Descartes: A Biography

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

AFabulous World (–) 

month.He acknowledges that he had originally planned to spend about

three years at Franeker, had he succeeded in persuading Ferrier to join

him so that they could work together to construct a machine for grinding

lenses. He had even hired a young boy who could cook in a French style

to make life comfortable for his guest. But once that plan was abandoned,

his interest in living in Franeker waned.

Meantime, the focus had changed to a much larger project, of writing

a completely new and comprehensive physics, and by Aprilthe scale

of this undertaking had become clearer. Descartes had begun to study

chemistry and anatomy, and was now in a position to promise Mersenne

that, ‘unless I die, [I plan] to have it ready to send to you at the beginning

of the year’ (i.). With a very significant change of projects, and a

change of residence to Amsterdam, Descartes might have been expected

to settle in one place and complete the major work that he had begun.

However, his penchant for the peripatetic life interrupted plans once again.

Although he was considering a journey to England, he told Mersenne in

Aprilthat he would remain in Amsterdam for at least another month,

presumably in anticipation of a visit from Mersenne. The wily Minim

friar had been travelling since September, using his friary in Paris

foralmost a year as a forwarding address, and he was close enough to pay

Descartes a visit.

Leiden,

If Descartes kept this promise, he stayed in Amsterdam until the middle of

Maybutthen left abruptly for Leiden. OnJune, at the age of thirty-

three, he matriculated as a student of mathematics at Leiden University.

He stayed in rented accommodations with Mr. Cornelis Heymensz van

Dam, his wife and five children – one of whom was apparently lodged

with neighbours to make room for paying guests. The reasons for moving

temporarily to Leiden are as unclear as Descartes’ original decision to live

in Franeker.He may have been attracted there by the fact that Golius

had brought back from the Orient an Arabic translation of theConicsof

Apollonius, or by his friendship with Henri Reneri.

Reneri had converted to Calvinism during his earlier studies at Leuven,

and may have met Descartes later through their common acquain-

tance with Beeckman. Despite their different religious affiliations, Reneri

remained throughout his life one of Descartes’ most devoted friends.