>SS: "I have to disagree with David about this. Uniformitarian
>ideas have not been "positively harmful" to science in general,
>but on the contrary highly beneficial....."
>
>DT: We continue to disagree! There has been a long tradition of
>fuzziness about "uniformitarianism", due largely to the immense
>influence of Charles Lyell. Steven Gould has probably done more
>than most in clarifying the issues: the distinction he makes
>between substantive uniformitarianism and methodological
>uniformitarianism is very important.
The history and meaning of uniformitarianism is a wonderful topic for
debate. Every geologist has his or her own understanding of the term, and
it is used inconsistently in the first chapter of most introductory
geology textbooks. Most of David's and my disagreement centers on this
problem. Steve Gould has made a career of taking concepts already in
circulation, putting his own spin on them, and coining new terms to
differentiate his contribution from previous ones (what follows isn't the
only example of this).
Reijer Hooykaas in 1963 correctly differentiated the two aspects of
uniformitarianism prior to Gould (1965) in his pathbreaking book Natural
Law and Divine Miracle: A Historical-Critical Study of the Principle of
Uniformity in Geology, Biology, and Theology. He properly identifies what
Gould terms "methodological uniformitarianism" as actualism, which is
what it should be called and usually is called. This term used to be used
on continental Europe as a synonym for the Anglo-American
uniformitarianism, but Hooykaas was the one who gave it a more restricted
meaning, the "attempt to explain past changes in the earth's surface by
reference to causes now in operation," or as I would put it, the
"uniformity of natural process and law through space and time." We agree
that this idea is an essential, fundamental part of modern science.
Hooykaas also differentiated what Gould terms "substantive
uniformitarianism," calling it simply "uniformitarianism." He identified
this aspect of uniformitarianism as statements about the uniformity of
material conditions, rates of processes, intensities of energy, and
change through time, i.e. a statement not of method, but of substance. As
both Hooykaas and Gould explain, Charles Lyell failed to distinguish the
two aspects of uniformitarianism in his writings, and his legacy unduly
influenced generations of geologists to adopt an overly-rigid,
substantive uniformitarian approach in their interpretation of Earth
processes as they applied methodologically proper uniformitarianism, i.e.
actualism. Well, here we agree, too. I mentioned a number of
noncontroversial examples of this (giant meteorite impacts, giant
floods), and I acknowledged that some geologists based their reef concept
too rigidly on modern reefs by a use of what we might call "Lyellian
uniformitarianism" or "strict uniformitarianism."
We also presumably agree that while actualism is correct, strict Lyellian
substantive uniformitarianism is wrong. As we very well know, past and
present geological processes (think of volcanism, sea-floor spreading,
heat flow, mountain building, petroleum formation, glaciation, sea-level
movements, evaporite formation, etc.) occur at different rates and
intensities; catastrophes and punctuated events have occurred that
effected great change (in addition to the common slow, gradual processes
that also effect great change). This understanding has resulted in the
recent coining of new terms (the "new uniformitarianism" and
"catastrophic uniformitarianism") to recognize that uniformitarianism now
takes into account rare singular and periodic events. But these new terms
are useless, coined by individuals ignorant of the history and meanings
of uniformitarianism. The point is that there can be, and are, different
degrees of substantive uniformitarianism: a strict (and incorrect)
Lyellian uniformitarianism and a more free (and correct) general
uniformitarianism, and as I will argue below, geologists have almost all
been the latter, not the former.
>
>SS: "And Braithwaite, in particular, was not challenging
>uniformitarianism, but rather the careless or imprecise use of
>scientific terminology leading to misinterpretation and
>misunderstanding.
>
>DT: Insofar as Braithwaite was saying that "the present is NOT the
>key to the past", I think he was challenging uniformitarianism.
>Your perception of the way carbonate geologists have behaved is
>not the same as mine.
This is where we disagree. I don't see the majority of or even many
geologists interpreting uniformitarianism in a strict Lyellian sense and
thus making errors of interpretation. Perhaps a few did, but these were
corrected. In the present case, Braithwaite never said "the present is
NOT the key to the past," but rather, "don't invoke the present so
strictly." The present IS the key to the past in both method (actualism)
and substance (general uniformitarianism)--this is why we have modern
geology today. I remember carbonate sedimentologists and stratigraphers
in the late 60's, 70's, and 80's interpreting ancient carbonate buildups
as completely different from modern reefs. They used to call ancient
buildups "reefs," but there was no attempt to force their geometries and
facies into a modern reef model. Modern reefs were used as a guide, not a
straightjacket.
Long before Braithwaite, geologists understood that the past was
different from today in terms of rates, intensities, energy, etc. They
(usually implicitly rather than explicitly) practiced the true meaning of
uniformitarianism, that "Earth processes are generally--not
identically--uniform through time in regard to rates, intensities, and
conditions, for differences of scale and effect will always be present."
Now this is, as far as I am aware, a true statement concerning
uniformitarianism, and I also believe that this is how geology has been
operating for the past thirty years--and before. Geologists have been
appreciating the differences in scale and effect more in later decades
than before, but this is due to new and better evidence, not a change in
method!
>There have been changes since Braithwaite
>wrote his paper - and people have been much more alert to
>shoehorning the data to fit orthodox depositional models.
This statement depends on what you mean by "orthodox." Since science is
fundamentally nonauthoritarian, any researcher with the evidence can
propose any model, orthodox or unorthodox.
>DT: Non-uniformitarian thinking has proved to be quite fruitful in
>other areas of geology...
>
>SS: "A rigid adherence to a certain type of mythological
>uniformitarianism (as in the geological resistance to a giant
>flood creating the channeled scablands, or a giant meteorite
>impact causing the terminal Cretaceous mass extinction) has
>indeed put up roadblocks to progress, but in general
>uniformitarian thinking finally allowed geology to become a
>modern science."
>
>DT: I point to these examples as illustrative of the uniformitarian
>mind-set which has dominated geology for 150 years. The
>recognition that we can be genuine scientists without holding to
>the tenets of substantive uniformitarianism is what has helped
>to clear away these hindrances to progress.
Again, I would claim that the geologists who are genuine scientists DO
hold to the tenets of substantive uniformitarianism, but in a general,
not strict, sense. If you meant "strict substantive uniformitarianism" in
the above paragraph, then I would agree with you!
>
>SS: "I don't know what you imply by "non-uniformitarian
>thinking," but if you mean catastrophism, then I must disagree."
>
>DT: I mean the freedom to consider non-uniformitarian models and
>mechanisms. I am not wanting to impose one doctrinaire system
>with another! I want genuine freedom in science, which means
>that we consider arguments on their merits and do not reject
>interpretations because they do not fit "orthodoxy" (from
>whatever quarter it comes!).
I don't know of any "non-uniformitarian" models that are also scientific.
But you now understand my concept of "uniformitarian." Genuine freedom in
science doesn't mean we can consider everything that comes into our
minds; for instance, we must reject supernatural causes because they
cannot be tested. Is that too orthodox? Some ideas within modern
catastrophism involve supernatural causes (YEC flood geology, for
example), so that is why I mentioned it. Hooykaas points out that
"actualistic catastrophism" was one of the many geological schools in the
early nineteenth century, so some catastrophic formulations would be
completely scientific if supported by the evidence. A number of today's
actualistic catastrophists have taken advantage of this possibility in
recent years. Good for them--it keeps things interesting.
>
>SS: "This is still the view that geologists have today; giant
>local floods and giant meteorite impacts have now been fully
>incorporated into our planet's uniformitarian framework. . .
>
>DT: This is a fair comment about the contemporary scene. The
>question I ask, however, is: how much of this "big picture" is
>a legacy from Lyell, and how much is good science? Has the
>geological community retained the mindset of substantive
>uniformitarianism whilst feeing itself from the straightjacket
>this dogma brings? My answer is: far more than people realise!
Obviously, I think just the opposite: geologists have thrown off the
straightjacket of Lyellian substantive uniformitarianism.
>
>SS: "Many geologists call any organic carbonate buildup that has
>some topographic expression a "reef." . . . True, some
>geologists evaluated fossil reefs on the basis of what they had
>learned about living reefs. This error was not duplicated by
>research geologists who had more extensive knowledge, and was
>therefore never a problem in the scientific literature. ..."
>
>DT: I think it has been an enormous problem! It's one reason for
>Braithwaite writing his paper!
Confusion about the meaning of the word "reef," yes. Source of a problem
in interpreting ancient carbonate buildups, no (IMHO, of course).
>
>>DT: The proposal of Braithwaite, which is supported by the writer,
>>is that the characteristics of modern reefs must be regarded
>>as definitive for all structures described by the word "reef".
>> ....
>SS: "Although this proposal which you support is good, it cannot
>be rigorously implemented.
>
>DT: I'll respond by citing A. Hallam, . . . the non-committal term buildup
>is to be preferred for these structures . . .
I use the term "buildup" as you, Hallam, Braithwaite, et al. recommend. I
reserve the word "reef" for framework, boundstone organic buildups. But
many other geologists use the word "reef" as a general term, and I can
understand them in context. I am just not willing to ask that everyone
agree with me.
>
>SS: I know what they mean, and it doesn't bother me."
>
>DT: It does bother me. It makes me suspect that the user of "reef"
>is carrying a load of (substantive) uniformitarian
>interpretations which are unconsciously imposed on the data.
>
Wow, David, don't be so worried. Some uniformitarian interpretive baggage
is okay. That's how geology is done.
>
>DT: Here are a few other citations I looked out relevant to this:
>First, from A. Hallam, "Facies interpretation and the
>stratigraphic record". W.H. Freeman and Company, Oxford.
>
>"The two best-known areas of extensive carbonate sedimentation,
>on which facies interpretation depends heavily, are the Great
>Bahama Bank and the Persian Gulf." (page 47)
>
>"Ancient carbonate platforms were enormously more extensive than
>modern ones, especially in the Palaeozoic." (page 50)
>
Very true, and well known among carbonate sedimentologists. So we study
the Recent sediments, develop models, and attempt to use them with
ancient carbonate strata as best we can.
>Comment: we study intensively a few localised carbonate
>depositional environments today, and then think that they are
>adequate to model origins of the vast carbonate deposits of the
>past. How can we be so confident? Surely it is a matter of
>methodology: despite our "official" abandonment of substantive
>uniformitarianism, we still believe in it and don't see the need
>to explore alternatives.
>
I agree, the differences of ancient carbonates are often so great that
recent models are inadequate, so new ones were developed based on data
wholey from the rock record. Scientists have confidence in these
models--as with any scientific model--to the extent that predictions they
generate about unknown data are corroborated by additional observations.
I don't know what would be alternatives to actualism and general
uniformitarianism, and they seem to me to still be working okay.
Best regards,
Stve
Steven Schafersman
schafesd@muohio.edu
http://www.muohio.edu/~schafesd/