The Collected Works of Descartes, Volume 1: Correspondence

3 regarding Balzac Jean-Louis Guez de Balzac, a famous French writer and contemporary of Descartes. and addressed to him (Letters 100–102).
8 to various individuals (Letters 103–110), only one of whom is named: "Mr. de Zuytlichem" Constantijn Huygens, Lord of Zuilichem, a Dutch diplomat and father of the scientist Christiaan Huygens. (Letter 106).
2 to Mersenne Marin Mersenne, the Minim friar who acted as the central hub for the European "Republic of Letters." (Letters 111 and 112).
4 to a Reverend Jesuit Father (Letters 113–116).
3 to Clerselier (Letters 117–119).

Clerselier had skillfully chosen the letters for this volume: though professional mathematicians did not find what they were looking for—as Christiaan Huygens wrote on March 2, 1657—on the other hand, the public, which takes more interest in questions of ethics, physics, and even medicine, found much to satisfy them. Furthermore, the names of Queen Christina and Princess Elizabeth—both still living—as well as Balzac, not to mention that English gentleman, Mr. More Henry More, the Cambridge Platonist., and a certain nobleman whose name was not mentioned, were bound to attract attention and bring honor to the philosopher who had been in correspondence with such eminent figures. The book's success was guaranteed; two years later, when Clerselier published his second volume, he noted in the Preface that the first was already "entirely sold out."

In the 17th century, when an author's ideas were valued above all else, one might have been satisfied with this edition. But we have become more demanding; we ask at least two things of a collection of correspondence: first, that it be complete—that is, two-sided, including the letters from the correspondents as well as those of the author; second, that the whole be arranged in chronological order. Now, these two elements are sorely lacking in Clerselier's edition; they even seem to have been the least of his concerns.

In France, however, he did obtain from J.-B. Morin Jean-Baptiste Morin, a professor of mathematics and a critic of Descartes., Professor at the Royal College Now the Collège de France., the communication of several letters written to Descartes as well as the replies. Even so, of the seven pieces in this correspondence, the first (Letter 57), written long before the others, is not dated; but one then finds several...