The Abacus and the Cross: The Story of the Pope Who Brought the Light of Science to the Dark Ages

By Nancy Marie Brown, Basic Books, 310 pages.

The Dark Ages, including Gerbert of Aurillac's ninth century, were far from the intellectual backwater later scribes have attributed to them. Experimental science flourished, as churchmen sought the truth in astronomy, mathematics, and physics as much as they did from philosophy and the Bible.

Science was, the author shows, an extension of the search for God. Superstition as early as the tenth century was being chased away, as scholars sought to systematize knowledge and education. The cathedral schools at Chartres and Reims, where men were trained for the priesthood, were the leading places of intellectual discovery.

Brown takes readers on an interesting journey, writing biographical vignettes for the many leaders of Europe, religious and royal, who interacted with Gerbert. French Kings Lothar, Louis V, and Hugh Capet; German Emperors Otto II and III, various popes, and scholars such as Abbo of Fleury and Adalbero of Reims come to life.

Brown shows the genius of Gerbert, who as a young Benedictine traveled to Spain to study the latest science coming out of India and the Arab world. He learned how to use and make the astrolabe for measuring time and studying the night sky. He also created the best abacus of the day, and crafted or spread other mathematical advances important even to our own age.

The main argument of The Abacus and the Cross is that the Dark Ages were not dark, and that people were not as superstitious as we think. Open-minded, they eagerly sought new knowledge. The cultural and intellectual cross-fertilization of the Arabic, Visigothic Christian, and Jewish cultures in Spain of this period played an integral role in the development of modern science.

People did not believe that the earth was flat, or that everything could be explained by demons or the will of God. Surprisingly modern in their basic assumptions, they carried some of the Greek tradition of science and learning, even if the main writings had been temporarily lost.

Gerbert as a teacher and church leader in Reims and throughout Europe, including as a royal tutor, played an essential role in spreading the new or renewed science. He corresponded with emperors, popes, and other intellectuals, thereby keeping abreast of the latest intellectual developments.

This correspondence and his unlimited energy and learning helped get him involved in the highest levels of European politics, as Brown notes: "A knowledge of astrology would explain why Gerbert was so welcomed by the pope and the emperor, when he came to Rome from Spain in 970, as a master of mathesis."

Gerbert proved himself useful to rulers time and time again, as he helped design war machines and aided in correspondence and diplomacy. He hit it off so well with young emperor Otto III, the last great hope of a united Christian empire, that Otto unexpectedly made him Pope Sylvester in 999.

Otto died in 1002 and Sylvester in 1003, thus ending the dreams for what Brown, perhaps exaggerating a little, calls a great time of openness compared to the eleventh-century's more zealous, crusading form of religion. The Abacus and the Cross introduces readers not only to Gerbert, but to the entire age.