The Dioptrique, often translated as the Optics or, more literally, as the Dioptrics is one of Descartes’ earliest works. Likely begun in the mid to late 1620’s, Descartes refers to it by name in a letter to Mersenne of 25 November 1630 III, 29). Its subject matter partially overlaps with Descartes’ more foundational project The World or Treatise on Light in which he offers a general mechanistic account of the universe including the formation, transmission, and reception of light. Although (...) Galileo’s condemnation by the Church prompted Descartes to abandon, in 1633, his plans for publishing The World, he continued in the ensuing years to vigorously pursue a number of scientific projects, including projects related to his work in optics. He was eventually persuaded to publish three essays highlighting some of his discoveries together with an introductory essay concerning “the method for rightly directing one’s reason and searching for truth in the sciences” . As one of those essays, Descartes’ Dioptrics finally appeared in print together with the Discourse on Method, the Meteorology and the Geometry in the summer of 1637 in a French language edition. It was republished in a Latin edition in 1644. The subject matter of the Dioptrics may be thought of as covering three main topics and is formally divided by Descartes into ten chapters or “discourses”. The first main topic concerns the nature of light and the laws of optics. In the first discourse, Descartes invites his readers to. (shrink)

The notion of representation figures centrally both in Descartes’ scientific theorizing about sense in humans and in his conceptual speculations about the nature of human cognition.Descartes’ philosophical innovation in the Dioptrics is the claim that sensing in humans is a kind of representing rather than a kind of resembling. This provides the cornerstone for his attack on traditional theories of sense, and it underwrites his own position that sensing is a kind of thinking, ascribable to the rational soul rather (...) than to any Aristotelean sensitive soul. (shrink)

The notion of representation figures centrally both in Descartes’ scientific theorizing about sense in humans and in his conceptual speculations about the nature of human cognition.Descartes’ philosophical innovation in the Dioptrics is the claim that sensing in humans is a kind of representing rather than a kind of resembling. This provides the cornerstone for his attack on traditional theories of sense, and it underwrites his own position that sensing is a kind of thinking, ascribable to the rational soul rather (...) than to any Aristotelean sensitive soul. (shrink)

This article seeks the origin, in the theories of Ibn al-Haytham (Alhazen), Descartes, and Berkeley, of two-stage theories of spatial perception, which hold that visual perception involves both an immediate representation of the proximal stimulus in a two-dimensional ‘‘sensory core’’ and also a subsequent perception of the three dimensional world. The works of Ibn al-Haytham, Descartes, and Berkeley already frame the major theoretical options that guided visual theory into the twentieth century. The field of visual perception was the first area (...) of what we now call psychology to apply mathematics, through geometrical models as used by Euclid, Ptolemy, Ibn al-Haytham, and Descartes (among others). The article shows that Kepler’s discovery of the retinal image, which revolutionized visual anatomy and entailed fundamental changes in visual physiology, did not alter the basic structure of theories of spatial vision. These changes in visual physiology are advanced especially in Descartes' Dioptrics and his L'Homme. Berkeley develops a radically empirist theory vision, according to which visual perception of depth is learned through associative processes that rely on the sense of touch. But Descartes and Berkeley share the assertion that there is a two-dimensional sensory core that is in principle available to consciousness. They also share the observation that we don't usually perceived this core, but find depth and distance to be phenomenally immediate, a point they struggle to accommodate theoretically. If our interpretation is correct, it was not a change in the theory of the psychology of vision that engendered the idea of a sensory core, but rather the introduction of the theory into a new metaphysical context. (shrink)

Descartes's Dioptrics is more than a mere technical treatise on optics; it is an essay in the "practical philosophy" that he claimed could render us "masters and possessors of nature." Descartes's practical intent is indicated first by the instrumentalist character of his derivation of the sine law of refraction, which is based on a heuristic and readily mathematizable model that requires no consideration of light's "true nature." Descartes's subsequent discussion of human vision is an extended critique of nature's workmanship (...) that grounds the possibility of improving vision by artificial means. I suggest that this critique is the source of Descartes's doctrine that the purpose of sensory perception is to preserve the mind-body composite, not to provide knowledge of the essential nature of things. Accordingly, the ultimate goal of the Dioptrics is to "master" human vision by raising it from a mere means of self-preservation to an instrument of scientific knowledge. -/- . (shrink)

Descartes is often thought to bifurcate sensory experience into two distinct cognitive components: the sensing of secondary qualities and the more or less intellectual perceiving of primary qualities. A closer examination of his analysis of sensory perception in the Sixth Replies and his treatment of sensory processing in the Dioptrics and Treatise on Man teIls a different story. I argue that Descartes offers a unified cognitive account of sensory experience according to which the senses and intellect operate together to (...) produce a fundamentally imagistic representation of the world in both its primary and secondary quality aspects. At stake here is not only our understanding of the cognitive structure of sensory experience but the relation of sense and intellect more generally in the Cartesian mind. The deep bifurcation in the Cartesian mind is not between the sensory perception of primary and secondary qualities but between sensory perception and purely intellectual perception. (shrink)

In the seventeenth century the new science was introduced through the works of Bacon, Hooke, Boyle, Power, and others. The advocates of the new science promised to divulge the inner workings of nature and to help man overcome his painful fallen state by means of controlling nature. The new sciences of mechanism and corpuscularism were to be based on objective experiments that would reveal the secret inner natures of minerals, vegetables, animals, the sun, moon, and stars. These experiments were done (...) with new and improved telescopes and microscope with magnifications of up to 100 times. One early critic of the new science was Margaret Cavendish. Cavendish was skeptical of the ambitious claims, methodology, instruments, and institutions of the new science. In her work, Observations Upon Experimental Philosophy, Cavendish argued against “experimental and dioptrical writers,” provided her own account of the natural world, investigated aspects of chemistry, medicine, and the nature of heat and color, as well as many other topics in natural philosophy (OEP 10). While many think Cavendish landed on the wrong side of history with respect to her skepticism regarding microscopes and telescopes, her criticisms of the new science were wide ranging and she was by no means the only one to question the value of such experiments and instruments. While several commentators, like Eve Keller (1997), have argued that Cavendish was against all things experimental, several recent commentators, Emma Wilkins (2014) and Deborah Boyle (2018), have tried to show the much more complicated relationship between Cavendish and the Royal Society and medical studies, respectively. In addition, some commentators, such as Lisa Sarasohn (1984, 2010) and Eve Keller (1997), have argued that Cavendish’s criticisms of the new science are based on her belief that Nature, as a representation of the feminine, was under attack by the experimentalists desire to “penetrate” and “manipulate” her for their own ends. While it is certainly true that Cavendish and many of the experimentalists personified nature as a woman, and that Cavendish does portray the men as trying to make her into something she is not, I agree with Deborah Boyle (2004) that these descriptions are not the focus of her objections to experimentalism. Rather than hold that Cavendish is concerned with, as Sarasohn claims, “the sexual implications for both women and nature of the new philosophy” (2010: 147), it seems that Cavendish’s objections were largely based on her philosophical commitments. However, I believe there is one aspect of the new science that Cavendish does critique from a feminist perspective, and that is what she sees as its institutional nature and its exclusion of women on the basis of sex, and to this I will turn in the last section of the chapter.1 My aim is to address Cavendish’s three major critiques of the new science. The chapter is divided as follows: The first section provides a brief overview of Cavendish’s views on the nature of bodies and perception. The second regards her critique of the methods and aims of the new science as represented by Bacon and Boyle. The third section examines her critique of Hooke and the instruments of experimentalism. The final section lays out her feminist critique of the institution of the new science. (shrink)

Descartes was disappointed with most of the Objections collected to accompany the Meditations in 1641, but he took a particularly dim view of the Third Set. ‘I am surprised that I have found not one valid argument in these objections,’ he wrote, close to the end of a series of curt and dismissive replies. The author of the objections was Thomas Hobbes. There was one other unfriendly exchange between Descartes and Hobbes in 1641. Descartes received through Mersenne some letters criticizing (...) theses in the Dioptrics, one of the Essays published with the Discourse on Method in 1637. Mersenne did not name Hobbes as the writer of the letters, attributing them to an unspecified Englishman, and it seems that Descartes never connected the critic of his optics with the author of the objections to his metaphysics. Nevertheless, Descartes responded with some hostility to the letters, angrily rebutting some points about refraction and charging that others had been appropriated from his own writings. Insinuating that the English correspondent was dishonest, Descartes decided to have no more to do with him. A meeting between the two men did take place in 1648 at a dinner given by the Marquis of Newcastle, but even on this occasion they did not see eye to eye, getting into an argument about the nature of hardness. (shrink)

My thesis is that Descartes wrote the Discours as a plan for a universal science, as he originally entitled it. I provide an interpretation of his letters that suggests that after Descartes began drafting his Dioptrics, he started developing a system that incorporated his early treatises from the 1630s: Les Méteores, Le Monde, L’Homme, and his 1629 Traité de métaphysique. I argue against the mosaic and autobiographic interpretations that claim these were independent treatises or stages in Descartes’ life. Rather, (...) I hold that threat of condemnation concerning his heliocentric thesis resulted in him suppressing his larger project and, instead, he published a plan where he outlined his ongoing system of philosophy. (shrink)

The aim of this paper is to account for Michel Henry’s critique of Merleau-Ponty as regards the own body and the flesh. To that end, I start by displaying Merleau-Ponty’s position on these matters. Then I present Henry’s critique, which are focused on Phenomenology of Perception and The Visible and the Invisible. After that, I consider these objections in general and concentrate on the meaning of Merleau-Ponty’s latest work on Descartes’ dioptric, in particular. Finally, I argue that his unfinished work (...) opens more fruitful channels of dialogue than the works criticized by Henry. (shrink)

Leibniz differs from Descartes insofar as he submits the search for mechanical explanations to regulatory norms. This is the case, for instance, in dioptrics: provided the law of sines is shown to conform to a sufficient reason of functionality, a relevant mechanical hypothesis is found acceptable. Explaining by means of hypotheses implies a twofold process of connections between an analytic model defining such an order of the elements as may fit the norm of a mathesis, and a presupposed mechanical (...) disposition of the elements such as may produce the constant effects revealed through experience. (shrink)

In the present work Berkeley's theory of vision is considered in its historical origins, in its relation to Berkeley's general philosophical conceptions, and in its early reception. Berkeley's theory replaces an account of vision according to which distance and other spatial properties are deduced from elementary data through an unconscious geometric inference. This account of vision in terms of "natural geometry" was first introduced by Descartes and Malebranche. Among Berkeley's immediate sources of knowledge of the geometric theory of perception, a (...) key role was played by the treatise of dioptrics of William Molyneux, Dioptrica Nova. Berkeley's understanding of "natural geometry" relies closely on Molyneux's description of the mechanism of vision which avoids the complexities of the accounts of Descartes and Malebranche. In the first chapter Berkeley's theory is presented by way of contrast with Molyneux's theory. In the second chapter I consider the relation between the theory of vision and immaterialism. In the final chapter I examine one of the first criticisms of Berkeley's theory, that which is found in William Porterfield's Treatise on the Eye. Dept. of Philosophy. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1997.G72. Source: Masterss International, Volume: 37-01, page: 0076. Adviser: John P. Wright. Thesis --University of Windsor, 1997. (shrink)

Descartes’s most extensive discussion of the law of refraction and the shape of the anaclastic lens is contained in Rule 8 of "Rules for the Direction of the Mind". Few reconstructions of Descartes’s discovery of the law of refraction take Rule 8 as their basis. In Rule 8, Descartes denies that the law of refraction can be discovered by purely mathematical means, and he requires that the law of refraction be deduced from physical principles about natural power or force, the (...) nature of the action of light, and the behavior of light rays in a variety of transparent media. For over a century, however, there has been broad agreement that Descartes discovered the law of refraction by purely mathematical means, and that he only later provided the relevant physical rationale (via comparisons or analogies) in Dioptrics II. I execute each step in Descartes’s proposed deduction of the law of refraction and the shape of the anaclastic lens in Rule 8 and concretely show how Descartes could have discovered the law of refraction and the shape of the anaclastic by its means. Rule 8, I argue, reflects Descartes’s actual path to the discovery of the law of refraction and the shape of the anaclastic lens. (shrink)

There is an uncanny unanimity about the founding role of Kepler's Dioptrice in the theory of optical instruments and for classical geometric optics generally. It has been argued, however, that for more than fifty years optical theory in general, and Dioptrice in particular, was irrelevant for the purposes of telescope making. This article explores the nature of Kepler's achievement in his Dioptrice . It aims to understand the Keplerian 'theory' of the telescope in its own terms, and particularly its links (...) to Kepler's theory of vision. It deals first with Kepler's way to circumvent his ignorance of the law of refraction, before turning to Kepler's explanations of why lenses magnify and invert vision. Next, it analyses Kepler's account of the properties of telescopes and his suggestions to improve their designs. The uses of experiments in Dioptrice , as well as the explicit and implicit references to della Porta's work that it contains, are also elucidated. Finally, it clarifies the status of Kepler's Dioptrice vis-à-vis , classical geometrical optics and presents evidence about its influence in treatises about the practice of telescope making during roughly the first two-thirds of the seventeenth century. (shrink)

RESUMENLa interpretación actual de la ciencia cartesiana ya no concibe ésta como una mera deducción desde los principios metafísicos, sino que reivindica el papel de la experiencia en ella. El presente artículo tratará de dar un paso más, defendiendo que existe una dimensión instrumental en la ciencia cartesiana. Para ello, se analizará la modificación que Descartes realiza en la Dióptrica de la relación artificial-natural y que posibilita una lectura instrumentalista.PALABRAS CLAVEDESCARTES, ARTIFICIAL, NATURAL, INSTRUMENTALISMO, CIENCIAABSTRACTThe current interpretation of the Cartesian science (...) no longer sees it as a mere deduction from the metaphysical principles, but claims the role of experience in it. This paper will try to go one step further, arguing that there is an instrumental dimension in the Cartesian science. With this purpose in mind, we will analyze the modification performed by Descartes in the Dioptrics regarding the artifitial-natural relation, which enables this instrumentalist reading.KEYWORDS DESCARTES, ARTIFICIAL, NATURAL, INSTRUMENTALISM, SCIENCE. (shrink)

Descartes' The World offers the most comprehensive vision of the nature of the world since Aristotle, and is crucial for an understanding of his later writings, in particular the Meditations and Principles of Philosophy. Above all, it provides an insight into how Descartes conceived of natural philosophy before he started to reformulate his doctrines in terms of a sceptically driven epistemology. Of its two parts, the Treatise on Light introduced the first comprehensive, quantitative version of a mechanistic natural philosophy, supplying (...) a theory of matter, a physical optics, and a cosmology. The Treatise on Man provided the first comprehensive mechanist physiology. This volume also includes translations of material important for an understanding of the work: related sections from the Dioptrics and the Meteors, and an English translation of the complete text of The Description of the Human Body. (shrink)

The article deals with the differences of pre-global and post-global conceptualizations in political sciences. It investigates the functions of political concepts under the changes globalization caused to political systems, culture and ideology. The paper does not engage with the methodological debates on political concepts, or question the undeniable importance of certain political concepts, but rather it addresses some of the principal concepts for which globalization may be a useful concept with regard to their similarities and differences with the Cold War (...) era. Despite the variety of political concepts as a result of various development phases of society, models of governance and ideological impact to the political processes along centuries, the concepts of power and authority seem to be among those that have survived in terms of the consistency of their relevance. However, the conception of politics through power, authority and leadership has been re-dimensioned significantly under the post-global era. By contrast, although the concept of sovereignty has been one of the initial concepts in the landscape of contemporary politics for many centuries back, following the effects of globalization, it has reduced its relevance significantly. In this view, as a consequence, the article discusses as well as the reconfiguration of the concept of state in a post-global era marked by a period of advancing causes—both trans-border and transnational causes—promoted by post-sovereignty states. Under these circumstances the traditional debate regarding conflict versus cooperation in politics is one of the areas remaining within a status quo dimension in the dioptric view of both pre-global and post-global conceptualizations. With a contrastive methodological approach, the article as well analyzes the development and meaning of the concepts of political equality, justice and liberty as indispensable concepts in modern post-global political processes. (shrink)

The doctrine of primary qualities is commonly explained as science's return to a former ideal of mathematical intelligibility and as a sacrifice of the notion that we can be certain about what we perceive. According to the standard chronicle modern scientific explanations appeal to geometrically intelligible, yet theoretically imperceptible, particles. This thesis gains plausibility only by suppressing the role of physiological optics in the development of modern science. Descartes presented an original and significant theory of scientific observation in his (...) class='Hi'>Dioptrics; according to which, correct perceptual judgments can be made about the spatial qualities of any body, even about bodies so small as to be imperceptible under ordinary circumstances. This theory insured the perceptual accessibility of the spatial qualities of minute bodies but failed, as Locke discovered upon adding solidity to the list of primary qualities, to explain access to non-spatial qualities. As a result of the failure of Descartes' theory of perception to give an adequate account of scientific observation, Locke took the position that solidity or impenetrability cannot ordinarily be perceived, but rather that it can be and is regularly detected by experiment. This Lockean shift from direct perceivability of spatial qualities to the experimental detection of "new" primary qualities marks an important step in the methodological development of early modern science. (shrink)

René Descartes, Discourse on Method, Optics, Geometry, and Meteorology. Trans., with an Introduction, by Paul J. Olscamp. Indianapolis: The Bobbs-Merrill Co., 1965. Pp. xxxvi + 361. = The Library of Liberal Arts, 211. Paper, $2.25. -/- From the notice in Journal of the History of Philosophy 5 (1967), 311: "In the introduction, Professor Olscamp calls attention to the fact that Descartes intended the other three pieces in this volume to serve as examples of the method set forth in the Discourse. (...) I t is only just that Descartes' intentions should now be fulfilled in fairly clear, if occasionally awkward English versions. Seeing these pieces brought together in this way also sheds light on Descartes' philosophical opinions, frequently distorted by over-simplified distinctions like that between empiricist and rationalist. 0lscamp succeeds in showing that Descartes is better thought of as a forerunner to modern-day hypothetico-deductive theories of scientific explanation. Perhaps it is what we should have realized all along in one so preoccupied with methodology. --A. R. Louch". (shrink)

This book covers a remarkable amount of ground and has become something of a classic. Besides the Discourse and the Meditations, it contains Private Thoughts, the third set of Objections and Replies, most of the Regulae, parts of the Principia and the Dioptrics, together with crrespondence with Elizabeth, Princess Palatine, Mersenne and others.