At the end of the last century Paul Tannery published an article on geometry in eleventh-century Europe, which he began with the following statement:“This is not a chapter in the history of science; it is a study of ignorance, in a period immediately before the introduction into the West of Arab mathematics.”.

The “Scientific Revolution” of the seventeenth century cannot adequately be assessed without an appreciation of the achievements and limitations of those, whether giants or dwarfs, on whose shoulders Galileo and his contemporaries stood. And since for many historians Galileo's main contribution lies in the mathematization of the natural world and especially of time and motion, particular interest attaches to medieval treatises dealing with these questions, above all to those which were in widespread demand early in the sixteenth century.