Christiaan Huygens – A family affair - Proeven van Vroeger

number of five would be connected to the family de Medici – thus further boosting the dynastic
prestige of the Tuscan familia. Galileo had dedicated the four “wandering stars” of Jupiter to
Cosimo II 259 and Huygens connected Leopold’s name with the last celestial body to be
discovered – Saturn’s moon Titan. And finally, Christiaan’s straightforward flattering, by
stating that he was glad to have found an occasion “to declare publicly how much the better
arts and the better sciences owe you, and amongst them mathematics in the first place, because
you show yourself as its patron and its defender and against the barbarity that increases day
by day.” Huygens increased Leopold’s status as a patron, and asked him to accept the work of
Christiaan as part of “the better sciences.” Just like his “illustrious” ancestors, the prince was
attributed an “innate virtue” and “eminent disposition” that made him fit for this task. 260
But there were more strong elements of strategic self- and family-fashioning to the
presentation of the Systema Saturnia. Christiaan did not only connect his name to Prince
Leopold, but also to two other great authorities: Galileo Galilei and Christiaan Jr.’s father.
Christiaan Jr. put his name on the same level as his renowned predecessor in celestial
observation, by mentioning the moons of Jupiter and Saturn in one breath, dedicating his
discoveries to the de Medici-family in a likewise manner as Galileo did in his Sidereus Nuncius and
asking, like Galileo had done, de Medici’s patronage. Christiaan Jr.’s inspiration from
Galileo’s work does not seem to have stopped with the dedication – the way in which
nous le devons aussi, par ce que, manquant seul jusqu’ici, il complète maintenant la collection des astres
errants et leur nombre de douze: j’oserais presqu’affirmer qu’à l’avenir on n’en trouvera pas davantage.
Ce qui est certain, c’est que les petites planètes existent désormais en nombre égal à celui des planètes
grandes et primaires, parmi lesquelles il faut compter cette Terre, et que les deux groupes ensemble sont
exprimées par le nombre que nous considérons comme parfait, de sorte qu’on pourrait croire que ce
mode d’existence a été prédestiné par la volonté de l’architecte souverain.” HUYGENS, C. (1888) OC.,
Vol. XV, p212-4
259 On Galileo’s dedication of his discovery of Jupiter’s moons to Cosimo II, see: BIAGIOLI, M. (1993)
Galileo, courtier : the practice of science in the culture of absolutism, Chicago, University of Chicago Press.,
chapter 2. This dedication did not go unremarked – for instance Sorbière wrote in 1660: “Et de cette
sorte on a veu en nos iours les Princes de Medicis mis au rang des estoilles par cét admirable Florentin
[Galileo] dont ils fauoriserent les estudes” – to indicate the usefulness of the sciences their patrons.
SORBIÈRE, S., MAURY, J., MORE, A. & HUYGENS, C. (1660) Relations, lettres, et discours de Mr de
Sorbiere, sur diuerses matieres curieuses, A Paris, Chez Robert de Ninuille rué de la Bouclerie au bout du
Pont S. Michel à l'Escu de France & de Nauarre., introduction.
260 HUYGENS, C. (1888) OC., Vol. XV, p218, or: Systema Saturnia, p29. “de declarer publiquement
combien vous doivent les meilleurs arts et les meilleures sciences, et parmi celles-ci les mathématiques en
premier lieu, parce que vous vous montrez leur patron et leur défenseur contre la barbarie grandissante
de jour en jour.” It did not work right away, however. After dedicating his book and discoveries to
Prince Leopold, Huygens waited a few months on the prince’s reaction in vain. After inquiring what had
gone wrong, he learned that he had forgotten one “procedural” detail – he should have sent Leopold a
notificatory personal letter accompanying the book he had sent him (HUYGENS, C. (1888) OC., Vol.
III, No 755); now the prince did not feel obliged to answer Christiaan’s gesture. After sending the letter,
Leopold expressed his gratitude and accepted Christiaan’s gesture. HUYGENS, C. (1888) OC., Vol. III,
No 623 – Boulliau to Christiaan Jr. (Jun. 6, 1659); No. 704 (1660) p5; No 775 – Christiaan Jr. to
Chapelain (Sept. 2, 1660).
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