end CUNYB/Clarke December, :
Notes to Pages– about it’ (i.). Descartes to Mersenne,May:‘Idonot wish to become
involved with theology’ (i.).
.Henri Regnier, or Henricus Reneri, was reared as a Catholic in the Spanish Nether-
lands, but later converted to Calvinism and went to live in the United Provinces.
He studied at Leiden, where he registered as a student of theology (March
) and later as a medical student (October). Cohen (),.
.Although the letter is written in French, Descartes lapses into Latin in the final
paragraph to state that ‘if something is moved in a vacuum, it is moved perpetually
and in exactly the same way’ (i.).
.Descartes to Mersenne,March(i.). Kepler’s work wasDe nive sexan-
gula & grandine acuminata().
.vi.ff.; and Descartes to Mersenne,March(ii.).
.Descartes to Mersenne,March(i.).
.Descartes to Mersenne,March(i.).
.Descartes to Mersenne,April(i.).
.Descartes (), i.; Theo Verbeek, private communication.
.Baillet links this move with a vacancy caused by the death of Franc ̧ois Burgersdijck.
However, Burgersdijck died only five years later. Baillet (), i.–.
.He wrote to Mersenne (March)inpraise of Descartes: ‘He is my light, my
sun, and as Virgil says in theBucolics,Ican say of him too: He will always be a god
to me, that is, by understanding the word “god” as the most eminent among all
mortals in virtue and understanding’ (ii.).
.Descartes to Mersenne,May(i.)
.Descartes to Mersenne,December(i.); Descartes to Mersenne,
October(i.).
.Descartes to Mersenne,April(i.).
.Descartes to Huygens,November(i.). In a letter to Mersenne,
March,hewrote: ‘I admit that Kepler was my first teacher in optics
and I believe that, up to now, he was the most knowledgeable of all about the
subject’ (ii.).
.John Pell to William Cavendish,March(iv.).
.Baillet (), i..
.Descartes to Ville-Bressieux, summer:‘Ihavereturned to wait for you in
Amsterdam, where I have arrived in good health’ (i.). Beeckman mentions
Descartes’ indisposition in a letter to Mersenne,October: ‘Mr Descartes,
with whom I dined in Amsterdam a few days ago, is recovering from a rather
serious illness’ (CM, iii.).
.The problem is a general version of the following question, in which only four
lines are involved. Given four straight lines, find the locus of points from which a
line can be drawn to each of the four lines so that the product of two of these new
lines bears some constant proportion to the product of the other two lines. Pappus
wished to generalize this problem to finding a locus for indefinitelynlines.
.Descartes to Golius, JanuaryandFebruary(.–,–).
Descartes had evidently been working for some time on a number of problems