Descartes: A Biography

c CUNYB/Clarke     December, :

Metaphysics in a Hornet’s Nest (–) 

than before, possibly because he had been ‘humanized by age or

disputes or because...he had to accord some recognition to his beau-

tiful residence.’

The work involved in publishing theMeditationsseems to have con-

cluded an important phase in Descartes’ life. He had failed to get offi-

cial church approval for his metaphysics, thereby leaving him exposed to

unpredictable criticisms from theologians in the future. If the Sorbonne

would not co-operate, he could change allegiance once more and try to

reconcile with the Jesuits instead. He began to take them into his confi-

dence by writing about a new project that he had already begun, which

emerged in due course as thePrinciples of Philosophy.

The Principles of Philosophy

In the course of explaining his grievances about Father Bourdin to the

rector of Clermont College, in August, Descartes acknowledged that

the Jesuits could avoid controversy with him by distinguishing between

mathematics and philosophy, and by claiming special expertise only in the

latter. He went on to say, surprisingly, that he had written about many

things that are usually classified only as philosophy, ‘among other things,

about all the meteors’ (iii.). It is obvious that the boundaries between

mathematics, physics, metaphysics, and theology were rather fluid at the

time and that Descartes was exploiting that fluidity to promote his own

ideas. During the year,hecontinued to discuss all the issues in

physics that had originally motivated him to writeThe World.Hewrote to

Mersenne about the explanation of gravity; about sensitive plants, which

he was hoping to cultivate in Leiden if the Minim would send him seeds

from Paris; about the tides, although this should be kept secret to protect

the novelty ofThe Worldif it were ever published; about constructing

machines that fly like birds, which seemed to Descartes to be possible

in principle but physically impossible; and about the force that makes the

Earth revolve around its own axis each day and around the Sun each year –

something that could also be explained only inThe World.

He decried the baneful influence of astrology, because it seemed to

have contributed to the death of one young man and caused another to

languish in depression after their horoscopes had been cast in Italy.He

cast doubt on the suggestion that a sister of one of the Minims suffered

convulsions because of some kind of supernatural intervention. The cause