The footnote emerges in this book as a singular resource which reveals much about the evolution of modern scholarship and the progress of knowledge in written form. Grafton treats the development of the footnote - a form of proof normally supplied by historians in support of their assertions - as writers on science treat the development of laboratory equipment, statistical arguments and reports on experiments as a complex history. The book begins in the Berlin of the 19th century and explores the work of historian, Leopold von Ranke, who is often credited with inventing documentary history in its modern form. It then looks back to antiquity and forward to the 20th century, offering a theory of the true origins and gradual development of the footnote.