The studies in this second volume by Martin Rudwick (the first being The New Science of Geology: Studies in the Earth Science in the Age of Reform) focus on the figures of Charles Lyell and Charles Darwin. Lyell rose to be of pivotal importance in the second quarter of the 19th century because he challenged other geologists throughout Europe by probing their methods and conclusions to the limit. While adopting their goal of reconstructing the contingent history of the earth, he claimed that the physical processes observable in action in the present could explain far more about the past than was commonly believed, and that it was unnecessary to postulate occasional catastrophic events of still greater intensity. Far more controversial was Lyell’s further claim that the earth and its life had always been in a stable steady state, rather than developing in a broadly linear or directional fashion. His younger friend Charles Darwin first made his name as a Lyellian geologist; Darwin’s early work in geology, studied here, provided important foundations for his later and more famous research on speciation and other biological problems.