It was not uncommon in the Middle Ages for a variety of short texts on related themes to be written as separate booklets, and later bound together, or else to be collected up and written out as a group. Sometimes, as in the present case, separate groups of texts are bound together to form a larger group. This volume contains several features pointing to the fact that it was used in Ely in the Middle Ages. The 'Philosophia' (also known as 'De naturis inferiorum et superiorum' or 'About the creation of the world') of the scientist and mathematician Daniel of Morley was an important work which brought Arabic mathematical theory into western thought. Daniel of Morley, who flourished about 1200, left England to study in Toledo, where Arabic texts and teachers were available. His work is addressed to John of Oxford, bishop of Norwich, who supported his work. In his prologue, he complains of the ignorance of the university masters in Paris.