Online Medieval Sources Bibliography

An Annotated Bibliography of Printed and Online Primary Sources for the Middle Ages

Source Details

Becker, Gustavus, ed., De Natura Rerum Liber (Amsterdam: Verlag Adolf M. Hakkert)

Text name(s): De Natura Rerum Liber; Book on the Nature of Things

Number of pages of primary source text: 80


Dates: 612 - 613

Archival Reference: 

Original Language(s): 

  • Latin


  • Original language included.

Translation Comments: 

Geopolitical Region(s): 

  • Europe


Record Types: 

  • Philosophic Work
  • Treatise - Scientific/Medical

Subject Headings: 

  • Philosophy / Theology
  • Science / Technology
  • Science - Astronomy
  • Classics / Humanism
  • Church Fathers


  • Index
  • Introduction


Saint Isidore, Archbishop of Seville and Doctor of the Church, was one of the most significant figures of Visigothic Spain, exerting a tremendous influence in his own time (through his vigorous participation in the various synods of the early seventh century) as well as on education throughout the Middle Ages (through his extensive writings). His vast learning and debt to the Latin classics has led him to be considered “the last scholar of the ancient world.” The De Natura Rerum, dedicated to King Sisebut, is a manual systematically treating the physical sciences and answering questions on obscure points about the elements and natural phenomena. Though now generally considered to have been a minor work of Isidore’s, it enjoyed massive popularity in the Middle Ages. As is typical of Isidore’s approach, the work makes a point of the fact that it draws from authorities both classical and Christian. This is the authoritative edition of the De Natura Rerum and includes footnotes bearing quotations from texts on which Isidore draws.

Introduction Summary: 

The introduction (29 pp.; in Latin) discusses the significance of the title of the work, the specific sources from which Isidore takes his lead on various topics, and the manuscripts on which the present edition is based.

Cataloger: WLL