'The publication of Mark Francis's volume marks a significant moment not just for Spencer scholarship but for all historians of late nineteenth-century science. A great achievement - the book that Spencer studies has needed for quite some time.' - British Journal for the History of Science'A magisterial study which is likely to remain a standard reference on its subject for many years to come.' - History and Philosophy of the Life Sciences'Francis has produced an important and intelligent book not only on Spencer, but also on his political, scientific, social, and religious context in mid-Victorian Britain. In relocating the assumptions about Victorian politics, social science, and evolutionary biology, this work deserves a wide audience, within and well beyond historical scholarship.' - The Historical Journal