The first edition of this work was received as an authoritative introduction to medieval thought for historians. The book is now issued in a second edition incorporating, besides revisions of detail, an extensive Supplementary Bibliography of recent primary and secondary scholarship and a new concluding chapter which critically surveys and sets in context the implications of the latest research. The text and apparatuses will thus continue to equip readers with a clear overview of the state of the question in a field whose current vigour testifies to its contemporary importance in European intellectual culture.