 He focuses primarily on the track record of secular ethics, citing the role of the Jacobins and Cult of Reason in the Reign of Terror in Revolutionary France, as well as the religious persecution under Soviet state atheism.He also criticizes evolutionary theory, as well as scientism, for Francis Galton's philosophy of eugenics and its influence on Nazi Germany's racial policies, speaking of a "direct line between Darwin, Galton, and Hitler".Further, Liddle criticizes the ethics of Dawkins and atheist philosopher Peter Singer as "tentative" and "wishy-washy".