This novel text assembles some of the most intriguing voices in modern conservation biology. Collectively they highlight many of the most challenging questions being asked in conservation science today, each of which will benefit from new experiments, new data, and new analyses. The book’s principal aim is to inspire readers to tackle these uncomfortable issues head-on. A second goal is to be reflective and consider how the field has reacted to challenges to orthodoxy, and to what extent have or can these challenges advance conservation science. Furthermore, several chapters discuss how to guard against confirmation bias. The overall goal is that this book will lead to greater conservation of ecosystems and biodiversity by harnessing the engine of constructive scientific scepticism in service of better results.