As sociologists learn more about how scientific knowledge is created, they give historians the opportunity to rework their accounts from a more contextual perspective. It is relatively easy to do so in areas with large theoretical, cosmological or overtly ideological components. It is more difficult, but equally necessary, to open up very empirical accomplishments, and recent sociological analysis of the process of science gives us some interesting insights. This paper employs some of these on the apparently unpromising subject of the (...) ‘discovery of secular magnetic variation’ in 1634 by the Gresham professor Henry Gellibrand. (shrink)

This contribution explores Gilles Personne de Roberval’s 1644 Aristarchi Samii de mundi systemate, partibus, & motibus eiusdem, libellus. I focus on the complex circumstances of publication, the intellectual context of the polemics of Copernicanism within the scientific community, as well as the natural philosophy of the treatise. Roberval’s strategy of publication provides a very sophisticated example of authorship in early modern natural philosophy. The strategy lies at the conflux of certain specific motivations. I contextualize these motivations by accounting for the (...) delicate debates around the motion of the Earth in mid-seventeenth century Europe, the institutional communities of the Collège Royal and Mersenne’s circle, and the disciplinary bounds of Roberval’s professional authority. Weighing in all the elements, I argue that Roberval’s publication is an interesting intellectual game, playing with the notion of ancient authority and humanistic recovery. By this somewhat libertine attitude, Roberval takes a stance in a complicated debate around heliocentrism and the status of hypothetical cosmology. Roberval’s position is supported by his natural philosophical speculations, which I situate in the contemporary debates of the community. Roberval borrows from many philosophers, but he aims at achieving a highly systematic speculative cosmology. One of the functions of this system is to confirm Copernicanism, while maintaining a very pessimistic attitude on the prospects of precise astronomical knowledge and, among others, prognostication issues. (shrink)

In the ten years following the publication of Galileo Galilei's Discorsi e dimostrazioni matematiche intorno a due nuove scienze , the new science of motion was intensely debated in Italy, France and northern Europe. Although Galileo's theories were interpreted and reworked in a variety of ways, it is possible to identify some crucial issues on which the attention of natural philosophers converged, namely the possibility of complementing Galileo's theory of natural acceleration with a physical explanation of gravity; the legitimacy of (...) Galileo's methods of proof and of his theory of the composition of continuous magnitudes; and the adequacy of the experimental evidence in favor of his theory.Through his published works and his correspondence, Marin Mersenne contributed in a significant way to each of these discussions. In the following, I shall provide a sketch of Mersenne's multiple engagement with the new science of motion, while trying to account for his growing skepticism concerning Galileo's law of free fall. Whereas in the 1630s, Mersenne still firmly believed in the validity of this law and tried to devise experimental and mathematical proofs in its favor, in the 1640s he developed serious doubts regarding the possibility of constructing an exact science of motion. As we shall see, Mersenne's evolving attitude sheds an interesting light on his views concerning the relation between physics and mathematics.---------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- ----------------------------------------------------. (shrink)

Resumen La naturaleza de las entidades matemáticas ha sido un problema filosófico recurrente en diversas épocas; aquí mostraré que fue una pieza clave en la definición de las posturas ontológicas durante la Modernidad temprana. La piedra de toque para la fundamentación de los conocimientos científicos fue el carácter que se atribuyó a las entidades matemáticas -y, en general, a las entidades abstractas, incluidas las lógicas- en la filosofía natural. Expongo dos posiciones de la Modernidad: la que defendió René Descartes, quien (...) las concibió como entidades perennes, inherentes a la propia constitución y funcionamiento de la mente y la de autores como Pierre Gassendi y Marin Mersenne, quienes defendieron el origen empírico e instrumental de esas entidades.The status of mathematical entities has been a recurrent philosophical problem in different times; here I explain how it was a key piece in the definition of ontological positions during Early Modernity. The touchstone for the foundation of scientific knowledge was the character assigned to mathematical entities -and, in general, to abstract entities, including logical ones- within the natural philosophy. I sketch two modern positions: on the one hand, the one defended by René Descartes, who assigned mathematical items a status of perennial entities, inherent to the very constitution and operation of the mind and, on the other, the one supported by authors such as Pierre Gassendi and Marin Mersenne, who defended the empirical and instrumental origin of those entities. (shrink)