The period of Catholic ascendancy was on the whole one of the most deplorable in the history of the human mind. . . . The spirit that shrinks from enquiry as sinful and deems a state of doubt a state of guilt, is the most enduring disease that can afflict the mind of man. Not till the education of Europe passed from the monasteries to the universities, not till Mohammedan science, and classical free thought, and industrial independence broke the sceptre of the Church, did the intellectual revival of Europe begin.