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The legacy of Linnaeus

Volume 4 Number 1 - January 2007

Magnus Lidén

Där man får tänka och skriva vad man will, där blomstra studier. Där religionen är fri blomstrar landet. Där teologin regerar fungerar intet.

Where there is freedom of speech, science prospers. Where there is religious freedom, the country prospers. In a theocracy nothing prospers (C. Linnaeus, Diaeta naturalis [1733] 129, A. Uggla 1958).

Some of what Linnaeus wrote in the 18th century during a long, productive life may seem alien, or even bizarre, to the modern mind. Did he really believe that swallows hibernate on the bottom of lakes, or that God created, once and for all, immutable species in a single act? At other times he feels very modern, for example, when he comments on superstition, diet, or discusses in detail the behaviour of an insect. Our Swedish national hero has suffered disparate judgments: the romantic picture of the Flower Prince unveiling the secrets of Flora while surrounded by hordes of admiring pupils seems hard to reconcile with the self-sufficient book keeper, jealously guarding his territory while meticulously pigeonholing each and every dry specimen to its appropriate box according to the Methodus (Linnaeus, 1736).

Both pictures are true. Linnaeus was a direct and spontaneous person, normally not hampered by protocol. He made friends but also enemies; his disciples adored and loved him but some of his colleagues in science did not. But was he really a great scientist? Did he make any theoretical or experimental breakthrough, like Darwin or Kepler, or did he just compile things in a new framework? J. Sachs (1875) even argued that Linnaeus had delayed the progress of botany. He was perhaps not a profound theoretician; much (but not all) of his thoughts on ecology, economics, metaphysics or morals were common ideas at the time, and he could occasionally contradict himself. However, genius can take different forms.

Nomina si nescis, perit et cognitio rerum

Without names, no knowledge

It is indisputable that Linnaeus was of immense importance for the development and popularization of botany. Although botanical terminology has developed since his Fundamenta Botanica (1736) and Philosophia Botanica (1751), it still owes its clarity and precision to Linnaeus. His precise and logical descriptions of taxa are more similar to present-day format than to those immediately preceding him. The Sexual System enabled new and old genera to be classified and recorded in a simple and straightforward manner – he did bring order to a former chaos. The binomial system for naming species is more ingenious than Linnaeus himself understood at the time, and – it is my firm conviction – will survive as long as taxonomy. His encyclopaedic project Species Plantarum (1753) is a fantastic achievement based on an encyclopaedic knowledge (containing many mistakes, of course, like all encyclopaedias). Numerous are his contributions based on observation in the field and in the botanic garden on, for example, ecology, aetiology, phenology and ethnobotany – Omniam mirare, etiam tritissima (wherever you look, there is something worthy of a thesis). And, of course, we must thank him for “the Swedish thermometer”, reversing Celsius’ temperature scale, otherwise we would have had a human body temperature of 63 degrees.

Deus creavit, Linnaeus disposuit

God created, Linnaeus classified

But, enough of praise. What about his classification of plants? It has been disproved, hasn’t it? It was newspaper headlines some years ago! As Linnaeus was aware, the Sexual System was completely arbitrary. There are no observations that could disprove or corroborate it. It cannot possibly be “wrong”. However, the lower ranks, genera and species, were treated by Linnaeus (as by us today) as natural taxa, i.e. as individual entities with an existence independent of our observation. This clash between two principles led to inconsistencies, like the placement of, for example, a species with three stamens (Galium triandrum) in Class Tetrandria. Linnaeus’ sense for naturalness simply made him unable to divorce this species from its 4-staminate relatives in the rest of Galium.

The truth is, as all botanists know when not making propaganda, that the Sexual System was already becoming obsolete in the early 19th century certainly to Linnaeus’ delight, had he still been alive. Commonly, the starting point for the quest towards a natural system is taken to be Genera Plantarum by Antoine Laurent de Jussieu (1789). That is to grossly underestimate the attempt made by Linnaeus. He considered the search for a natural system an important undertaking, and in Systema Naturae (1758) he lists 58 Ordines Naturales in the Plant Kingdom. A majority of these we still recognize today, as families, subfamilies or orders. The treatment by de Jussieu is much more elaborate (it is a complete classification down to the level of genus), but its theoretical foundation is not stronger. It is interesting to note that de Jussieu actually did not believe his own system to be “true”. He considered the pattern of life to form a continuum, which could not possibly be reflected by a hierarchical system of groups within groups.

During the18th century, a continuum-view of the order of nature was widespread – from Buffon to de Jussieu and Lamarck – and did not completely give way to the “Linnaean” paradigm of an inclusive hierarchy until A. P. de Candolle. Apart from that, the search for the natural system has been a story of continuous improvement from the time of Linnaeus until today, without any drastic paradigmatic shifts as to how the general pattern of plant biodiversity is depicted. However, we have not only perfected our picture of the natural system; since Darwin we also believe we understand its background: taxa are explained by common ancestry.

It is less well known that Linnaeus also thought about the reason for the occurrence of natural taxa beyond the simple “God’s plan”. He came up with the modern explanation that each of his Ordines Naturales had a single origin, thus explaining the whole Plant Kingdom with only 58 creations. These 58 originally created plants crossed with each other to form the natural genera, which in turn crossed with each other to form the species. The crossings did not result in intermediates and chaos, because the lineages were held together by the female seed producing inner tissue, the medulla, which he considered the most important in reproduction, the male part, the bark (which produced the stamens), only adding superficial variation. The idea is consistent with his view of an increasing land mass that could be extrapolated backwards to a quite small and comprehensible Eden where all animals and plants were within reasonable reach and present in a reasonable number when God brought them before Adam so he could name them (1. Moses 2:19). These fantastic speculations nevertheless give the same basic explanation for the occurrence of natural taxa as we do today – common ancestry. To be fair, it was not all speculation: Linnaeus had correctly observed that land is rising in the mid-Swedish coastland with which he was familiar, and his finds of marine fossils high above sea level confirmed his thesis (Skånska resa, 1751). He noted that they could not be explained by The Flood.

Characterem non constituere genus

Characters do not make the genus.

Like many icons, Linnaeus has been subject to (sometimes deliberate) misinterpretation. If you want to make our point, it is of course easier if you can denigrate the Master by turning him into a straw-man of your own making. For instance, Linnaeus has been portrayed as an Aristotelian or an Essentialist, partly because of his love for catchy aphorisms, but perhaps more because it fits a simplified picture of science as a steadily progressing voyage from ignorance to understanding. However, traces of Aristotelianism and Essentialism survive alongside other world views in present day scientific papers as well as in the 18th century, even in the same individual.

The truth is that Linnaeus was not overly concerned about ontological questions; his approach is pragmatic. Consequently, there are inconsistencies in his works. Although he used terms like “essential”, there is little to suggest that he embraced an Essentialist philosophy. For him these words were equivalent to “taxonomically useful” (see, for example, a brilliant essay by Winsor 2006). You could with equal justification argue that he was an explicit non-Essentialist; the famous phrase above this paragraph is echoed in the modern idea of “taxa as individuals”.

Gud skapade världen till en blomstertapet och satte människan däruppå att spatsera, leva och sig förnöja

God made the world a flowering tapestry and put man thereupon to stroll, live and be happy

Linnaeus was a brilliant teacher, as was testified unanimously by many of his pupils. Much of his teaching was in the field, and his herbationes took the form of veritable triumphal processions. His known students amount to about 500, many of whom made great careers. No fewer than 74 came from other countries. The same appealing traits quick intelligence, pedagogical skill, charm and persuasive abilities – earned him benefactors from the early years, from Stobaeus in Lund, Celsius and Rudbeck in Uppsala to Gronovius, Boerhaave, Burman and Clifford in Holland. The rapid spread of his system is explained first and foremost by its clarity and utility, but without well-timed promotion, money and authority provided by senior scientists, its success would have been less certain. Linnaeus made these men immortal in the names of plant genera. What more could anyone ask for?

Nu begynte hela marken fägna sig och le, nu kommer Flora och sover hos Febus

Now the earth begins to thrive and smile, now Flora comes and sleeps with Phoebus

So starts his Lapland diary. It shows a side of Linnaeus that is very important for his status as a national Swedish monument - his personal and poetic prose, full of love and amazement and yet with remarkable descriptive economy. There are few 18th-century Swedes who can still be read with pleasure, but Linnaeus can. Consequently, his travelogues and other works in Swedish are time and again printed in new editions and read by new generations. Unfortunately, few have been translated into other languages.

In Latin, his language is personal and efficient, not only in the telegrammatic staccato of works such as Species Plantarum. He tells us that the ideal scientific prose (such as his own) should have a clear style with short and precise words and without tautology, and that such writing is easier and more entertaining to read than one that is needlessly embroidered. This recommendation still holds.

Homo, nosce te ipse

Homo, know thyself

Linnaeus is the authority for Homo sapiens. In Systema Naturae Linnaeus “describes” Homo sapiens with the above profound phrase, taken from the inscription on the Delphi temple to Apollo (Gr: gnothi seauton) – which gives food for thought for the spiritually inclined, not least today with the revival of the original gnostic Christianity. Linnaeus himself was, as is well known, deeply religious and rarely missed a sermon if he could avoid it. He knew the Old Testament and the Apocrypha well, and frequently alluded to them in his writings. References to the Gospels or to Jesus are wanting. He thinks that we have been put on Earth to praise the blessed creation of the Lord, and this is our Paradise. He did not seem to entertain the idea of a life after death. Linnaeus’ God is not only the Creator, he is also the Nemesis, and it follows that sinners are punished in this life; innocue vivito numen adest (lead a righteous life – God is everywhere). Much of his religious and ethical speculations were made available only long after his death, when a collection of notes to his son was published as “Nemesis Divina”. Here we are able to see the dark aspects of Linnaeus, and it refutes the criticism that he was uninterested in the social and political arena.

But did he “know” himself? As W. T. Stearn points out (1971), Linnaeus wrote his autobiography five times, and was obviously the human being he himself had studied most closely, and so is the natural choice of type specimen for the species name Homo sapiens. An additional guideline for the choice of Linnaean types is that the chosen element should conform to the original description accompanying the name.

Botanic gardens and Linnaeus2007

Hortus Upsaliensis (now Linnaeus’ Garden), laid out in 1655 by Olof Rudbeck the Elder, was greatly transformed and enriched by Linnaeus. It was essential for his teaching, and important for his botanical works. His demonstrations in the garden were extremely popular, and could attract half the students at the University (which seriously upset envious professors whose students did not attend their lectures). Not only are there numerous references to “HU” in his herbarium, books and letters, it is also indirectly obvious how often he owes his ideas and conclusions to observations in the garden.

This is no less relevant today. As a systematist, I am grateful to botanic gardens for the opportunity to study my plants throughout their life cycle, thus gaining knowledge unavailable from herbarium specimens or restricted field studies. The potential for new discoveries based on botanic garden material in areas unrelated to pure botany – biotechnology, chemistry, and so on – is underexploited. This needs to be stressed to balance the current somewhat one-sided message that the main justification for botanic gardens is plant conservation. Sadly (as I consider conservation important), I cannot credit Linnaeus with much insight in the latter field, although he did emphasise the significance of botanic gardens for education in a broad sense. However, his naming system has greatly facilitated communication between botanists working in botanic gardens all over the world.

It is 300 years since Carl Linnaeus was born “when the cuckoo was announcing the imminence of summer”. In Sweden, Uppsala University, the Royal Swedish Academy of Sciences and the Swedish Linnean Society, and others, are collaborating to highlight Linnaeus2007. The objective is to stimulate interest in natural science among the young, where there has been a serious decline in the last decade. The Tercentenary has also prompted a general evaluation of Linnaean material. Events, exhibitions, flower shows, tours and festivities are planned all over Sweden, especially in Uppsala and indeed in several other countries. Information can be sought on http://www.uu.se/linne2007/, http://www.linnaeus.uu.se and http://www.botan.uu.se. If you have not made a pilgrimage to these revered sites, this is the time to come. I would like to welcome you to Linnaeus’ Garden, Linnaeus’ Garden at Hammarby and Uppsala Botanic Garden this summer!

References

  • Anonymous. A very long time ago. Genesis.
  • Jussieu, A. L. de, 1789. Genera Plantarum, secundum ordines naturales disposita. Paris.
  • Linnaeus, C. 1733 (1958). Diaeta naturalis. Manuscript compiled by A. H. Uggla, Uppsala.
  • Linnaeus, C. 1736. Fundamenta Botanica.
  • Linnaeus, C. 1751. Carl Linnaei Skånska resa: på höga öfverhetens befallning förrättad år 1749. Stockholm.
  • Linnaeus, C. 1751 (2003). Philosophia Botanica. Translated by S. Freer. Oxford.
  • Linnaeus, C. 1753. Species Plantarum, Stockholm.
  • Linnaeus, C. 1758. Systema Naturae, ed. 10, vol. 1. Stockholm.
  • Sachs, J. 1875. Geschichte der Botanik vom 16 Jahrhundert bis 1860. München.
  • Stearn, W. T. In Blunt, W. 1971. The Compleat Naturalist. A life of Linnaeus. London.
  • Winsor, M. P. 2006. Linnaeus’ biology was not essentialist. Ann. Missouri Bot. Gard. 93: 2-7.
Magnus Lidén
E-mail: Magnus.Liden@botan.uu.se
Postal address: Uppsala University Botanical Garden,
Villavägen 8, SE-752 36 Uppsala, Sweden
Tel: +46-18-4712830
Fax: +46-18-4712831
Internet: http://www.botan.uu.se/