"Arcane" / "prevailing usage"

Mon Aug 26 14:54:17 CDT 2002

Since I agree with Paul van Rijckevorsel that we should try to stay within a
given thread and not fly off on personal tangents, I feel that I should comment
on Ron Gatrelle's reply. Besides, I had been hoping to develop a common theme
underlying both the "Arcane" and "Prevailing usage" threads, thus weaving them
together rather than branching off.

Ron Gatrelle wrote:

> Martin Spies presented an argument toward his side of the debate.  In
> debate one it to solidify and reinforce their positonal argument, and tear
> down the oponnents arguments by exposing its flaws.  He did a good job of
> what he was supposed to do.

I don't know anybody who "supposed" me to write my message, and I sure hope not
too many others have read my contribution Ron's way. I see no sense in a debate
if everybody's obejective is merely to "solidify and reinforce" one's own
previous position, and "tear down the opponent's argument". Instead, debates
and science are about finding the truth (a huge word) or at least practicable
solutions. In this process I'm ready to accept another argument as better than
mine ("I know nothing, and I prove it every day"), but for that I do expect the
other argument to be convincing.
Consequently, the aim of my contribution was not to present a one-sided
argument, but to try and find (and "reinforce", if you will) the common ground
that, I hope, is still underlying what all of us do: that nomenclature must
work as a useful and practicable tool, as a service to taxonomy and all
'derived' disciplines requiring reasonably stable names of organisms for
meaningful communication.

> I would argue that one great misnomer regarding the word "stability" is
> that it does not mean unalterable - which I think is how many read it as.

With this and the many, convoluted details that follow, Ron is busting an open
door. I don't see anything in any previous message in this thread, including
mine, that disagrees with Ron's assertion. One can hardly argue in favor of
sticking with (but improving) the Code we have and at the same time for strict
and inflexible enforcement of the principle of priority.

My point was that stability of nomenclature is best achieved if taxonomic data
(e.g., taxon concepts and separations, synonymies, spellings) are transparent
and scientifically reproducible for all. Therefore, there can be cases where
accepting "prevailing usage" over an original datum would serve stability, but
these cases and the term "prevailing usage" itself must be clearly defined, for
example as in ICZN Code Article In its present, ill-defined form in
the Code, "prevailing usage" is about to harm the stability of nomenclature.
This point is nicely illustrated by the diverging interpretations of where and
how to apply prevailing usage, presented by various contributors to this
Similarly, don't misunderstand my lament about unhindered synonymies as trying
to avoid all nov. syns. or nov. combs. However, in order for such actions to be
reproducible or falsifiable for the next author, I do think that, for example,
one shouldn't synonymize two taxa 'by hearsay', i.e. without due examination of
type material or at least the work of a previous author who has studied the
type. Analogously, "prevailing usage" would have to be defined such that
'hearsay' publications do not count as much as works by authors who carefully
studied the original data (including any secondary works for which, e.g., the
type was examined). For such a definition, it is not enough to summarily
exclude "checklists" or "catalogs" from the prevailing usage count. There are
catalogs whose authors have examined type material (I've written one myself),
and on the other hand there are so-called revisions whose authors ignored
critical original data.
Unfortunately, we cannot uncritically accept and copy what any previous author
wrote (including our own earlier publications!), and we cannot simply count
occurrences of a name in order to know its true meaning and the proper
taxonomic solution.

It is precisely for these reasons why - obviously - allowing "prevailing usage"
to more and more replace priority will result in unnecessay loads of additional
work for the practicing taxonomist, and in a significant decrease in
(meaningful, long-term!) stability of nomenclature.

> The ICZN code, its glossary, its articles and its Commission are all
> interconnected and interdependant.  It is a gross error to lift out any one
> "part" and hang all arguments from that now isolated segment.  Thus the
> "usage, prevailing...." of the glossary is tempered and moulded by all the
> other elements it comes in contact with.  Further, the code is clearly set
> up with some elements having more say so than others.

Why, then, should the narrower definition of requirements for the specific
cases falling within Article overrule the general definition of
"prevailing usage" in the glossary, with the latter clearly named as the
authority for terms as Wolfgang Lorenz has shown? According to general logic,
and to that of the Code, general definitions apply everywhere where there is no
specific restriction in specific cases. The inverse conclusion is not allowed
within the applicable logical system and hierarchy of Code parts. The reader is
not and cannot seriously be required to search the entire book for possible
detailed explanations of any term. Obviously, Ron, specific Code restrictions
like bar codes on merchandise in a supermarket apply where they are signalled
to apply and should not be placed on goods in another isle where the labels
happen to be missing. Extrapolating such restrictions to other Articles without
relation in content, or even to the entire Code, is exactly the "lifting out
any one part and hanging all arguments from that now isolated segment" that
your above paragraph so rightfully disqualifies. The glossary applies
everywhere, including to all parts of 23.9. and 33., etc. The inverse is not

This is exactly why Chris Thompson criticized that the conditions for the
application of "prevailing usage" were not designed as precisely and
restrictedly elsewhere as they are in, because this precision now
does NOT apply to other Articles where it would be needed just as much in order
to avoid instability and non-sense.

> I don't think any part of the code is sufficient in and of itself.

If this were true, nobody would be able to work with the Code, as you'd have to
read and memorize (!) the entire Code before deciding on any tiny little bit of

> I agree with Martin and others that the foundation must be original
> descriptions and types.  The Principle of Priority.

No, Ron. Types (and original descriptions, and scientific names, and original
spellings, etc., etc.) are not there to maintain priority, they're there to
maintain reproducibility. And priority is there to maintain reproducibility as
well, that's why it should be replaced by "prevailing usage" only in
exceptional cases. For the same reason, the Code values the original
description more than a specimen labeled "type", because specimens and labels
(as media) are much less certain to not have been altered over time, and are
thus less reliable to re-produce the critical information than the original
publication, UNLESS we place the special emphasis on type material that we do
now (see, e.g., the new requirements for types and statements about them in the
ICZN Code fourth edition).

Before this is misunderstood again: Of course I know that old original
descriptions usually don't contain all the necessary information about the
organism they pertain to. But they usually contain the necessary information
for the taxon, for nomenclature. Anything that may be missing - recognizable
descriptions of the organisms, type designations, name emendations or
corrections, etc., can be supplied by the secondary literature, but should be
taken only from publications who can reasonably demonstrate that they reproduce
the content of the original.

Take the following example: a species of insect (small nematoceran Diptera)
described in the nineteenth century, for which there still is material pinned
and determined by the author in his original, well-preserved collection. Many
authors have used the name for 150 years, but the current "prevailing usage"
derives from a 1929 monograph, even though the author of the latter wrote in
the introduction to this work that "Some of the types will, however, require a
second and more minute examination before they can be accurately placed." This
author clearly stated his methods - examination mostly from the whole, pinned
specimen, at magnifications much lower than what is now considered necessary -
and the potentially significant error they involved. Modern reexaminations of
said types indeed often show that the 1929 author's interpretations do not
agree with what the type material would now be identified as. The original
types still possess that status, the 1929 author did not designate any
replacements, nor even list his material studied individually.
In such a situation - and I have a LOT such cases in the group I work on - I
find it completely unjustified within scientific taxonomy to uphold usage after
the 1929 author whose identifications were admittedly uncertain and whose
material can no longer be exactly reproduced, instead of after the original
author from 18xx whose nomenclature has been kept all along, but merely like an
empty shell. It is for such and similar cases, of which I expect hundreds and
hundreds to exist in zoology, that "prevailing usage" MUST be better defined
and more restrictively applied. However, the current ICZN and its Code appear
to be headed in the opposite direction.

As a number of contributors have stated here before: nomenclature has to stay
close to the science it was intended to serve, and must not develop in to an
empty shell or forum of debate to "tear down the opponent's argument" in. And
just so nobody other than Ron misunderstands my argument: it's "prevailing
usage" - not me - that stands for short-term rigidity rather than stability of
nomenclature, and for inconsistency of procedure.

Cheers anyway, for it's all only "Idols of the Market Place" (market? what

Martin Spies
Schraemelstr. 151
D-81247 Muenchen

Email: spies at zi.biologie.uni-muenchen.de

Tel. (ZSM) +49 89 8107 153
Fax (ZSM) +49 89 8107 300

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