A series of essays and letters argues for Darwinian natural selection, outlining its evidence, clarifying misconceptions, and urging careful scientific and theological consideration. The author examines objections such as the Noachian flood and contested chronologies, explores the relation of instinct and reason and continuity between human and animal nature, and discusses geological incompleteness and hypotheses like spontaneous generation. Short replies to correspondents show engagement with specific criticisms, while technical notes treat topics from fossil oysters and the first vertebrates to mathematical tests of natural selection. The overall aim is to present complex scientific arguments clearly for educated non-specialists.