Taxonomists and bad history

Blogging on Peer-Reviewed ResearchIn a recent paper on biological nomenclature in Zoologica Scripta, Michel Laurin makes the following comment about the stability of Linnean ranks:

However, taxa of the rank of family, genus or species are not more stable. ...

This sad situation should not surprise us because the ranks, on which the traditional (RN) codes are based, are purely artificial. As Ereshefsky (2002: 309) stated, ‘they are ontologically empty designations’. Ranks were initially thought to be objective because, for Linnaeus, each rank reflected the plan of the Creator and could be recognized on the basis of different kinds of characters. For instance, the classes of angiosperms reflected the number and arrangement of stamens, whereas the orders generally reflected the number of pistils (Schmitz et al. 2007: 82). However, this practice did not persist long after Linnaeus; with acceptance that taxon characteristics are generated by evolution, Linnean categories are now devoid of the significance that their creator gave them, and no other justification replaced it. [My bolding]

A classical taxonomists' bit of bad history, relying on the Essentialism Myth. What is wrong about this?

Well, it's just false, actually. Linnaeus's system was known by him to be artificial, and he proposed it as an aid to teaching, learning and employment in the field. No "thoughts of God" at all; while Linnaeus felt that he was the "second Adam", naming once and for all the kinds of organisms, he didn't extend that divine status to the system for which he has become known. As the leading expert on Linnaeus, Staffan Müller-Wille said to me when last we met, Linnaeus was playing with ways to organise large amounts of data, even going to the point of inventing the index card. But he wasn't presenting the natural order. And he knew it. He hoped he could, but never managed to, as I argue here. Instead he's inventing the concept of a database for biology, and the system he invented was a diagnostic system only. It's ontologically empty because it was never intended to be full, just as the Library of Congress classification system doesn't offer an ontology of the written work, just an easy way to retrieve names and texts.

Who did think that ranks were the thoughts of God? Well, it was Louis Agassiz a century after Linnaeus, who explicitly held this, and he was pretty well the only one who did. Agassiz wrote:

... there is a system in nature to which the different systems of authors are successive approximations, more and more closely agreeing with it, in proportion as the human mind has understood nature better. This growing coincidence between our systems and that of nature shows further the identity of the operations of the human and the Divine intellect... [Essay on Classification, 1857: 22f]

He also said, in the same work (p7):

... genera, families, orders, classes, and types have the same foundation in nature as species, and that the individuals living at the time have alone a material existence, they being the bearers, not only of all these different categories of structure upon which the natural system of animals is founded, but also of all the relations which animals sustain to the surrounding world, — thus showing that species do not exist in a different way from the higher groups, as is so generally believed...

This is in opposition to the claim that only the rank species is natural. Agassiz thinks none of these ranks are natural, but that they are real and not artificial:

To me it appears indisputable, that this order and arrangement of our studies are based upon the natural, primitive relations of animal life, — those systems, to which we have given the names of the great leaders of our science who first proposed them, being in truth but translations, into human language, of the thoughts of the Creator. [p8]

In other words, this is God's thoughts and plan. These ranks are real, but not physical.

Now this is interesting largely because, contrary to the essentialist myth, Agassiz was out of the mainstream in this regard. His platonism is almost entirely uninfluential in natural history thereafter. While I have no doubt that if you looked hard enough, you'd find a couple or so naturalists who agreed with Agassiz on this (but as yet I haven't), the vast majority agree, from that time to this, that species are real, higher (Linnean) taxa are not, and species are both physical objects and groups of physical objects. In fact, Mivart, in his Genesis of Species, which was a rejection of many of Darwin's ideas, found it necessary to say that

...the analogy between a “species” and an “individual” is a very incomplete one. The word “individual” denotes a concrete whole with a real, separate, and distinct existence. The word “species,” on the other hand, denotes a peculiar congeries of characters, innate powers and qualities, and a certain nature realized indeed in individuals, but having no separate existence, except ideally as a thought in some mind. Thus the birth of a “species” can only be compared metaphorically, and very imperfectly, with that of an“individual.” [p13f]

Here, Mivart means by "individual" what we would mean by "organism", and his objection is to something like E. O. Wilson's notion of a "superorganism"; but note in this context that Mivart means that species are just groups of organisms, and not anything like Agassiz's thoughts of God, although they can also refer to concepts. And this is the Catholic theistic evolutionist position of the day.

Overall there's no reason to think that the Linnean system was ever intended to be, or understood as, a system of natural ontology, apart from Agassiz. The Naturphilosophen didn't attend much to taxonomy - they were more concerned about the form of parts of idealised organisms like "limbs" and "leaves".

Polly Winsor has written of the origin of the essentialistic myth, as I said above, in which she points out that it arose due to a distaste for Plato in the first instance, and only later Aristotle, who, in any case, held nothing like the views ascribed to him by the myth. But it's a straw target, without substance or much in the way of agency...

Hat tip to Polly for drawing my attention to that sentence.

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Hum, well... I guess there is a hard message to send through... The fact that classifications are artificial doesn't prevent always them to be useful. That's why operative identification handbooks are still so precious. We just have to make it clear that willingness to identify does not necessarily have to reflect a natural history (which is, by the way, also subject to much changes).

Then I wonder if the essentialist approach is not more of an essential step when growing into a natural scientist, when one comes to really realise species and taxon are "something" important. Off course, this usually happens in an early age and this view matures accordingly.

Would it thus be that we naturally ascribe this state as something inherited from historical thinking instead of our own initial (psychologically-driven) baggage? (hey, do anything like psycho-epistemes exist yet? :)

Thanks for starting my day off on an intellectual good foot. It does seem like the sentence in question "Ranks were initially thought to be objective because, for Linnaeus, each rank reflected the plan of the Creator and could be recognized on the basis of different kinds of characters." could benefit with a reference. Since I'm not a taxonomist I probably will never write about Linnaeus, but if I do, for whatever reason, thanks for the lesson.

It is interesting that scientists are often sloppy when it comes to the narrative history of scientific concepts. It's probably because their eye is on the ball of the clarity and utility of the concepts now, and the history is only as a heuristic.

I happen to agree the linnean taxonomy serves more to obscure rather clarify, relative to PN, but trying to make out that it came from a bad place isn't the best way of making that point.

It is interesting that scientists are often sloppy when it comes to the narrative history of scientific concepts.

It is a crying shame that historians are very often even sloppier when it comes to the narrative history of scientific concepts.

John, for years I've enjoyed your posts (both here and on TO) on the bad history perpetuated by scientists. Just wanted to mention that.

For an historian to complain about one sentence in a scientific article, in which an historical statement was slipped in "as a heuristic," that is, a rhetorical flourish only meant to make a point memorable, may seem like a cheap shot. In fact, the complaint is pretty pointless, if all it leads to is that the decorative reference to the past is dropped.
What if we don't drop it, what if we ask history to shed some light? If we can paint a more accurate view of Linnaeus's invention of the ranks, can that actually bring anything useful to the current debate?
The problem is that on the one hand, a fairly accurate view is so long and complicated that the disputants will lose interest before clarity emerges, but on the other hand, a sound-bite must be wrong because it is oversimplified. Oh, well, maybe it's worth a try.
Yes, Linnaeus invented ranks, in the sense that though others before him often had divisions above the level of genus and species, he regularly arranged his genera into orders and classes, furthermore always giving proper names to each taxon. If he was not trying to reveal categories of divine thought (as he surely was not) what was he trying to do? He was putting flags and labels on the layers in his system of classification purely for the purpose of assisting the user. His systems were offered for identification so that a naturalist could find citations to the literature on an organism if it had already been described, or decide if it was new to science and needed to be described. No one imagined him to be saying that an order of insects was somehow comparable to an order of fish or flowers. Many naturalists did not like his style; it was dry, it was authoritarian; his emphasis on sex was crude. In spite of this, his model was soon widely adopted, because it so clearly did achieve exactly what it claimed to do: it assisted communication.
Agassiz's attempt to attach a deeper meaning to the ranks, a hundred years later, was greeted with embarrassed silence by most of his supporters. One of the reasons that so many naturalists accepted evolution so quickly after 1859, even though most were unconvinced by natural selection, was that Darwin's irregular branching made sense of what most of them were already feeling about the clumpy shape of nature. We could almost say Agassiz was the exception who proved the rule.
I've left out genus and species, since Linnaeus did believe that genera were natural, and created by God, but here too his thinking was nothing like Agassiz's. The species rank is a can of worms of a different color that doesn't need kicking in this context.

By Polly Winsor (not verified) on 21 Feb 2008 #permalink

John Conway said it is "interesting" that scientists often make mistakes about history, and Thony C. said it was a "crying shame" that historians did the same or worse. I've spent too many wasted moments myself wringing my hands about this, and would be glad to hear other views.
On the particular instance which started this thread (Michel Laurin's statement that Linnaeus created his ranks in the belief that he was representing God's plan), it is a safe guess that the immediate source of what he takes to be a well known fact was Marc Ereshefsky's 1994 article "Some problems with the Linnaean hierarchy" Philosophy of Science 61: 186-205, which says on p. 188 "the Linnaean hierarchy was devised to represent God's essentialist plan." Marc's sources were Cain and Mayr. My serious challenge to Cain did not come until 2001 and to Mayr a few years later. So, if there is a problem here, it certainly involves communication between people in widely separated disciplines. I hope the blog phenomenon will prove to be a way to lessen such problems in future. Are there any hopeful signs yet of that happening?

By Polly Winsor (not verified) on 22 Feb 2008 #permalink

I'm one of Michel's PhD students, and I think I should mention that Michel recently translated a book on Linnaeus from English into French. Said book (or at least the Swedish original, which was later translated into English) is incredibly detailed, even citing unpublished manuscripts by Linnaeus.

Michel has also sent me his interesting e-mail conversation with Prof. Winsor, but I haven't asked for permission to cite it.

In any case, nobody seems to doubt that Linnaeus believed genera and species were real, and nobody seems to agree with this belief anymore (the joke goes "species speciate, but genera don't generate").

By David Marjanović (not verified) on 22 Feb 2008 #permalink

Reference of the French translation:

SCHMITZ H., UDDENBERG N. & ÖSTENSSON P. 2007. - Linné - le rêve de l'ordre dans la nature. Translated by M. Laurin. Belin, Paris, 255 pp.

And by "recently" I of course meant "before he wrote the paper".

-------------------

Then I wonder if the essentialist approach is not more of an essential step when growing into a natural scientist, when one comes to really realise species and taxon are "something" important.

Wait, wait, wait... taxa are something important. Whether we ascribe the rank of family or order to them is not only not important, but distracting to the point of obfuscation.

There are many studies of biodiversity through time out there that count genera, orders or families as if they were countable.

By David Marjanović (not verified) on 22 Feb 2008 #permalink

Hi folks,

I am currently too busy with other urgent tasks to provide the detailed, documented answer that I would like, but here are a few thought:

My information came not only from Ereshefsky, but also from the 255-page book on Linnaeus which I translated. That book was written mostly by Nils Uddenberg, Professor at the University of Lund and at the University of Uppsala. Since this book is for a broad public, the sources are not cited, but I gather from the text that Nils consulted many other books, articles, and probably even unpublished material pertaining to Linnaeus. The book also confirms what I had read about Linnaeus elsewhere, among other things in the following book :

BLUNT W. 2001. - The compleat naturalist: A life of Linnaeus. Frances Lincoln, 261 p.

My general impression is that Linnaeus was deeply religious, and that he believed that his classification was "natural" and reflected God's creation, although that may have changed between his early works, in which he may have been convinced of this, and his last works, in which he may have doubted it. This certainly happened about his belief in creation: strong at the beginning, and apparenly fading at the end. Similarly, he may have believed more in some ranks than in others, because he apparently considered genera more natural than classes or even species. I will investigate all this when I have time (that may not be for several weeks, or even months because it is a big job in itself), but in the meantime, I am surprised to read on this blog that my work is:

"A classical taxonomists' bit of bad history, relying on the Essentialism Myth. What is wrong about this?

Well, it's just false, actually. Linnaeus's system was known by him to be artificial, and he proposed it as an aid to teaching, learning and employment in the field."

That seems like a bold statement, and I suggest that there are equally valid alternative interpretations of Linnaeus' works. Those of you who might be tempted to write more comments on this might want to start by reading the book which I translated (either in the Swedish original, the English version which I read, or the French version which I wrote), along with my "Splendid isolation" paper (which started this whole discussion).

Finally, and I will end here because of lack of time, I would like to point out that I have long known that RN is not essentialist (although I still think that Linnaeus' work was essentialist, but I will read Dr. Winsor's papers and might change my mind). But all this is really besides the main point of my paper. I stressed the fact that the vast majority of systematists consider ranks artificial, and that this was true even in much of the 19th century, and I suspect that many of Linnaeus' contemporaries also viewed ranks as purely subjective. Linnaeus may (along whith Agassiz) have been an obvious exception (and perhaps not; I will investigate), but since there is such a long-established consensus, why don't we finally get rid of ranks? I can tell you why it wasn't suggested earlier: ranks are required by the rank-based codes, and codes are essential. We can't simply drop codes of biological nomenclature because taxonomy would become even messier than it is now. A viable alternative is essential, and until very recently, there was none (no alternative proposal was sufficiently elaborated and supported by enough scientists to provide a viable alternative). That alternative now exists: the ICPN (International Code of Phylogenetic Nomenclature), also known as the PhyloCode, which was initially posted on the web (as a preliminary draft) in 2000. Now, dropping ranks becomes possible, and the natural taxonomy that Linnaeus, Darwin and many others dreamt about finally becomes possible. Let's do it!

Michel Laurin

Dr Laurin

Please don't misread what I wrote here: I am not saying that anybody thought that higher ranks were not artificial apart from Agassiz. And I am not engaging the point of your paper, although I have some concerns about the Phylocode which are neither here nor there. My only point was that the notion that ranks were something in the mind of God or real is a conflation of various historical sources that were "mashed" in the period from 1958 or so to 1982 when Mayr published his Growth and Linnaeus has been demonised as "pre-Darwinian" (as if he could be anything else) and "essentialist". He wasn't essentialist in any theoretical or ontological way, in the reading I have done.

Unfortunately the book you translated is not available to me, but Blunt is, and I don't recall any evidence for your one-sentence claim in that book. However, it's been a few years since I read it - perhaps you could send me some documentary citations, and I will put them up if you like.

In the Phylocode Wars, the term "ranks" is a hot button topic. And yes, Linnaeus gave ranks (only five, compared to the 40-plus of today), but if they are not real, either in Linnaeus' view or the view of anyone since, then it doesn't matter that we use them; they are mere conveniences. And as conventions, they have a certain usefulness that many are loathe to abandon. That's a disciplinary matter, not for philosophers to say.

I think that Marc is merely repeating Mayr's and Cain's dogma, as Polly noted above. The "Linnean hierarchy" is a constructed strawman in many ways, and partly due to the overblown claims of its modern defenders. The uses of history by scientists, including, and in particular, taxonomists, has been an interesting theme of Polly's work. As "metahistory" it is of interest to historians and philosophers that scientists even need to use history for polemic purposes, but as some say, those who write the history determine the present. It is at least worthwhile to point out the mistakes made in the process.

Yours is not the most egregious example of this. Of course that honour goes to Mayr and his students and colleagues who try to make out that Growth really is how the history went. But even if it doesn't affect the thesis of your paper, it's worth pointing out when it is repeated.

Many thanks for dropping by. It's not often we get the victims/subjects of the blog come visit.

One hopes that museum specimens will still be arranged on the shelves as they have been in the past. For fishes, the grouping is by families as defined by Jordan or Berg, or whoever. Then the jars are arranged alphabetically by genera and then alphabetically by species within genera. If a specialist has looked through the family collection, the genra and species may have been reidentified and moved around appropriately. The families stay fairly stable and do not generally reflect later thinking about family relationships. I've worked in a collection where the curators tried to track changes in phylogeny. I did not expect this, and found it a bit confusing until I caught on to what they had been up to.

By Jim Thomerson (not verified) on 24 Feb 2008 #permalink