Descartes: A Biography

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 Descartes: A Biography

to the Pappus problem, had been completed many years earlier. Despite

these protestations, however, he continued to write what amounted to

hundreds of pages of mathematics in defence of hisGeometry.

Descartes was forty-two years old in, and for the first time he

began to refer to his age, his health, and his limited life expectancy. Forty-

two was hardly old age in the seventeenth century. Some of Descartes’

contemporaries lived much longer, although many others succumbed to

the plague or other illnesses at an even earlier age. When Susanna Huygens

died during the summer of(at the age of thirty-eight), Descartes

addressed some of his first reflections on his mortality to her widower. ‘The

white hairs that I am rapidly acquiring warn me that I should study nothing

other than ways of delaying them. That is what I am doing now....This

task takes up so much time that I am resolved to concentrate on that

alone.’He returned to this theme two months later, when writing to

Huygens again, by suggesting that he might live for a hundred years

and that it would not require extraordinary interventions to realize that

ambition.

Ihavenever taken greater care of my health than I am doing at present. Whereas I

used to think that death could deprive me of thirty or forty years at most, it could

not surprise me now unless it took more than a century from me. I think I see clearly

that if only we protect ourselves against certain mistakes that we are accustomed to

make in the way we live, we could reach without further inventions a much longer and

happier old age than we currently achieve. However, since I need more time and more

experiences to investigate everything that is relevant to this subject, I am now working

onacompendium of medicine....I hope to be able to use it to obtain some delay from

nature. (i.)

He told Mersenne in Septemberthat he was surrounded by fevers on

all sides, that everyone in his neighbourhood was affected, and that ‘I am

the only one in this house who has escaped’ (ii.). The following January

he gave a more complete summary of his condition and expectations,

in reply to concerns about his health expressed by Mersenne and other

correspondents when they had not heard from him for some time.

It is thirty years, thank God, since I had any illness that could be called an illness. And

since age has taken away the heat in the liver that formerly attracted me to the army, I

no longer profess anything but cowardice. Since I have learned a little about medicine,

I feel well, and take as much care of myself as a rich man with gout, it seems to me that

Iamfurther from death now than I was in my youth. (ii.)