Isidore Knew All There Was to Know

Dan Graves, MSL

Isidore Knew All There Was to Know

Isidore, Bishop of Seville, lived in an age when little ancient science was remembered in Europe. He collected whatever lore he could find into his twenty volume Originum seu Etymologiarum libri XX (also called De rerum natura, On the Nature of Things). Needless to say, it was just as inaccurate as its sources. Its real advance was in its organizational improvement over Pliny's similar encyclopedia. So popular did it become that portions of over one thousand copies are still in existence fourteen hundred years later.

The Originum was the labor of many years. Isidore amassed it in spite of the heavy spiritual and administrative duties placed upon him after he became archbishop in 599, the year his older brother, Leander, who had held the post, died. The first Christian work of its kind in Spain, parts circulated before his death.

Interestingly, Isidore showed none of the narrowness characteristic of Spain in a later age. The Originum does not start from theology as did many other Medieval encyclopedias. On the contrary, Isidore considered liberal arts and secular learning the foundation for Christian education. In one of his writings, Regula Monachorum, he envisioned the ideal monastic community as including a library complete with secular works, although he says it would be better to be without the knowledge in such books than to be misled by their heretical contents. He borrowed freely from the pagans, especially from Latin sources. His Christian sources included the innovators Boethius and Augustine of Hippo. Isidore defended Christianity against the Jews and defended Christ's divinity against Arianism.

Isidore wrote little that was original, content to glean the labors of the past--enough of a job for any man in his position. Nonetheless his work is considered useful, especially to those seeking the technical meanings of Latin terms. Its science holds nothing new, sharing with alchemists a belief in the existence of four fundamental qualities: coldness, dryness, wetness and hotness. Dealing with scriptural numbers in Liber numerorum, he became mystical and fanciful. One section of his work was devoted to medicine and gave monks some healing knowledge.

At root of Isidore's concern for science was his desire to reform the church through discipline and the establishment of schools. His textbooks exerted considerable influence in the centuries to come. Rhabanus Maurus, for example, drew heavily on Isidore's work in preparing his own. In England, The Venerable Bede consulted him and Aldhelm cited him.

Isidore was educated by Leander and in the schools of the monks. The thinking of the day was largely analogical rather than analytical. Isidore accepted this view with all its limitations. Nonetheless his work demonstrates the very high sense of responsibility many Medieval theologians exhibited toward the preservation of learning. Without Isidore's efforts, the Medieval world would have been much poorer of knowledge. The Originum, incomplete at his death on this date, April 4, 636, was edited and issued by his friend and disciple Bishop Braulio.


  1. Bell, Mrs. Arthur. Saints in Christian Art. London: George Bell, 1901 - 1904.
  2. Collison, Robert Lewis. Encyclopaedias: their history throughout the ages; a bibliographical guide with extensive historical notes to the general encyclopaedias issued throughout the world from 350 B.C. to the present day. New York, Hafner Pub. Co., 1964.
  3. Copleston, Frederick. History of Philisophy. Various editions.
  4. Hunter Blair, Peter. The World of Bede. Cambridge, England: Cambridge University Press, 1990; chapter 13, "Spanish Influences."
  5. "Isidore of Seville." Dictionary of Scientific Biography. Editor Charles Coulston Gillispie. New York: Scribner, 1970 - 1980.
  6. "Isidore, St." The Oxford Dictionary of the Christian Church. Edited by F. L. Cross and E. A. Livingstone. Oxford, 1997.
  7. Johnson, Paul. History of Christianity. New York: Atheneum, 1976.
  8. O'Connor, John B. "St. Isidore of Seville." The Catholic Encyclopedia. New York: Robert Appleton, 1914.
  9. Singer, Charles Joseph. A Short History of Medicine, by Charles Singer and E. Ashworth Underwood. Oxford, Clarendon Press, 1962.
  10. Various encyclopedia and internet articles.

Last updated April, 2007.

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