René Descartes (1596-1650) is a towering figure in the world of philosophy, widely recognized for his immense impact on modern thought. He revolutionized the fields of metaphysics, epistemology, and mathematics, introducing new perspectives and transforming the way we understand the world. Descartes’ legacy is inextricably linked to his famous maxim “Cogito, ergo sum”—“I think, therefore I am”—which has become a fundamental tenet of Western philosophy. His seminal works, such as Meditations on First Philosophy and Discourse on the Method, are still pored over by scholars across the globe, who continue to be inspired by his visionary ideas and profound intellect. Descartes’ enduring influence on modern philosophy and science is a testament to his exceptional brilliance and unwavering commitment to intellectual inquiry.
Roger Ariew is a Distinguished University Professor at the University of South Florida, specializing in the early modern period and the intersections between philosophy, science, and society. He has authored several books, including Descartes and the First Cartesians and Descartes and the Last Scholastics, as well as co-authored the Historical Dictionary of Descartes and Cartesian Philosophy. Ariew has also been awarded numerous fellowships and research grants by the National Endowment for the Humanities (NEH) and the National Science Foundation. He has directed three NEH Summer Seminars and is currently working on several projects, including an edition and translation of Descartes’ The World and Man and “The Complete Correspondence” in English Translation. Volume I of the latter, covering the years 1619-1638, is forthcoming from Oxford University Press.
Simply Charly: In what ways did Descartes’ interactions with scholastic philosophers influence his philosophical ideas and methodologies?
Roger Ariew: Descartes spent a considerable amount of time at the Jesuit College at La Flèche, where he underwent a rigorous curriculum spanning eight years. He immersed himself in the humanities for the first five years, focusing on French and Latin grammar, poetry, and rhetoric, and then moved on to the collegiate curriculum, which included logic, ethics, physics, and metaphysics, alongside mathematics. Although Descartes’ love for philosophy was greater than that for the humanities, he was dissatisfied with the courses in physics and metaphysics taught by the Jesuits, which were thoroughly Thomist in content. Despite this, Descartes did not fault his teachers, and in fact, sent copies of his Discourse on Method—a fruit whose seeds were sown in his mind by the Jesuits—to his teachers late in life. Descartes rejected Jesuit philosophy, which he understood thoroughly, and implicitly criticized various aspects of scholastic logic in his early works, constructing his own logic and method. He later went on to build a new physics and metaphysics, and even a different ethics. Although he did not read scholastic textbooks for roughly twenty years after leaving school, Descartes had to review them later to put himself in a position to respond to the expected objections to the Meditations, starting a new phase of his writing, resulting in the Principles of Philosophy, a more complete exposition of his metaphysics and physics in scholastic style, which even adopted some scholastic terminology.
SC: How did Descartes’ views on physics, specifically his concept of substance and the role of the laws of nature, differ from those of the scholastics?
RA: Descartes delved into the mathematical sciences, including optics, particularly dioptrics, which dealt with refraction. His physics was born out of his contemplation of optical phenomena, such as rainbows and false suns, which he explained as light rays reflected and refracted through moving particles. Consequently, he challenged Aristotle and the scholastics’ views on colors and sensations, rejecting their notion of universal hylomorphism—substance as a composite of matter and form, both substantial and accidental. Instead, he believed that natural phenomena could be explained without the need for forms. In his early physics book, Le Monde, he discussed how the external objects that produced sensations like color or pain could be interpreted as bits of extension, particles of different shapes and sizes in motion, and that the ideas formed in our minds need not resemble them. Descartes’ physics, as well as his account of the human body in L’Homme, were materialist and mechanist since he eliminated forms, thereby unifying the explanation of motion, locomotion, alteration, growth, and diminution. From his perspective, there was a contradiction in Aristotelian thought, where moving bodies were considered to be moved by something else and came to rest when not so moved, yet retained their qualities unless changed. Descartes’ first law of motion stated that each specific part of matter would remain in the same state unless colliding with other bodies caused a change. For instance, a body with a size would not become smaller unless divided by other bodies, and a round or square object would not change shape unless constrained by other bodies. A body at rest would not leave its place unless driven out by other bodies, and once in motion, it would continue to move with the same force until other bodies stopped or slowed it. Furthermore, Descartes clarified that each part of a moving body would tend to continue its motion in a straight line, even if the overall motion followed a curved path. Together, these rules were the first unpublished statement of the law of rectilinear inertia.
SC: How did Descartes’ concept of the self, as laid out in his famous statement “cogito, ergo sum,” shape his metaphysics?
RA: According to Descartes, the statement “I think, therefore I am” (or “‘I am, I exist’ is necessarily true every time I utter or conceive it in my mind,” as he puts it in the Meditations) is a truth that cannot be denied, even by skeptics. It is discovered through the method of doubt, which involves rejecting the senses as unreliable, making it a first truth of reason. However, what is even more significant is what follows immediately from the cogito: “sum res cogitans (I am a thinking thing).” This begins the process of distinguishing between the mind and the body, a process that takes up the rest of the Meditations. Descartes once confided to his primary correspondent, Marin Mersenne, that all the foundations of his physics are contained in his six Meditations, but he did not want this to be widely known, as he hoped that those who were partial to Aristotle would gradually become accustomed to his ideas and recognize their truth before realizing that they contradicted those of Aristotle. Descartes’ distinction between thinking things and extended things leaves no room for vegetative or animate souls in bodies, including human bodies, and requires the transfer of the traditional vital functions of the soul to the body, which are then explained mechanistically.
SC: Can you discuss Descartes’ views on the nature of the mind and its relationship to the body, and how they were received by his contemporaries?
RA: Pierre Gassendi raised questions that challenged Descartes’ explanation of how the soul, a non-material substance, could move the body and receive forms of corporeal objects. Princess Elisabeth of Bohemia and others further elaborated on this criticism. Descartes responded that such questions presuppose an explanation of the union between the soul and the body, which he had not yet addressed in the Meditations. He argued that the assumption that the soul and the body, being of different natures, cannot act on each other, is unprovable and false. Descartes also noted that even scholastics who admit the existence of real accidents such as heat and weight do not doubt that they can act on the body. He contended that there is actually more difference between accidents and a substance than between two substances. Despite this, such criticisms led to the development of various accounts of the relationship between mind and body, including occasionalism (Nicolas Malebranche, Pierre Sylvain Régis), parallelism (Baruch Spinoza), and pre-established harmony (G.W. Leibniz).
SC: Can you discuss Descartes’ influence on the development of modern mathematics, specifically the Cartesian coordinate system?
RA: Although I am not an expert in the history of mathematics, I believe I can shed some light on why Descartes is significant for modern mathematics. The Cartesian coordinates used today are not exactly the same as those developed by Descartes, but rather an elaboration of the method he used in the Geometry, which is one of the essays added to the Discourse on Method. However, Descartes is still credited with the idea because of his early work, the unfinished and posthumously published Rules for the Direction of the Mind (Ingenium), and the Geometry. The two-volume Latin-language second edition of the Discourse, translated and edited by Frans van Schooten in 1659-1661, also played a role in spreading the idea after Descartes’ death.
Descartes was able to make significant progress in understanding mathematics and optics in the Rules, but his main focus was to criticize philosophers who followed Aristotle and separated the sciences by their objects, and pursued them independently, neglecting the interconnectedness of different fields of knowledge. In particular, the Schoolmen treated physics and mathematics as separate subjects, with the former dealing with natural bodies and the latter with quantities and shapes as abstractions from bodies. Descartes believed that investigating the truth of things required an interdisciplinary approach, and this applied to mathematical sciences like geometry and arithmetic or algebra, which were also separated based on their objects. The Scholastics believed that geometry dealt with shapes and arithmetic with numbers, leading to the misconception that geometry was superior to arithmetic.
In contrast, Descartes proposed a universal mathematics, which would encompass all the parts of mathematics and explain everything that could be investigated concerning order and measure. The Geometry embodied this program, with its unification of algebra and geometry into a single subject. This was achieved by translating geometrical curves into algebraic equations with reference to some given straight-line segments. The idea of a Cartesian coordinate system can be traced back to Descartes’ solution to Pappus’ problem, which was suggested to him by the Dutch mathematician and philologist Jacob Golius in late 1631. In Book I of the Geometry, Descartes designated two line segments as unknowns, x and y, and known line segments as a, b, c, etc. The subsequent elaboration in the Geometry involved making the two line segments intersect at right angles. However, the most significant breakthrough was Descartes’ unification of geometry and algebra in what would later be called analytic geometry.
SC: How did the Cartesian group, also known as the Cartesians, interpret and build upon Descartes’ philosophical ideas in the seventeenth century?
RA: The Cartesians cannot be easily defined by a set of shared doctrines. However, they can be roughly divided into two groups that are not entirely distinct. The first group consists of those who either corrected Descartes’ ideas when they thought he was wrong or accepted some of his ideas as primary and modified others accordingly. Some of these Cartesians accepted atomism, despite Descartes’ argument that extension was infinitely divisible, and some believed that extended substance was as indestructible as mental substance. Others rejected interactive dualism and accepted occasionalism or changed the doctrine of the creation of eternal truths. Some abandoned the distinction between the infinite and indefinite, calling the universe infinite, and some modified Descartes’ laws of motion or rejected the pineal gland as the location of interaction between mind and body.
The second group attempted to expand Cartesianism to encompass the entire curriculum of the college. Although Descartes wrote the Principles of Philosophy as the beginning of this project, he recognized that a complete body of philosophy would need to explain the nature of minerals, plants, animals, and humans, as well as address medicine, morals, and mechanics. Therefore, the second group focused on constructing such views, completing Cartesian physics to include animals and humans, rounding out Cartesian metaphysics, and constructing Cartesian logic and ethics.
SC: How did Descartes’ ideas on the role of God in the natural world and the existence of an eternal and unchanging truth compare to those of the scholastics?
RA: Descartes tended to avoid subjects that required revealed theology, with only a few exceptions. Even when discussing topics such as the existence of God and the immortality of the soul, he saw himself solely as a philosopher, relying on natural light rather than supernatural light. In his Letter of Dedication, serving as a preface to the Meditations, he explained to the theologians of the Sorbonne that “I have always thought that two issues—namely, God and the soul—are chief among those that ought to be demonstrated with the aid of philosophy rather than theology.” Unlike scholastics and even modern thinkers like G. W. Leibniz, Descartes had reservations in mixing supernaturalistic explanations with naturalistic ones. However, on certain topics, such as eternal truths like mathematics, Descartes looked more like the scholastics, though he was more of a voluntarist than they were, since they typically considered these as coeternal with God. Descartes argued that God created the eternal truths, stating, “it is to speak of God as of a Jupiter or Saturn, and to subject him to the Styx and the Fates, to say that those truths are independent of him.” He began by asserting that the question did not seem to him to lie beyond philosophy, as it was metaphysical and could be examined by human reason, and then went on to argue that mathematical truths have been established by God and depend entirely on him.
The differences between Descartes and the scholastics were numerous, including the order of reasons that Descartes used in the Meditations. In Meditation II, Descartes began by supposing that everything he saw was false, that none of his memories represented anything that ever existed, and that his senses were unreliable. By doing this, he was able to establish the existence of himself as a thinking thing. In Meditation III, he sought to discover if there was anything else beyond these thoughts, such as a God who instilled these thoughts in him. Unlike the scholastics, who relied on other effects such as bodies in motion and efficient causation, Descartes could only rely on the thoughts themselves. Thus he based his proof of God’s existence from the effects on the idea of God.
In Meditation V, Descartes was able to use the previously established a criterion of truth, stating that clear and distinct ideas are true. His argument proceeded a priori and did not rely on any particular effect. This acceptance of an a priori argument was a point of difference between Descartes and the scholastics, who typically rejected such arguments. They argued that they could not have knowledge of God’s essence in this life from which they could argue for his existence.
SC: Can you discuss the criticisms that were levied against Descartes’ philosophy by his contemporaries and how he responded to them?
RA: At the end of the Discourse on Method, Descartes asked for his readers to send his publisher any objections they may have, promising to publish their objections and his replies. The response disappointed Descartes: it produced just a few sets of objections. Descartes replied to those letters and kept them in a special folder until the end of his life, but he did nothing further with them. When he published the Meditations, he arranged, mostly through his principal correspondent Marin Mersenne, to present his work to a select group of scholars before the official publication, so that their comments and his replies would be issued in a single volume with the Meditations. Six sets of objections were obtained and published in the first edition, together with Descartes’ replies; a seventh set by the Jesuit mathematician Pierre Bourdin followed in the second edition.
The first objections were penned by the Dutch priest Johan de Kater (Caterus), exemplifying Descartes’ intellectual relations to the scholastics of the time. Caterus focused on the theological aspects of Descartes’ metaphysics, and the discussion centered on five major topics: whether ideas require a formal cause for their existence, the positive self-causation of God, whether we possess the idea of an infinite being, the validity of the ontological argument for God’s existence, and the real distinction between mind and body.
The second and sixth objections, collected by Mersenne and written by various theologians and philosophers, placed Descartes directly in Mersenne’s circle and involved debates characteristic of the developing sciences of the time. These objections covered a wide range of issues, including the immortality of the soul and what we now call the Cartesian circle. The second set of objections also contained a request, perhaps inspired by astrologer Jean-Baptiste Morin, to present the contents of the Meditations in a geometrical fashion. This request led to Descartes producing an appendix titled “Arguments Proving the Existence of God and the Distinction of the Soul from the Body, Arranged in Geometrical Fashion.” This appendix arranged the Meditations with definitions, postulates, axioms or common notions, and propositions with their demonstrations in a geometric fashion.
The debate in the sixth set of objections revolved around topics such as the cogito, the kind of knowledge an atheist can possess, whether God can deceive, the status of eternal truths, and human freedom as indifference of judgment.
The third set of objections came from Thomas Hobbes, who is described as a “famous English philosopher.” Hobbes, along with Pierre Gassendi, a philosopher and historian who authored the fifth set of objections, had little sympathy for Cartesian doubt, which they considered exaggerated and a rehash of old arguments. Hobbes rejected Descartes’ method and dualism, insisting instead on the empirical basis of all our ideas and the dependence of the mind on the body. Descartes had little patience for these objections and his replies were sometimes sharp and personal. In fact, he said to Mersenne, “I think it would be best that I never have anything more to do with him [the Englishman]…for if his temperament is what I judge it to be, we would not be able to exchange views without becoming enemies.” The third and fifth sets of objections placed the Cartesian enterprise in relation to materialist or Epicurean movements of the day. Gassendi, though not a materialist, took this stance in his objections, referring to Descartes as “O Mind,” which led Descartes to call him “O Body.” The debate between Descartes and Gassendi was lengthy and contentious, and Descartes became angry with Gassendi when he published Disquisitio Metaphysica, a separate edition with rejoinders. For the French edition of the Meditations, Descartes asked his translator Claude Clerselier to omit Gassendi’s objections and to substitute instead a letter produced by his friends, in which he would answer a selection of Gassendi’s strongest arguments. The letter discussed standard objections against each Meditation, ending with what Descartes called “the objection of objections,” that everything we are able to understand and conceive is but imaginations and fictions of our mind that can have no subsistence.
The fourth set of objections came from Antoine Arnauld, a student of theology at Sorbonne. Descartes was pleased with Arnauld’s objections, considering them the best of all because he believed that Arnauld had a better understanding of what he had written than anyone else. This set of objections highlighted the deep relationship and differences between Descartes and the Augustinian tradition, which would soon become the Port-Royal group and “Jansenism” in general. The discussion revolved around various topics, such as the real distinction between mind and body and our knowledge of substances, the souls of animals, the material falsity of ideas, God as positively self-caused, the Cartesian circle, whether anything can be in the mind of which we are unaware, and the naturalistic explanation of the sacraments of the Eucharist. Of course, objections and replies on almost any philosophical issue continued after the publication of the Meditations and can be found in Descartes’ correspondence in abundance.
SC: How did Descartes’ views on the nature of reality, as entailed by his “evil demon” hypothesis, impact his metaphysics and epistemology?
RA: In 1630, Descartes wrote to Marin Mersenne expressing his belief that all those who have the gift of reason are obligated to use it to understand God and themselves. He revealed that he began his studies with this purpose in mind, referring to his Treatise on Metaphysics, which aimed to prove the existence of God and the immortality of the soul when separate from the body. Descartes claimed that he would not have been able to establish the foundations of physics had he not pursued this path. He also mentioned that he discovered a way to demonstrate the truths of metaphysics more clearly than the demonstrations of geometry. Although he worked exclusively on his metaphysical treatise during the first nine months of his stay in the Netherlands (i.e., most of 1629), he considered it inappropriate to publish it until he saw how his physics would be received. Descartes then spent the next three years focusing on his physics until he abandoned the project upon learning of Galileo’s condemnation for supporting the motion of the earth.
Descartes’ Treatise on Metaphysics did not survive, but when he published the Discourse on Method and wanted to discuss the parts of his physics that he thought were safe to publish, he needed to explain the metaphysics on which his physics was based. Therefore, in Part 4 of the Discourse, he referred to the first meditations he engaged in the Netherlands eight years earlier, saying that they were “so metaphysical and so out of the ordinary that perhaps they will not be to everyone’s liking.”
What Descartes revealed about his metaphysics in the Discourse must have been the content of the Treatise on Metaphysics or some development of it. In this work, Descartes decided to reject everything that he could imagine having the least doubt about, in order to determine whether something indubitable remained. He rejected the givens of the senses, all the reasonings he had previously taken for demonstrations, and pretended that everything that had ever entered his mind was no more true than the illusions of his dreams. This process led him to the realization of the truth “I think, therefore I am,” which he accepted as the first principle of the philosophy he was seeking.
Following this, Descartes argued that he knew he was a substance whose essence is to think. He derived a criterion of truth and used it to prove the existence of God, both from his idea of himself and as a geometric demonstration from the concept of God. All of this was done before he introduced the hypothesis of an evil demon or a deceiving God. Descartes developed his metaphysics separately from those two devices, which he seems to have needed in the “Meditations” to increase the doubt of the reader who would meditate with him to an even greater degree than in the “Discourse.”
It is not clear whether the evil demon hypothesis does much more to increase the natural doubt of the Discourse to the hyperbolic doubt of the Meditations, but the deceiving God hypothesis appears to increase that doubt to the very edge of incoherence. It seems to have been abandoned, even if temporarily, for the evil demon hypothesis.
SC: How did Descartes’ views on the nature of consciousness and the mind-body problem anticipate and influence later philosophical debates on these topics?
RA: To appreciate the impact of Descartes’ views on consciousness, one must recognize the significant intellectual shift that Descartes was asking his audience to undertake. The response to Descartes’ Discourse on Method by Libertus Fromondus, a Professor of Philosophy and then Theology at Leuven University, provides an example of this point. Fromondus was a noteworthy scholar, an Aristotelian philosopher who was not hesitant to criticize Aristotle, and a Catholic theologian who played a significant role in the publication of Cornelius Jansen’s Augustinus (which gave rise to the Jansenist movement). At the beginning of his career, Fromondus published a record of some observations he had made on the comet of 1618, concluding, against Aristotle, that it was not a fiery exhalation in the air, but something similar to a planet, located beyond the moon. Fromondus subsequently published a Meteorology which included his explanation of comets and even challenged Galileo’s account of comets as terrestrial exhalations. Descartes was aware of Fromondus’ Meteorology, and thus sent him a copy of the Discourse, along with its appended essay Meteors.
Fromondus’ response to the Discourse was critical, with him deeming Descartes’ physics as crude and crass. He found it astonishing that anyone would want to explain natural phenomena in a mechanistic manner rather than relying on form and real qualities. Fromondus doubted that heat alone could accomplish all the operations of an animal in a human body, and he didn’t think that noble actions such as vision could result from such an ignoble and brute cause as heat. He found it paradoxical that the same corpuscles could create a sensation of cold with a light impact on the sense of touch and one of heat with a more forceful impact, “as if differences only existed between the local impact, rather than in the qualities affecting the organ of touch in different ways!” He argued that when an animal is burned on some part of its body, there must be some operation of touch that makes the animal perceive a dolorific quality there, which Descartes did not seem to recognize. Additionally, Fromondus stated that Descartes hoped to explain too many things with position or local motion alone, but other real qualities were required for an explanation. Fromondus’ bewilderment appeared to stem from trying to understand a different, incommensurable worldview.
Descartes responded to Fromondus’ criticism, acknowledging that his philosophy may seem crude to some because it focused only on shapes, magnitudes, and motions, like mechanics. However, he explained that this was precisely what he believed to be the most praiseworthy aspect of his philosophy, and what he was most proud of. In regards to touch, Descartes challenged Fromondus by suggesting that it was equally paradoxical that a light rubbing on the hand could produce a sensation of pleasure and a harder rubbing could produce a sensation of pain. And in response to Fromondus’ complaint about his not recognizing any sensation but what took place in the brain, Descartes referred to the experience of physicians and surgeons who knew that amputees often continued to feel pain in limbs they no longer had. Descartes believed that this could only happen if the sense of pain, or sensation, took place in the brain.
As readers on the other side of the Fromondus-Descartes divide, we agree with Descartes and see no need for substantial forms and real qualities to explain vision, touch, taste, or pain, as we understand phenomena such as phantom limb pain.
SC: Can you discuss Descartes’ contributions to the field of natural science and his role in the Scientific Revolution?
RA: The contributions Descartes made to the natural sciences are too numerous to count. As we have already mentioned, he made groundbreaking discoveries in refraction and the law of sines, laws of motion, and the unification of mathematics and sciences, utilizing Cartesian coordinates and inventing analytic geometry. Additionally, he proposed that sensations were mental phenomena and sought to explain all natural phenomena through mechanical means. While some argue that this move represents his lasting contribution to the Scientific Revolution (referred to as the mechanization of mathematization of nature), this view seems anachronistic. In the seventeenth century, Descartes’ program of establishing physics on metaphysics was considered highly innovative by his followers. But this did not need to yield a mathematical physics: depending on the specific metaphysics on which the sciences were based, either mechanistic or mathematical sciences could follow. Descartes argued for certain general principles of physics based on his metaphysics, but he also utilized hypotheses to explain particular phenomena. He considered these hypotheses morally certain when they were few and had great explanatory power. Ultimately, many Cartesians, regardless of whether they thought the principles of physics were based on metaphysics, considered the method of science to be hypothetical-deductive, like Descartes’ morally certain hypotheses. The seventeenth and eighteenth-century debates about scientific methodology centered on whether the hypothetical-deductive method needed to be limited to hypotheses consistent with “intelligible” first principles, as the Cartesians believed, or be more liberal with hypotheses to the point of eliminating them entirely, as the Newtonians advocated.
SC: Can you discuss the lasting impact of Descartes’ philosophy on Western thought and its relevance today?
RA: Descartes’ significance for the seventeenth century cannot be overstated. He had many devoted followers during his lifetime. In 1654, just four years after his death, Jacques Du Roure published a two-volume textbook in Paris containing all the parts of philosophy, including logic, metaphysics, physics, and ethics. The volume was said to contain ancient and new authors, including the Peripatetics and Descartes. Although Du Roure had not met Descartes, he included testimonials on the reverse side of his title page from the first generation of Cartesians. For example, Tobias Andreae, Professor of History at the University of Groningen, wrote that “Descartes is the premier Philosopher of all times,” and Johannes Clauberg, Professor of Philosophy at the University of Duisburg, stated that “After the Sacred Books, there are none I esteem more than those of the illustrious Descartes.”
However, Descartes’ ideas also drew opposition from authorities who grew weary of its popularity. While Descartes was alive, there were official condemnations by Protestants at Utrecht and Leyden Universities. After his death in 1650, the battles intensified. There were condemnations by Catholics at Louvain in 1662, and Descartes’ works were eventually put on the Index of Prohibited Books by the censors of Rome in 1663. In the second half of the seventeenth century, the dispute continued with numerous attacks in print, and the Cartesians counterattacked with satires and essays. The anti-Cartesians also responded with their own satires, and the dispute spilled into the official political arena of the king, the universities, and the teaching orders. In 1671, the king issued an edict against teaching Cartesian philosophy, and the faculty of arts at Paris condemned it in 1671 and succeeded in 1691. Skirmishes occurred at Angers and Caen during 1675-1678, with professors who were allegedly teaching Cartesian philosophy being expelled. The Oratorians ultimately prohibited the teaching of Cartesianism in 1678, and the Jesuits formally condemned it in 1706.
In the context of numerous condemnations and resulting censorship, it might seem surprising that the Cartesians, who had lost many battles, ultimately won the war. By 1720, the fundamentals of Cartesian physics were definitively accepted, with Cartesian mechanism becoming the approved physical philosophy at the University of Paris. The victory of Cartesianism over Scholasticism was so complete that by 1734, Voltaire famously wrote, “A Frenchman, who arrives in London, will find philosophy, like everything else, very much changed there. He had left the world a plenum, and he now finds it a vacuum. At Paris the universe is seen composed of vortices of subtle matter; but nothing like it is seen in London. In France, it is the pressure of the moon that causes the tides; but in England it is the sea that gravitates toward the moon.” Although Voltaire’s account of Paris as a Cartesian stronghold and of London as a Newtonian one pitted these philosophies against each other to the benefit of the Newtonians, it was also clear that the battles were no longer being waged between Cartesians and Scholastics, as the latter had dropped out of the contest.
Descartes and the Cartesians developed philosophical systems that they believed were at odds with those of the scholastics. However, many philosophers in the next generation saw themselves as drawing from both scholastic and Cartesian doctrines, as well as other options like Pierre Gassendi’s neo-Epicureanism. In the third or fourth generation, debates centered on the opposition between rationalists and empiricists, with Descartes, John Locke, and David Hume as key figures. In natural philosophy, the main opposition was thought to be between the (rationalist) Cartesians and the (empiricist) Newtonians. When Immanuel Kant was weighing his philosophical options, his universe consisted mainly of the philosophies of G. W. Leibniz, Newton, Descartes, and Hume. And when he referred to “school metaphysics,” the scholastic philosophy he had in mind was not that of the Aristotelians, but that of Christian Wolff. There have been revivals of Cartesian philosophy at later times that have played a role in various debates, but often in these instances the image of Descartes becomes distorted, a caricature removed from its context, simply to be attacked and refuted.
PAINTING OF DESCARTES: Kurt Smith