100 Chapter 6
was not able to embed that speculation into a coherent picture, as Descartes had. Des-
cartes ’ s decentering of the Earth went a step beyond Copernicus and Kepler because it
grants our sun no special cosmic status; our solar system is merely one vortex among many
others in an endless, eddying expanse with no center or end. Bold as he was, Kepler was
unable to accept such cosmic vastness, to which we shall shortly return.
Though daring in his Monde , Descartes was cautious in this-worldly affairs. He decided
to suppress his treatise rather “ than to have it appear mutilated ” through politic omissions,
as though it were possible to hide its central Copernican argument. Much later, in 1644,
he considered the time ripe to publish his vortex-cosmos in his Principles of Philosophy ,
which had great influence in the succeeding centuries, especially on continental natural
philosophy.^37
After the 1633 – 1634 crisis, Descartes ’ s correspondence contains very little reference to
music. Yet, as Walker pointed out, even in 1640 Descartes was involved in musical discus-
sions, prompted by Mersenne ’ s commission of a vocal setting of a French poem by Joan
Albert Ban, who did not know that it had also been set by a distinguished contemporary,
Antoine Bo ë sset. Mersenne sent both settings to Descartes, who wrote an extensive
response that preferred Bo ë sset; as Walker notes, “ he had certainly examined Bo ë sset ’ s
air with great attention, and his defense of it shows remarkable insight and subtlety. ”^38Figure 6.5
Descartes ’ s depiction of the mechanism of light refraction, from Le Monde ; the whole space should be considered
as filled with balls representing parts of the world-fluid; the straight lines from points L, I, M illustrate the refrac-
tion of rays from those points via the rebound of representative balls at 1, 2, 3 and 4, 5, 6.