matter, were carried around the earth by solid crystalline
spheres. All such bodies moved in circular orbits with a
perfectly uniform motion (Fig. 1). In contrast, below the
sphere of the moon a more degenerate matter, subject to
change and composed from the four elements (earth, air,
fire, and water), moved in more complex and varied ways.
Superimposed upon this basically rational scheme there
emerged a number of less realistic correspondences of
which ASTROLOGYis the best known. By the 16th century
traditional cosmology was under threat. COPERNICUShad
shown that alternatives to Ptolemy could be plausibly de-
veloped (Fig. 2), while observations by BRAHEof comets
revealed the nonexistence of crystalline spheres. Work by
GALILEOdemonstrated that the heavens were no less cor-
ruptible than the earth. The final rejection of the tradi-
tional cosmology came with René Descartes’ presentation
of a more viable mechanical system in the 1640s.
Further reading: Ernst Cassirer, The Individual and
the Cosmos in Renaissance Philosophy (Oxford, U.K.: Black-
well, 1963; new ed. New York: Dover, 2000); S. K. He-
ninger Jr, The Cosmographical Glass: Renaissance Diagrams
of the Universe (San Marino, Calif.: Huntington Library,
1977).
Cossa, Francesco del (1436–c. 1478) Italian painter
Born in Ferrara, Cossa was possibly a pupil, and later
a rival, of Cosimo TURAin that city. He also absorbed the
influence of MANTEGNA and the Florentine painters,
while his best-known work, the fresco series the Months
(completed 1470) in the Palazzo di Schifanoia in Fer-
rara, clearly draws on parallel works by PIERO DELLA
FRANCESCA. Painted for the Este family, the series com-
bines astrological themes with scenes of the daily life of
the court and includes contributions by several of Cossa’s
pupils. Cossa then spent seven years in Bologna, where he
executed a notable polyptych for the altar of San Petronio
(c. 1474), which included a Crucifixion (National Gallery,
Washington) painted in the style of ANDREA DEL
CASTAGNO.Costa, Lorenzo di Ottavio (c. 1460–1535) Italian
painter
Born in Ferrara, Costa probably trained under TURAand
was also influenced at an early stage by the works of ER-
COLE DE’ ROBERTIand Francesco del COSSA. Paintings from
this period include The Concert (National Gallery, Lon-
don). In 1483 he went to Bologna where he executed work
for the Bentivoglio court, decorating the Bentivoglio
palace and going into partnership with the Bolognese
artist Francesco FRANCIA. After succeeding MANTEGNAas
court painter at Mantua (1506) his style became softer and
more atmospheric in quality. Later works, which had a
profound influence upon GIORGIONE, include two Alle-
gories (Louvre, Paris) painted for Isabella d’Este. In his last
years his reputation in Mantua was somewhat eclipsed by
that of GIULIO ROMANO.Coster, Samuel (1579–1665) Dutch dramatist and
surgeon
Coster is important as the founder of the DUYTSCHE ACAD-
EMIEin his native Amsterdam and for his tragedies, which
are in the tradition of SENECA. His Iphigenia (1617) wasCCoosstteerr,, SSaammuueell 1 12211Fig. 1. Ptolemaic system Fig. 2. Copernican systemEarthMoonMercuryVenusSunMarsJupiterSaturnfixed starsMercury
SunEarthMarsJupiterSaturnfixed starsVenusMoonCosmology