Permeating the Western Christian tradition of natural theology is a metaphor expressing the belief that God is revealed in a complementary pair of sources: the book of scripture and the book of nature. The idea of nature as a book was used by early modern writers as shorthand for the design argument for God's existence. Thomas Browne (1605–1682), for example, wrote, "There are two books from whence I collect my divinity: besides that written one of God, another of his servant, nature, that universal and public manuscript that lies expansed unto the eyes of all" (Religio Medici I.16).

Origins of the metaphor

The metaphor was born at the confluence of a number of streams: the common human experience of the transcendent, the conviction of the reality of divine-human communication, and the Western fascination for books as repositories of knowledge....