c CUNYB/Clarke December, :
The French Liar’s Monkey and the Utrecht Crisis If you are so inclined, I have a very effective way of confounding him. For example,
if you were to write him a very short letter, in which you tell him that you have been
informed that there is a book against me in production, on pageof which are the
words, etc. [Descartes had quoted a sentence from the book, in which he is described
as seeking the protection of the Jesuits, against the criticism of Mersenne and other
French theologians and philosophers.] You were very surprised at this, because when
yousawthat he had said something similar in his theses [on substantial forms,and
December], you had written to correct him, etc. You might also mention in
this letter that he had already written to you two or three years ago, to request that you
write against me. You replied, however, that you would do so very willingly if you had
any reason to do so, and if he were to send you details of what he or his associates found
objectionable in my writings, and that he had not replied to you. You had therefore
concluded that it was purely out of malice that he wished to provoke you against me,
and you were now writing him this letter, and sending it to me, open, for forwarding
to him, to let me know that you were dissociating yourself from what he wrote about
me. If you were to write such a letter, and if I were to have it published, that would
undermine his credibility. (iii.–)
This is typical of the clever manipulation of supportive friends that
Descartes used against his critics. Mersenne wrote the letter as requested
on December, in Latin (so that Voetius could read it without
difficulty).However, rather than forward it to Voetius as originally
agreed, Descartes claimed that he was embarrassed by the generosity of
Mersenne’s compliments, and he decided instead to ask Huygens to act as
an intermediary with Voetius.
Descartes now approached Huygens (January)totell him that
when he had alerted Mersenne to some of the claims made by Voetius,
Mersenne had volunteered to write a letter in his defence. This con-
cealed from Huygens the fact that the suggestion about writing the letter
had come originally from Descartes, who had asked Mersenne to send it
unsealed to Descartes so that he could forward it to Voetius. His clever
ploy now placed him in a quandary. ‘However, since that could involve him
[Mersenne] in controversy if the other person [Voetius] found out that the
letter passed through my hands, I am taking the liberty of putting it in
your hands. I ask you to agree to assume that it was Father Mersenne who
sent it to you directly from Paris and who commended it to your care’
(iii.). This was also designed, as Descartes wrote, to undermine
the credibility of Voetius as publicly as possible. However, despite the
objective of silencing his Dutch critic, Descartes had an even stronger
desire to engage in a public row with Voetius. He therefore suggested that
Huygens burn the compromising letter from Mersenne if he thought it