O objetivo deste artigo é provar que a experiência tem um papel central na ciência cartesiana e que, portanto, Descartes está disposto a abandonar alguns pressupostos teóricos para adequar-se a algumas observações científicas. Meu ponto é que o compromisso de Descartes com as observações científicas é tão forte que, no estudo do magnetismo, ele opta pela inconsistência do seu sistema quando adota uma propriedade do magnetismo que contraria a lei da conservação da quantidade de movimento. Ou seja, mostrarei que Descartes (...) acata uma propriedade do ímã, observada por vários cientistas, especialmente Gilbert, que é contrária à lei da conservação da quantidade de movimento para resguardar uma sintonia com as observações empíricas. Esse compromisso com a experiência reforça a imagem de que Descartes não era indiferente às observações empíricas do seu tempo, mas opera uma ciência que tenta adequar-se a elas. This article sets out to prove that experience plays a central role in Cartesian science and, therefore, that Descartes is willing to let go of some theoretical assumptions in order to accommodate scientific observations. My point is that Descartes' commitment to scientific observation is so strong that in the study of magnetism, he chooses not to keep his system not completely consistent when he adopts a magnetic property (a property that was observed by several scientists, especially Gilbert) that contradicts the law of conservation of quantity of motion in order to keep in touch with empirical observations. This commitment to experience further strengthens the notion that Descartes was not indifferent to the empirical observations of his time, and actually engages in scientific work that tries to adapt itself to them. (shrink)

This article examines the relationship between blindness and the Enlightenment concept of the system, arguing that blindness is used as a weapon to discredit 17th-century metaphysics, as well as a tool through which thought can take shape or even systematize itself apart from dogmatism. Philosophers use blindness metaphorically, thus equating systematics within the obscurity of ignorance; yet, with Diderot, they also demonstrate that philosophy, for better or for worse, is literally an affair of blindness.

This paper discusses the problem of sensible qualities, an important, but underestimated topic in Leibniz's epistemology. In the first section, the confused character of sensible ideas is considered. Produced by the sensation alone, ideas of sensible qualities cannot be part of distinct descriptions of bodies. This is why Leibniz proposes to resolve sensible qualities by means of primary or mechanical qualities, a thesis which is analysed in the second section. Here, I discuss his conception of nominal definitions as distinct empirical (...) representations. The provisional and modifiable status of nominal definitions is then explained in the third section. Since nominal descriptions always contain sensible determinations, Leibniz claims that empirical knowledge is indefinitely changeable according to progress in sciences. In the final section, I address the criterion of coherence that enables us to approve of hypotheses that are based on both sensible and empirical properties. (shrink)

À travers l'analyse de la correspondance entre Leibniz et Wolff, l'article cherche à restituer les modalités démonstratives utilisées par Leibniz pour transmettre sa dynamique ainsi que le dispositif métaphysique qui lui est inhérent. Il est question ici de l'ambivalence du vocable d'action, à la fois objet du principe de conservation et essence de la substance. C'est en étudiant sa réception par Wolff qu'il est possible de mettre en évidence, dès 1705, la singularité d'un cadre métaphysique wolffien qui accueille la dynamique (...) leibnizienne de l'action, puis la publicise, tout en proposant une acception irréductiblement différente de la substance. (shrink)

Leibniz’s ‘new science of dynamics’ is typically taken to have been completed in the late monadological metaphysics. On this view, stemming from Martial Gueroult and continuing in the recent interpretations of Robert Adams and Pauline Phemister, Leibniz accomplished his dynamics in his later account of physical forces as merely phenomenal modifications of monadic, metaphysical forces. This paper argues, by contrast, that Leibniz considered the dynamics to be an unfinished project: this is evident in statements from throughout his mature period until (...) his final months. Two possible reasons for the non-completion of the dynamics are discussed. The first is that his encounter with the superior physics of Newton’s Principia caused Leibniz to continually defer his own contribution. I argue, however, in favour of a second reason: that there are philosophical difficulties inherent in the science of dynamics that prevented its completion. These difficulties are found in the relation of dynamics to metaphysics, and in the more fundamental split within dynamics, into the doctrine of primitive and derivative forces. Through three late exchanges with de Volder, Wolff and Des Bosses, I show that the relation of primitive and derivative forces remained an unsolved – although not in principle unsolvable – problem for Leibniz. (shrink)

Neste artigo, pretende-se indicar como o jovem Leibniz, em textos do início da década de 1670, como no Theoria Motusi e nas correspondências a Johann Friedrich e a Hobbes, apropria-se do conceito de conatus e da teoria da sensação de Hobbes para defender a existência de mentes incorpóreas, seres verdadeiramente indivisíveis, em oposição à redução hobbesiana da realidade a corpos e seus movimentos. Ademais, uma vez que a essência do corpo reside no movimento e não na extensão — como o (...) filósofo afirma influenciado pelas teorias de Hobbes — e que o corpo, de acordo com os princípios do mecanicismo, não é fonte de seu próprio movimento, Leibniz argumentará que a sua substância deve residir em algo incorpóreo. Essa apropriação por parte de Leibniz do conceito de conatus e da teoria do movimento hobbesianos desempenhará, assim, um papel importante não apenas na rejeição da substância extensa cartesiana, como também na posterior reabilitação das formas substanciais, rejeitadas pelo autor na sua primeira juventude. (shrink)