260 Fibonacci, Leonardo
Muslim decorative art, characterized by fine motifs.
A popular revolt overthrew the last Marinid, who was
assassinated in 1465, but Fez prospered until after 1500.
Further reading:R. Le Tourneau and H. Terrasse,
“F ̄as,” Encyclopedia of Islam2.818–823; Michael Brett and
Werner Forman, The Moors: Islam in the West(London:
Orbis, 1980); R. Le Tourneau, Fez in the Age of the Marinids
(Norman, Okla.: University of Oklahoma Press, 1961).
Fibonacci, Leonardo (Leonard of Pisa)(ca. 1170–ca.
1240)mathematician
Fibonacci was an Italian mathematician born at Pisa in
about 1170. Scion of a family of prosperous MERCHANTS,
perhaps the Bonacci, he made business trips to North
Africa in the late 12th century. At Bougie in modern Alge-
ria, he learned about Indian numerals and calculus, after
his return to Pisa in 1202 he wrote an important treatise
on the abacus. A revised manuscript of this work began
to circulate in 1228 and included subsequent materials
gathered during his travels to EGYPT,SYRIA,SICILY, and
PROVENCE. His work was fundamental to introducing the
use of Arabic numerals into the practice of Christian
Europe. In addition to summarizing much of Greek and
Arabic mathematical thought, it included Fibonacci’s own
ideas on algebra. This treatise and another book, written
about 1220 on practical geometry and trigonometry,
earned him fame in the learned circles of Italy. Emperor
FREDERICKII invited him to join his court in Sicily about
1225; he became a major participant in the discussions of
mathematics taking place there. He died in, or sometime
soon after, 1240.
Further reading:Leonardo Fibonacci, Liber quadra-
torum: The Book of Squares,trans. L. E. Sigler (Boston:
Academic Press, 1987); Joseph and Frances Gies, Leonard
and Pisa and the New Mathematics of the Middle Ages(New
York: Crowell, 1969); Kurt Vogel, “Fibonacci, Leonardo,”
Dictionary of Scientific Biography,4.604–613.
Ficino, Marsilio (1433–1499) Italian philosopher,
humanist
Marsilio Ficino was born at Figline near FLORENCEon
October 19, 1433, the son of a prominent physician. He
received a traditional education in humane letters and
medicine at the Universities of Florence and PISAand
studied MEDICINE briefly at BOLOGNA. Although his
teacher of PHILOSOPHYat Florence was the Aristotelian
scholar Niccolò di Tignosi da Foligno, Ficino soon
turned to Platonism. With the support of Cosimo de’
MEDICIand as the head of a Platonic Academy in 1462,
he rapidly mastered Greek and began an ambitious pro-
gram of translation of the works of Homer, Hesiod, Pro-
clus, the Corpus hermeticum,PLOTINUS, and PLATO. Begun
in 1463, completed about 1470, and printed in 1484,
Ficino’s was the earliest complete translation of Plato and
was used for several centuries.
The overriding concern in Ficino’s work in Greek
thought was religious. On December 18, 1473, he was
admitted to holy orders and became an official of the
Cathedral of Florence. In his most important original
writing, the Theologia platonica(1469–74), he stressed
the compatibility of philosophy and religion, the har-
mony between Platonic philosophy and Christian revela-
tion. It is essentially a theological commentary on Plato
emphasizing the existence and immortality of the soul.
In Ficino’s view, ancient philosophy was part of the pro-
cess of divine revelation and prepared for the coming of
Christ. By this explication of Platonic doctrines, he
sought to attract JEWS, rationalists, and Aristotelian
skeptics to the true FAITHof Christianity. A loyal Chris-
tian, Ficino argued that in Platonic doctrine he found
the rational philosophical arguments to buttress Chris-
tian theology. Ficino’s last years were troubled by the loss
of power of his patrons, the Medici family, and the
fanaticism of SAVONAROLA. Ficino died at Careggi near
Florence on October 1, 1499. By paradoxically dissociat-
ing antiquity from PAGANISM, he contributed to the
reestablishment of the possibility of harmony betweenMarsilio Ficino, 19th-century etching(Courtesy Library of
Congress)