Stephen Jay Gould's writing remains the modern standard by which popular science writing is judged. Throughout his work Gould has developed a distinctive and personal form of essay to treat great scientific issues in the context of biography. Here, Gould once again applied biographical perspectives to the illumination of key scientific concepts and their history, ranging from the discovery of the new scourge of syphilis by Fracastero in the sixteenth century and Isabelle Duncan's nineteenth-century attempt at reconciling scripture and palaeontology to Freud's weird speculations about human phylogeny and recent creationist attacks on the study of evolution. As always, the essays brilliantly illuminate and elucidate the puzzles and paradoxes great and small that have fuelled the enterprise of science and opened our eyes to a world of unexpected wonders.