Descartes: A Biography

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 Descartes: A Biography

together, once and for all, than wait for them one at a time, which would

never finish’ (iii.).

In retrospect, it is obvious that this was a relatively insignificant criti-

cism, by one Jesuit priest, of features of Cartesian optics that many other

contemporary commentators had also questioned. Descartes character-

istically turned a minor skirmish into a ‘war’ and misread the situation

as if the whole Jesuit order collectively had authorized Father Bourdin

to speak on its behalf. There are many similarities in the pattern of this

controversy to the earlier row with French mathematicians and to later

disputes with Dutch theologians. Descartes now contrasted unfavourably

the support that he experienced at Utrecht with the carping reaction of

readers in Paris, just as he would subsequently contrast the ignorant crit-

ics at Utrecht with the those who turned out to be receptive supporters

in France.Once again, as in the other disputes, he used Mersenne as

an intermediary for correspondence in both directions. Thus, he wrote

a lengthy rebuttal of Bourdin’s objections from Leiden (July),

and asked Mersenne to forward the letter to the Jesuit college.He also

found, as on previous occasions, that Mersenne compromised his commu-

nications by failing to forward letters in a timely manner. ByAugust,

Mersenne had still not forwarded the letter ofJuly that he had intended

forFather Hayneuve, and Descartes felt obliged to send him another letter

in Latin for transmission to the Jesuit rector.

This was a ruse that Descartes often used. He wrote two letters together,

onefor a trusted correspondent to whom he revealed what he really

thought about something, and the other accompanying letter to be passed

onto someone else as his pretended or official position. So he sent two

letters to Mersenne, one for himself and one to be forwarded to Father

Hayneueve. The letter to Mersenne reveals the extent of Descartes’ fear

of a conspiracy to undermine him, and his dishonesty in providing incon-

sistent interpretations of the same event on the same day.

Having finally realized, both by Father Bourdin’s action and those of many others,

that a significant number of them [Jesuits] speak about me unfavourably and that,

since they have no way of harming me by the strength of their arguments, they have

undertaken to do so by the number of their voices, I have no desire to address them

individually – which would be an infinite and impossible task for me. My plan is to

coerce them either to reveal, once and for all, all the arguments they have against what

I wrote...or else to refuse to do so, which they cannot do without admitting that they

have nothing worth saying. (iii.)