All life must pass, as Shakespeare said, "through nature to eternity". Our understanding of that journey is the starting point for this wide-ranging survey. Peter Whitfield describes the long and complex process of discovery that lies behind that achievement, from the earliest times to the 20th century. He shows how people with enquiring minds and a range of beliefs have tried to "build bridges between nature or eternity", and that the history of science, like that of art, is not a simple progression from lower to higher, but a sequence of responses to the world, conditioned by historical circumstances.