John K. Reed, Peter Klevberg
The closing decades of the eighteenth century saw the beginnings of modern geohistory. Recent work by historians of science have broken through the persistent mythology of Hutton-Playfair-Lyell, and many lessons have been drawn from a better understanding of the early fusion of secularized science and secularized history. But one lesson that has received little attention is the inhibitive role played by “geotheory,” a genre of scientific writing popular in the last half of the eighteenth century. Geotheories were broad systematic attempts to scientifically explain Earth in its totality. They proved a barrier to the development of geology because of (1) their unrealistic scope, (2) unrealistic expectations, and (3) an unrealistic adherence to the hypothetico-deductive method of Newtonian physics, which in turn was related to serious misunderstandings of the limits of science and the nature of history. Numerous geotheories were published, each attempting to build a comprehensive explanation of Earth. By 1800, geotheory had fallen out of favor, replaced by inductive, limited, self-consciously historical investigations. Yet since geotheory reflects an innate drive in the human psyche for comprehensive understanding, it never really died. Our view of science and its disciplines is much different now, but facets of geotheory still exist—evolution being a secular example and grand “Flood models” a creationist manifestation.