Saturday, September 6, 2008

The Rise of Modern Geology

In most modern texts the credit for the development of modern geology goes to folks like James Hutton and Charles Lyell. Perhaps the term "uniformitarianism" rings a bell, describing the approach that "the present is the key to the past." In other words, all geologic phenomena, past and present, can be described by the same processes we see today acting over long periods of time. Earth's history is therefore uniform and accessible to scientists today. Proponents of the other historical tradition , the catastrophists of the 17th, 18th, and 19th centuries, are dismissed as religiously motivated quacks. Their theories only retarded science, while Hutton and Lyell paved the way for our modern understanding of the Earth. Historians have shown this common narrative to be yet another myth (see here or here) concerning science and religion.

This time, Charles Lyell in the 19th century and C.G. Gillespies in the 20th may be blamed in part for perpetrating this myth. Lyell, in his Principles of Geology, spent some time in the introduction framing the catastrophists as religious folk whose theories were based on religious bias and miracles rather than scientific evidence. Gillespies in his 1951 book Genesis and Geology set up the narrative describing certain early geologists (Hutton and Lyell) as the true founders of the discipline while ignoring the contributions of others. Catastrophists were portrayed as religious and as only impeding science by, among other things, sticking to a Biblical time scale and invoking supernatural events like Noah's flood.

The truth, of course, is more complicated. In an attempt to keep this short, I will bullet the main points:

  • First, it is true that 17th century Protestants argued for a young Earth and influenced the study of natural history in a way that did not exactly parallel our modern approach. However, the priests and theologians were studying natural history and were certainly a major part of the tradition which led to our modern approach.
  • Some catastrophists were Christians; others were not. Many made significant contributions to geology. Most were not concerned with the exact age of the Earth at all.
  • Those catastrophists who did argue for a natural history more in line with scripture were British; in other words, this was an isolated phenomena, not representative of the tradition as a whole.
  • Neptunism, a movement within catastrophism which invoked water and floods to explain geologic phenomena often had nothing to do with supernatural events like Noah's flood. Most catastrophists, Christian or otherwise, were perfectly content invoking natural events to explain natural history.
  • Catastrophists like Cuvier, Hooker, Humbolt, Sedgwick, Murchison, Werner, and de Maillet all made contributions to modern geology, including the understanding that the Earth's crust is made of ordered layers of rocks (the stratigraphical sequence). The importance of this cannot be overestimated.
  • George Cuvier was an eminent paleontologist and catastrophist who established the fact that extinction events had occurred on Earth through catastrophes, not the slow everyday processes of Hutton and Lyell.
  • Hutton and Lyell, far from being paragons of objectivity, were influenced heavily by their own religious beliefs. They were deists.
  • In their theories, the Earth was eternal and ahistorical. This is a direct result of their religious beliefs and is in flat-out contradiction with our modern understanding of the Earth.
  • The catastrophists got it right; our Earth had a beginning and has had major, different historical periods. The Earth and its history is not as "uniform" as Hutton and Lyell would have liked.
  • Catastrophists believed that the Earth was hotter back when it formed and therefore geologic processes like earthquakes and volcanoes have differed throughout geologic time. They were right. We now know that the Earth was originally molten and has been cooling ever since.
  • In short, our modern understanding is a combination of uniformitarian and catastrophist theory. Our Earth is shaped both by slow, everyday processes like weathering, erosion, movement of tectonic plates, and by catastrophic, historical events like the original formation and cooling of the Earth, extinctions, ice ages, and asteroid impacts.
This myth is illustrative of the ambition of people who would like to rewrite history in favor of a chosen few scientists whose taste in worldview more closely mirrors their own. Even non-religious scientists get lumped in with the religious ones and dismissed if they don't fit the desired narrative.

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