Science unbound: In this book, the author explores Comprehensive Scientism by juxtaposing the philosophies of one challenging figure of the European Enlightenment with those of a legendary evolutionary biologist. Paul Henri Thiry d'Holbach lived from 1723-1789 and wrote one monumental work known as 'the Bible of atheists'. Richard Dawkins, a modern-day scientist and self-declared atheist, is currently galvanizing the secularist movement'. Gerold Reisinger's treatise aims to uncover the motives of d'Holbach and Dawkins for claiming that science is the only source of knowledge to defend atheism. Various aspects of their forms of scientism are outlined and elucidated in relation to the comprehensive form that combines epistemological, ontological, moral and existential scientism. Basic research by Stenmark and Peels frames this philosophical work's analysis and comparison of the two iconic philosophers and their writings. The book shows that scientism is what unites their positions and proves to be as powerful a motive today as it was in the 18th century to render science the know-all and be-all of truth and reality and thereby attempt to obviate religion for humankind.