Following Michael Bartholomew's study of ‘Lyell and Evolution’ in 1973, scholars have become increasingly interested in the response of gentlemen geologists to Lamarckism during the reign of William IV (1830–7). Bartholomew contended that Charles Lyell was ‘alone in scenting the danger’ for man of using transmutation to explain fossil progression, and that he reacted to the threat of bestialisation by restructuring palaeontology along safe non-progressionist lines. Like his Anglican contemporaries, Lyell was concerned to prove that man was no transformed ape, (...) and that morals were not the better part of brute instinct. Dov Ospovat has subsequently suggested that Lyell's theory of climate was equally an attempt to thwart the transformists and ‘preserve man's unique status in creation’. In other words, Lyell's biology and geology were inextricably related inPrinciples of Geologyand his ideology affected his science as a whole. Finally, Pietro Corsi has identified the Continental materialists who most probably alerted Lyell to the danger, intimating that a conservative British response became imperative when Lyell ‘saw signs of the diffusion of transformism in England itself, where it could even form an unholy alliance with prevailing progressionist and directionalist interpretations of the history of life on earth’. (shrink)

The theoretical system Lyell presented in 1830 was composed of three requirements or principles: 1) the Uniformity Principle which states that past geological events must be explained by the same causes now in operation; 2) the Uniformity of Rate Principle which states that geological laws operate with the same force as at present; 3) the Steady-state Principle which states that the earth does not undergo any directional change. The three principles form a single thesis called uniformitarianism which has been repeatedly (...) questioned and which has been reputed to be unable to face the competing directional synthesis based on the theory of the earth's cooling down. As a result, the significance of Lyell's system has been reduced to a simple actualism which admits the validity of the only Uniformity Principle. I believe that the only way to understand Lyell's role in the history of science is to maintain the unity of his synthesis. To show the Newtonian roots of this synthesis I will compare Lyell's principles and Newton's Rules of Reasoning. I will conclude with an analysis of the methodological function of principles in Lyell's scientific endeavour. (shrink)