous gradations, there could be no hope of real classification. Instead Buffon proposed interfertility as the criterion for species. Hence, he considered all to be the same species, although he proposed that white Europeans were the original, “most beautiful,” stock.

18th Century Natural History 36 / 40 Histoire naturelle

Buffon spent some 50 years working on his masterpiece, but was only able to cover minerals, and quadrupeds. There were also supplementary volumes, including one called Époques de la nature. Buffon preserved the seven days of Biblical creation by arguing that there had been seven epochs in the development of the earth. 1st The earth and other planets were formed as the result of the collision of the and a . 2nd The earth hardened and congealed into a solid body. 3rd The earth was covered by a universal ocean.

18th Century Natural History 37 / 40 An historical development

4th Volcanic activity changed the surface of the earth. 5th The land was exposed – plants and animals began to appear. 6th The original landmass began to separate and the continents were formed. 7th Human beings appeared.

Despite this seeming nod to scripture, his description of all of these processes was purely natural. He argued that the traits of living beings were produced by historical processes, and returned to the ancient idea of the capriciousness of nature.

18th Century Natural History 38 / 40 A secular natural history

Like many of his contemporary philosophes, Buffon proposed to describe the natural world using only natural processes and natural explanations. He was drawn to the secular authors of antiquity – such as Aristotle and Pliny – as opposed to the overtly Christian writers of the . Buffon’s account reified nature and argued that the living world exhibited law-like behavior and that the laws governing the living world could be discovered – just like the laws governing the physical world. Indeed, he challenged the idea of the perfection of nature. In 1751, he was summoned to Faculty of at the Sorbonne and told that some of his ideas were in conflict with religious dogma. Buffon acknowledged the authority of the Church and promised to better hide his speculations.

18th Century Natural History 39 / 40 Overview

We have looked at the role of science in the European Enlightenment, and especially the role of the Encyclopédie ou Dictionnaire Raisonné de Sciences. We went through some debates about growth and development in the 18th century, especially with regard to epigenesis and preformation. We discussed the work and ideas of two of the most famous and influential natural historians of the 18th century – Linnaeus and Buffon.

18th Century Natural History 40 / 40