Lenses and Waves

1690 - TRAITÉ DE LA LUMIÈRE 237
The question now is, to what extent this interpretation of Traité de la
Lumière stands up with regard to his science in general. Historians’ view of
Huygens as a Cartesian at heart has been fostered by his confrontations with
Newton over colors and gravity. They have created the impression that
Huygens refused to accept Newton’s discoveries because they did not fit his
mechanistic conception of nature. I believe that this view of Huygens’
Cartesianism can, and must, be qualified by drawing upon my interpretation
of the development of Traité de la Lumière.
6.3.1 HUYGENS’CARTESIANISM
Huygens himself has given ample reason for seeing him as a Cartesian. In
1693 wrote a commentary of Baillet’s biography of Descartes which
developed into a reflection upon the virtues of his teachings. He went back
to his earliest encounter with Cartesian philosophy:
“When I read this book of Principles for the first time it seemed to me that everything
in the world went as well as it could, and I believed that, when I found some difficulty
in it, it was my fault for not grasping his thought well enough. I was only 15 or 16 years
old. But having since then discovered in it from time to time things visibly false, and
others very little probable I have well returned from the preoccupation where I had
been, and right now I find almost nothing that I can approve of as true in his entire
physics, nor in his metaphysics, nor in his meteors.
What was very pleasant in the beginning when this philosophy began to appear, is
that one understood what Mr. Descartes said, instead of the other philosophers who
gave us words that made nothing comprehensible, such as those qualities, substantial
forms, intentional species, etc. He rejected more universally than anyone before this
impertinent ragbag. But what above all recommended his philosophy, is that he did not
confine himself to instilling distaste for what is old, but that he dared to substitute for it
causes which one can comprehend of all there is in nature.” 83
Concluding his comment with:
“Notwithstanding this little amount of truth I find in the book of Principles of Mr. des
Cartes, I do not deny that he displayed quite a good deal of wit in fabricating, the way
he did, this whole new system, and in giving it such a twist of truth-likeneness as to
make infinitely many people satisfied with it and pleased with it. One may also say that
by presenting those dogmas with much assurance, and becoming a very celebrated
83 OC10, 403. “Il me sembloit lorsque je lus ce livre des Principes la premiere fois que tout alloit le mieux
du monde, et je croiois, quand j’y trouvois quelque difficultè, que c’etoit ma faute de ne pas bien
comprendre sa pensée. Je n’avois que 15 à 16 ans. Mais y ayant du depuis decouvert de temps en temps
des choses visiblement fausses, et d’autres tres peu vraisemblables je fuis fort revenu de la preoccupation
ou j’avois estè, et à l’heure qu’il est je ne trouve presque rien que je puisse approuver comme vray dans
toute la physique ni metaphysique, ni meteores.
Ce qui a fort plu dans le commencement quand cette philosophie à commencè de paroitre, c’est qu’on
entendoit que disoit M. des Cartes, au lieu que les autres philosophes nous donnoient des paroles que ne
faisoient rien comprendre, comme ces qualitez, formes substantielles, especes intentionnelles, etc. Il a
rejettè plus universellement que personne auparavant cet impertinent fatras. Mais ce qui a surtout
recommandé sa philosophie, c’est qu’il n’est pas demeurè à donner du degout pour l’ancienne, mais qu’il a
osè substituer des causes qu’on peut comprendre du tout ce qu’il y a dans la nature.” Also quoted and
translated in Westman, “Problem” 95-96 and 99.