Borrowing a decoration program that had already been used in 1494 by Pinturicchio
in the Borgia Apartment in Rome, Signorelli decided to decorate the area below
his frescoes with grotesque ornamental motifs, busts of philosophers and poets,
as well as monochromes illustrating their work.
It is possible that the busts of philosophers and
poets are intended as symbols of reason and moral values, the only instruments
that man can use to keep in check the powerful animal instincts of his nature
and to attain the higher spheres of the spirit.
But one thing is certain: this apparently minor
section, which was painted to a large extent by Signorelli's assistants, contains
fascinating inventions and reaches extraordinary heights of expression.
The artist gives free rein to his imagination in
these grotesques, and the result is comparable only to the scenes that Filippino
Lippi was painting at about the same time in the Strozzi Chapel in the church
of Santa Maria Novella in Florence. The only one of philosophers and poets that
can be identified with certainty is Dante Alighieri, and some of the loveliest
and most famous of the monochromes are illustrations of episodes from the Divine
Comedy, for the most part from Purgatory.
