Descartes: A Biography

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

 Descartes: A Biography

had referred to it, in a letter to Mersenne in November,hehad

acknowledged that it was in such poor condition that he even had trouble

in reading it himself.He had also dated the original work, in,as

about ‘twelve or thirteen years ago’. In, therefore, he should have

added another two years to his estimate, and that would date the original

work to approximately, the year in whichThe Worldwas completed

in draft.

It seems as if Descartes finally returned to work on the poorly preserved

copy of hisTreatise on Manin the winter of–, and that the fruits

of his new initiative were the essay entitledA Description of the Human

Body, which was published (posthumously) with the first French edition

of the text in.Rather than simply make a clean copy of his original

work, however, he embarked on a more ambitious project of writing a

comprehensive treatise on animal life. This is reflected in a letter he wrote

about one year later, to an unknown correspondent:

As regards the description of animals, I gave up the idea a long time ago of editing

it, not because of negligence or for want of a good intention, but because I now have

a better plan. I had intended simply editing what I thought I knew most certainly

about animal functions, because I had more or less given up hope of finding the causes

of animal formation. However, in thinking about it, I have discovered so many new

things that I have almost no doubt about being able to complete my whole physics as

originally planned, on condition that I have enough free time and the opportunity to

do some experiments.

The revised plan was to do further experiments to explain how animals

are conceived and how they develop from the very beginning of their

lives.He anticipated that the rest of the winter (–)would be

‘the most peaceful time that I shall possibly enjoy in my life’ (v.–).

Picot had left, and the intellectual rows of the past five years seemed

to be abating. If it had been implemented as outlined, Descartes might

have considered adding the results to a revised, expanded edition of the

Principles.For reasons that remain unknown, perhaps because the plan was

too ambitious and his experimental and observational techniques were

limited, this project remained in draft form and was never published

during his life.

Meantime, his thoughts continued to turn toward his native country

and toward the lack of research time that he was likely to experience

with the arrival of spring. ‘I am obliged to return to France in summer,

and to spend the coming winter there too’ (v.). The reason he gave