Ann Blair, CB20 Lecture 18: I. 17th ct views of history of the • Age of earth estimates from combining Bible with ancient history, e.g. archbishop Ussher: Creation on Sun Oct 23, 4004BC • Fossils as jokes of nature (16th) or effects of Noah’s Flood • Speculative histories of earth based on principles of mechanical philosophy (e.g. William Whiston, New Theory of the Earth, 1696)

II. 18th century • Many new empirical observations: stratigraphy, mineralogy, fossils; eruptions and earthquakes • 2 theoretical camps: Neptunism : rocks formed by precipitation from water, e.g. in Flood. vs. Vulcanism: rocks formed by heat and pressure but also volcanic eruptions—need longer time but still a focus on catastrophe • First : Georges Buffon (Epoques de la nature, 1778): 6 days=6 ages of indefinite length (earth age at 75’000 - 3 million years). Age of earth cut loose from age of humankind (which matches biblical creation)

III. (1726-97): Theory of the Earth (1788) • Sedimentation, elevation by heat & pressure, erosion • “no vestige of a beginning, no prospect of an end” • defended by John Playfair, a natural theologian and minister “It is but reasonable that we should extend to the the same liberty of speculation which the astronomer and the mathematician are already in possession of; and this may be done by supposing that the chronology of Moses related only to the human race." Playfair as quoted in Greene, p. 81.

IV. : Principles of Geology (1830-33) • =the other book that Darwin took with him on the Beagle voyage • (rather than catastrophism) • need deep past of earth; fossil record not complete • professional geology: proceed “as if Scriptures did not exist”

Terms to retain: Uniformitarianism, catastrophism, fossil record, vulcanism, neptunism, Hutton, “no vestige of a beginning, no prospect of an end”, scriptural geology, Lyell, Buffon