From Kim Stanley Robinson’s “Imagining Abrupt Climate Change : Terraforming Earth” (Amazon Shorts: 31 July 2005):
This view, by the way, was in keeping with a larger and older paradigm called gradualism, the result of a dramatic and controversial paradigm shift of its own from the nineteenth century, one that is still a contested part of our culture wars, having to do with the birth of geology as a field, and its discovery of the immense age of the Earth. Before that, Earth’s history tended to be explained in a kind of Biblical paradigm, in which the Earth was understood to be several thousand years old, because of genealogies in the Bible, so that landscape features tended to be explained by events like Noah’s flood. This kind of “catastrophism” paradigm was what led Josiah Whitney to maintain that Yosemite Valley must have been formed by a cataclysmic earthquake, for instance; there simply hadn’t been time for water and ice to have carved something as hard as granite. It was John Muir who made the gradualist argument for glacial action over millions of years; and the eventual acceptance of his explanation was part of the general shift to gradualist explanations for Earth’s landforms, which also meant there was another time for evolution to have taken place. Gradualism also led by extension to thinking that the various climate regimes of the past had also come about fairly gradually.