The author of this encyclopaedia, Bartholomaeus, was a Franciscan from Oxford who taught at Paris and Magdeburg in the 13th century. Although he used well-known sources such as Pliny, Isidor, or the 'Physilogus', many parts of his book, particularly the geographical chapters, are based on personal observation. 'The third book is valuable for the history of philosophy since he gives a survey of psychology, together with a great number of anatomic-physiological details' (Baumgartner).