In the Optics, Descartes claims that telescopes and microscopes lead to morally certain knowledge. It is unclear, however, that Descartes’s expressed confidence in these instruments is warranted. In this article, I show how a limited range of telescope and microscope observations could lead to morally certain knowledge for Descartes, and how observations beyond this range admit of enough reasonable doubt to undermine moral certainty. I also explain moral certainty as a form of knowledge in Descartes’s scientific practices, his epistemic commitment (...) to optical instruments, and I offer an explanation for why Descartes never used optical instruments in his scientific endeavours. -/- ---- -/- Dans la Dioptrique, Descartes prétend que les télescopes et les microscopes donnent accès à des connaissances moralement certaines. Cependant, il n’est pas certain que la confiance accordée par Descartes à ces instruments soit justifiée. Dans cet article, je montre comment une gamme limitée d’observations effectuées à l’aide d’instruments d’optique pourraient mener aux connaissances moralement certaines pour Descartes, et comment d’autres observations allant au-delà de cette gamme introduisent suffisamment de doute raisonnable pour saper cette certitude morale. Enfin, j’interprète la certitude morale comme une forme de connaissance dans l’empirisme de Descartes, j’explique son engagement épistémique envers les instruments d’optique, et j’éclaire les raisons pour lesquelles il n’a jamais employé d’instruments d’optique dans ses propres recherches scientifiques. (shrink)

In response to widespread doubts among professional philosophers (Russell, Horwich, Dietrich, McGinn, Chalmers), Stoljar argues for a ‘reasonable optimism’ about progress in philosophy. He defends the large and surprising claim that ‘there is progress on all or reasonably many of the big questions.’ However, Stoljar’s caveats and admitted avoidance of historical evidence permits overlooking persistent controversies in philosophy of mind and cognitive science that are essentially unchanged since the 17th Century. Stoljar suggests that his claims are commonplace in philosophy departments (...) and, indeed, the evidence I adduce constitutes an indictment of the widely shared view among professional analytic philosophers. (shrink)

This paper presents a new approach to resolving an apparent tension in Descartes’ discussion of scientific theories and explanations in the Principles of Philosophy. On the one hand, Descartes repeatedly claims that any theories presented in science must be certain and indubitable. On the other hand, Descartes himself presents an astonishing number of speculative explanations of various scientific phenomena. In response to this tension, commentators have suggested that Descartes changed his mind about scientific theories having to be certain and indubitable, (...) that he lacked the conceptual resources to describe the appropriate epistemic attitude towards speculative theories, or that the presence of geometrical principles in these explanations guarantee their certainty. I argue that none of these responses is satisfactory and suggest a different resolution to the tension by examining Descartes’ notion of explanation. On Descartes’ view, providing an adequate explanation does not require being certain of the theories that constitute the explanans. Relatedly, the purpose of Cartesian explanations is not to discover the truth about the various underlying mechanisms that such explanations appeal to, but to support his general philosophical thesis that all natural phenomena can be explained by appealing to the extension of matter. (shrink)

In this article I dispute the claim, made by several contemporary scholars, that Spinoza was a naturalist. ‘Naturalism’ here refers to two distinct but related positions in contemporary philosophy. The first, ontological naturalism, is the view that everything that exists possesses a certain character permitting it to be defined as natural and prohibiting it from being defined as supernatural. I argue that the only definition of ontological naturalism that could be legitimately applied to Spinoza's philosophy is so unrestrictive as to (...) tell us nothing about the content of his ideas. The second, methodological naturalism, is the view that the natural sciences are the best means of finding out substantial truths about the concrete world. I present some historical research showing that Spinoza's way of positioning himself with respect to other philosophers in the Dutch Republic casts very serious doubt on the claim that he was a methodological naturalist. This adds further weight to arguments that have already been made against the naturalist reading of Spinoza. (shrink)

During the 1630s Descartes recognized that he could not expect all legitimate claims in natural science to meet the standard of absolute certainty. The realization resulted from a change in his physics, which itself arose not through methodological reflections, but through developments in his substantive metaphysical doctrines. Descartes discovered the metaphysical foundations of his physics in 1629-30; as a consequence, the style of explanation employed in his physical writings changed. His early methodological conceptions, as preserved in the Rules and sketched (...) in Part Two of the Discourse, pertained primarily to his early work in optics. By the early 1630s, Descartes was concerned with new methodological problems pertaining to the postulation of micro-mechanisms. Recognition of the need to employ a method of hypothesis led him to lower the standard of certainty required of particular explanations in his mature physics. (shrink)

ABSTRACT: The analytic method by which Descartes established the first principle of his philosophy is a unique cognitive process of direct insight and non-logical inference that differs markedly from the deductive model of noetic apprehension long associated with seventeenth-century rationalism. In this paper, it is shown that the same analytic process is at work in the Third Meditation proof of the innateness of the idea of God, where, however, there are serious doubts about its legitimacy.

Descartes is usually taken to be a strict reductionist, and he frequently describes his work in reductionist terms. This dissertation, however, makes the case that he is a nonreductionist in certain areas of his philosophy and natural philosophy. This might seem like simple inconsistency, or a mismatch between Descartes's ambitions and his achievements. I argue that here it is more than that: nonreductionism is compatible with his wider commitments, and allowing for irreducibles increases the explanatory power of his system. Moreover, (...) Descartes depends on nonreductionist knowledge and on irreducibles in order to maintain his epistemology and metaphysics. That is, there is more in the Cartesian world than mind, matter, and God. (shrink)

This journal article has been superseded by a revised version, published in the collection _Essays on the Philosophy and Science of Rene Descartes_, ed. by Stephen Voss (Oxford University Press, 1993), 259–287.

Descartes afirma que el cogito se "experimenta en uno" (apud se experiatur)o se "siente en uno mismo" ("il sent in lui-même"), pero también ha señalado que uno no siente sino a través del cuerpo. El problema es que, en las Meditaciones, el cogito fue caracterizado cuando todavía no se había demostrado la existencia del cuerpo. Pese a esto, Descartes parece haberse dejado influir por ciertas sensaciones internas de duda y certeza. En el trabajo se sostiene que esto fue posible porque (...) esas sensaciones internas son efecto de una ratio implícita: la existencia de un Dios no engañador. (shrink)

The ArgumentIn this paper it will be shown that Newton'sPrincipiagives an explication of and an argument for the first Law of Motion, that seems to be outside the scope of today's philosophy of science but was familiar to seventeenth-century commentators: The foundation of classical mechanics is possible only by recurrence to results of a successful technical practice. Laws of classical mechanics gain their meaning as well as their claims to validity only when considered as statements about artifacts whose production belongs (...) to the shared know-how of a scientific community. (shrink)

Focalisé sur un problème posé par Bernard Frenicle de Bessy vers 1639, sa solution et les réponses de ses correspondants, cet article s'attache à décrire plusieurs registres enchevêtrés de l'expérience du mathématicien: expérimentation sur les nombres empruntée en partie aux sciences de la nature, injonctions d'une pratique collective cimentée par les problèmes et leurs constructions explicites, entraînement personnel de l'attention et du savoir-faire s'articulent ainsi dans les efforts de Frenicle pour contester la suprématie de l'analyse algébrique et dans les modes (...) de conviction qui fondent son travail. Ce récit d'expérience permet en retour d'apprécier les problèmes que posèrent à Frenicle la transmission de ses résultats et, à ses historiens, la restitution de son activité. (shrink)