title RIASSUNTO /title Fra i manoscritti della British Library stato trovato un codice contenente una copia non autografa dei libri VIII-XI del De vita et doctrina Epicuri, la prima versione manoscritta a noi pervenuta del SYNTAGMA PHILOSOPHICUM di Pierre Gassendi. Se i libri IX-XI, composti fra il 1636 ed il 1637 e dedicati alla canonica epicurea, erano gi conosciuti attraverso il Ms. Carpentras 1832, il libro VIII, terminato nel marzo del 1634, invece quel De philosophiaEpicuri universe, che Pintard, Rochot e Bloch segnalavano come perduto. Questo articolo analizza il contenuto del De philosophia Epicuri universe e mostra come le parti di esso che non furono riversate da Gassendi nel Liber promialis del SYNTAGMA PHILOSOPHICUM (De philosophia universe) vennero integrate nell'apologia De vita et moribus Epicuri pubblicata nel 1647. Contrariamente a quanto si pensava, quest'opera, scritta fra il 1633 ed il 1634, fu infatti modificata da Gassendi prima di essere data alle stampe.
This article analyzes the evolution of Mersenne's views concerning the validity of Galileo's theory of acceleration. After publishing, in 1634, a treatise designed to present empirical evidence in favor of Galileo's odd-number law, Mersenne developed over the years the feeling that only the elaboration of a physical proof could provide sufficient confirmation of its validity. In the present article, I try to show that at the center of Mersenne's worries stood Galileo's assumption that a falling body had to pass in its acceleration through infinite degrees of speed. His extensive discussions with, or his reading of, Descartes, Gassendi, Baliani, Fabri, Cazre, Deschamps, Le Tenneur, Huygens, and Torricelli led Mersenne to believe that the hypothesis of a passage through infinite degrees of speed was incompatible with any mechanistic explanation of free fall.
This article analyzes Galileo’s mathematization of motion, focusing in particular on his use of geometrical diagrams. It argues that Galileo regarded his diagrams of acceleration not just as a complement to his mathematical demonstrations, but as a powerful heuristic tool. Galileo probably abandoned the wrong assumption of the proportionality between the degree of velocity and the space traversed in accelerated motion when he realized that it was impossible, on the basis of that hypothesis, to build a diagram of the law of fall. The article also shows how Galileo’s discussion of the paradoxes of infinity in the First Day of the Two New Sciences is meant to provide a visual solution to problems linked to the theory of acceleration presented in Day Three of the work. Finally, it explores the reasons why Cavalieri and Gassendi, although endorsing Galileo’s law of free fall, replaced Galileo’s diagrams of acceleration with alternative ones.
This article documents the general tendency of seventeenth-century natural philosophers, irrespective of whether they were atomists or anti-atomists, to regard space, time and matter as magnitudes having the same internal composition. It examines the way in which authors such as Fromondus, Basson, Sennert, Arriaga, Galileo, Magnen, Descartes, Gassendi, Charleton as well as the young Newton motivated their belief in the isomorphism of space, time and matter, and how this belief reflected on their views concerning the relation between geometry and physics. Special attention is paid to the fact that most of the authors mentioned above regarded rarefaction and condensation, on the one hand, and acceleration and deceleration, on the other hand, as analogous phenomena, which consequently had to be explained in similar terms.