Han van Ruler © 2021

Over the last half a century or so, René Descartes (1596-1650) has gradually lost his one-time status as a philosopher whose work merits serious and continued scholarly interest. The NWO-funded research project Decoding Descartes, launched at Erasmus School of Philosophy (ESPhil), Erasmus University Rotterdam, in January 2020, is meant to change this, and to contribute to a reappraisal of the philosopher and his works. Amongst other things, Decoding Descartes will result in a new, critical edition of Descartes’ vast corres­pon­dence to be published with Oxford University Press. Descartes’ letters and the letters others addressed to him are a gold mine in themselves for the study of seventeenth-century European intellectual history, but besides the work on the correspondence, Decoding Descartes also has a substantive part on Descartes’ philosophy. This part of the project aims not only to rehabilitate the philosopher and to address the many misconceptions that have tinged his reputation, but also to explain why it is as important as ever to assign to Descartes a central role in philosophical history as well as in present philosophical, scientific and public debate. What follows is an early taster for this theoretical part of our project.

The Need for a New Descartes

More and more historians and philosophers are presently becoming aware that the caricature, twentieth-century image of René Descartes no longer holds. In both the analytical and continental traditions, academics are starting to acknowledge that Descartes was not the metaphysical thinker primarily concerned with offering theories about God and the soul, but presented himself primarily as a scientist and as a philosopher of the body, drawing attention to human emotional life as well as to the need for getting to grips with psychosomatic phenomena in new, scientific ways. As a consequence, more and more scholars are starting to notice the historical inaccuracy of the concept of ‘Cartesian dualism’.

There is, however, still a lot to be done. In a recent article on ‘The embodied Descartes’, Barnaby Hutchins, Christoffer Basse and Charles Wolfe have argued a new “reading of Descartes” is emerging especially “from recent scholarship on L’homme.”[1] In fact, the article itself occurs in an edited volume of studies on L’homme that marks the renewed interest in this work. The Traité de l’homme (or ‘Treatise on Man’) is an early treatise by Descartes on human physiology. The book was never published during the philosopher’s lifetime, but already caused a stir back in the 1660s, when Descartes’ star was rising ever faster with the rediscovery of L’homme, and it became clear that the author of the Meditations and the Principia had already developed a complete biological description of human beings that could serve as a background for his work on the emotions and other themes of psychosomatic interest. 

What we are thus witnessing today is a something of a repetition on a global scale of what once occurred on the streets of Leiden and Paris, when people started to realise what Descartes had really been on about. I have previously had the privilege of writing about this ‘other Descartes’ in my introductory chapter to the Oxford Handbook of Descartes and Cartesianism in 2019.[2] The story of the alternative Descartes goes somewhat like this: contrary to the textbook image we are all acquainted with, the historical Descartes was not at all the metaphysical thinker a superficial reading of his most popular works may seem to suggest. Neither was he the ‘dualist’ that many philosophers after him used — and still use — as a straw man in order to define their own — often in fact rather ‘Cartesian’ — positions. In contrast to this cliché-Descartes, the historical Descartes was a philosophically inclined natural scientist, whose contribution to science lay not so much in formulating natural laws (which, incidentally, he also did – in fact, he invented the notion of such laws), but in philosophically paving the way for science. Descartes showed the way to scientific investigation by indicating how one could think about man as a biological being without making any use of the notion of the ‘soul’ and how one could think about natural processes without using concepts such as ‘substance’, ‘form’ or ‘substantial form’.

At present, this is a message that has yet to land in the world of philosophy and science. A large number of authors in the fields of neurophysiology, cognition theory and philosophy, continue to accuse Descartes of having somehow introduced the distinction of body and soul — a distinction Descartes could never have introduced, if only for the fact that it is a distinction that has no doubt been made in every culture since human beings started to express themselves in language. Nevertheless, claiming to adjust an erroneous attempt in Descartes to link the body to the mind, philosophers as well as scientists have had a tendency to go about doing exactly the kind of things Descartes had already been doing himself almost four centuries ago.

Decoding Descartes aims to rehabilitate Descartes by providing a solid historical reconstruction of the context in which he operated. What is new in this research project, is that we will try to uncover Descartes’ own philosophical motivations by interpreting his thinking from the perspective of his intellectual background: why did he actually say and do what he did? On the basis of an answer to this question, we aim to gain a better insight into the nature of the intellectual turn that Descartes brought about, and to indicate its continued relevance to philosophical and scientific thinking.

Critical Rehabilitation

Probably the most widespread misconception about Descartes stems from the Kantian divide between ‘rationalism’ and ‘empiricism’ — a point to which we will return below. A close second in spreading persistent misconceptions about Descartes — at least within the analytic tradition in Western philosophy — is Gilbert Ryle’s famous critique of Descartes in The Concept of Mind (1949). Ryle’s view still lives on in the work of countless others through such persistent memes as ‘The Cartesian Myth of the Ghost in the Machine’ and the unhelpful idea that Descartes committed what Ryle called a ‘category mistake’.

Ryle’s own big mistake was that, by arguing that the human mind should not itself be reified into an object of enquiry, he was doing exactly what the real Descartes himself had been trying to get across to his own, seventeenth-century, audience. Acknowledging the fact that Descartes was facing this same problem, we should equally acknowledge that Descartes was not just prefiguring Gilbert Ryle on this account, but must also count as the precursor of Hume, Kant, Sartre, Wittgenstein and many other philosophers besides.

For a while I thought I was the only one who saw things quite this way, but last year Rodney Ramdas, a master’s student of ours at ESPhil, pointed out to me that Ian Hacking had already come to the same conclusion and that there was in fact a whole series of feminist thinkers (including Sara Heinämaa, recently a keynote at the annual Dutch OZSW conference), who have been claiming similar things for decades. It was in this way that I discovered the work of Lilly Alanen, who already in 1989 pointed out that, under the influence of Ryle, analytic philosophy collectively suffered from the “Myth of the Cartesian Myth.”[3] That Myth, however, is still everywhere present today. In 2005, Ian Hacking also thought he was more or less alone in questioning the Myth. Not without a sense of drama, Hacking accordingly described his position as an iconoclasm:

My iconoclasm is to suggest that Descartes’s final response to the princess Elisabeth was to say much the same thing as Ryle, [only] in the barely worked out idioms of an earlier age.[4]

So much for Ryle and analytical philosophy. Misconceptions about Descartes are not limited to analytic philosophy, however. Since 1994, I have myself time and again repeated that the Portuguese-American neuroscientist Antonio Damasio is himself a Cartesian, despite the fact that he viewed everything he did to be a correction of Descartes’s Error — the unfortunate title of his 1994 book. When Damasio came up with the idea in 2010 that human self-experience was not just about emotions, but that human consciousness might also be important for understanding humans, he wrote the following:

Conscious reflection and planning of action introduce new possibilities in the governance of life over and above automated homeostasis, in a remarkable novelty of physiology. Conscious reflection can even question and modulate automated homeostasis and decide on an optional range of homeostasis at a higher level than needed for survival and more consistently conducive to well-being. The imagined, dreamed-of, anticipated well-being has become an active motivator of human action. Socio-cultural homeostasis was added on as a new functional layer of life management, but biological homeostasis remained.[5]

Freely translated: in addition to their primary reactions, human beings also have the opportunity to think about these reactions and to adjust them. These words were formulated in 2010, but what Damasio has to say here is in part a repetition of ancient Greek moral philosophical insights — and partly pure Descartes. More importantly, it is a blatant acceptance of what Descartes is always being accused of: dualism.

It is not that I do not like Damasio’s work; I love it, just as I love the work of Daniel Dennett, whose life — by his own admission — has more or less been dedicated to the question of overcoming Descartes.[6] In Dennett, too, we see Descartes returning at crucial steps of the argument, for example in Dennett’s defence of free will, in which the two core aspects of ‘decision making’ and ‘training’ are in fact a reiteration of what Descartes had already put forward in his Passions de l’Âme of 1649, even if Dennett interprets the position of his opponents as ‘Cartesian’, and even if Descartes himself did not refer to tennis, but more generally to the regulation of one’s emotions.[7] And in Dennett, too, we thus encounter an unmistakable manifestation of ‘dualism’ in the ‘distribution’ of the various types of ‘work done’ by the agent.

Cognitive science does not fare much better. Francisco Varela, Evan Thompson and Eleanor Rosch have hurled philosophical swear words such as ‘representation’, ‘Ego-Self’ and ‘Cartesian Anxiety’ at Descartes — and not at just Descartes, but at all of his supposed followers in the West.[8] Meanwhile, as an alternative, they came up with ideas about the embodied self, about why we do not coincide with our brains (again: dualism!), and with new biological explanations of consciousness that form a complex of positions each of which has its historical background in Descartes’ Dioptrics (1637), Meditations (1641) and Passions of the Soul (1649).

What is behind all of these misconceptions? The problem, every time, is that philosophers, neuroscientists, and cognitive theorists alike keep confronting Descartes with the metaphysical questions that Descartes himself was trying to avoid and banish from natural-philosophical investigation. This is also reflected in the continental reception of Descartes, in which the latter’s philosophy is read as something of a variation on Aristotle. Descartes may have come up with a new philosophy, but, according to this view, it was still a philosophy not much different from the philosophy that went before, in as much as it still depended on an ‘essentialist’ ontology. Change would come only with Spinoza and Leibniz, who, at least according to present-day Critical Theory, came forward with the idea of ​​a new, “modal” type of metaphysics; a metaphysics that might still inspire us.

To see what is wrong with this view, there is no need to enter into a sophisticated analysis of Spinoza’s or Leibniz’s views on substances and modes. What suffices, is to take a closer look at what actually drove Descartes.

Lasting relevance

Gilbert Ryle’s critique on Descartes would be better applied to Spinoza and Leibniz. The Verdinglichung, or reification, of the subject that Ryle wrongly attributed to Descartes can indeed be found in Leibniz, who, in the wake of Descartes, tried to revive the idea of ​​individual substances by introducing the notion of ​​metaphysical ‘monads’. Spinoza reified all of reality in one go: everything in fact made up a single ‘substance’. Both Leibniz and Spinoza had good meta-philosophical reasons for reintroducing such metaphysical concepts. Spinoza benefitted from the reification of the whole of reality by playing his Protestant tune of spiritual salvation on the metaphysical instrument of a complete necessitarianism, thus being able to show that even in the age of science, one might still find security in God’s hands. Leibniz made use of his own particular type of reification by allowing all things to take their own course, thereby absolving God of any responsibility for evil — but also portraying him as a somewhat naive logician-annex-juggler in the design of the universe.

Why Descartes distinguished himself and makes a difference here, is because he no longer made use of the concept of the mind in order to make metaphysical claims, just as he no longer found it meaningful to attach qualities to things that are derived only from mentally experiencing them. What he did, in other words, was to stop looking for metaphysical entities in reality. Descartes was already convinced, early on in his life, that our sense-experience brings with it a host of intellectual delusions. This was not because he was an incorrigible ‘rationalist’, or a bad scientist who did not like to make observations or devise experiments (both of which he did a lot), but because he was aware that in trying to understand the world of physics and ourselves, we need to be warned against making our everyday experience of ordinary things intrude into the explanations of things natural. If we would keep judging knowledge on the basis of our common sense experience of objects and events, we would never achieve any scientific progress, but would remain stuck with classical types of philosophical description, in particular the Aristotelian categorisation of things.

Descartes accordingly does not fit into the rigid Kantian dichotomy between rationalism and empiricism — but then again, no one does. The real Descartes was in fact concerned with criticising arm-chair types of philosophising. He only doubted the reliability of the senses because he knew that in our efforts to try and understand the world as well as ourselves in scientific ways, we should leave behind our common-sense conceptions of things, as well as the way in which we think and speak about them on the basis of our everyday experience.

Descartes knew it had traditionally been the great mistake of philosophy to make our common experience the leading factor in the description of nature. As a result, pre-Cartesian philosophy had never arrived at any insight in the fields of physics, chemistry or biology, but had remained stuck in classical, especially Aristotelian, descriptions of reality. If we would continue only to have an eye for individual ‘things’, their ‘inner substance’ and their ‘outer properties’, it was highly unlikely we would ever get beyond the kind of subject-predicate descriptions of the world by which we link qualities to substances and attribute to the objects of everyday experience a metaphysical essence. Classical thought had made us spin around in philosophical circles and prevented natural philosophy from explaining anything worthwhile about the processes that elude our common sense world-outlook.

Descartes also knew that the problem ran deep. Throughout his life, he insisted that we are epistemically biased by our childhood and by the distorted image we have of reality on the basis of our language use. In an effort to find a method that went beyond the common-sense interpretation of things, he showed science the way: reality was no longer to be divided into individual ‘things’, nor should science any longer be seen as the attempt to attribute causal responsibilities among these separate agents. Of course, we do this all the time in our daily lives, but according to Descartes (who, again, was 350 years ahead of Antonio Damasio in this respect) we do this only because it is useful in order for us to survive. We have an innate cognitive survival mechanism that is functional in that it allows us to recognise things very quickly, but real ‘knowledge’ of these very same things is something else entirely.

Science calls for a method that bypasses our direct sensory experience, but we have a hard time getting rid of the influence of our subjective involvement in nature. Our daily dealings with the world are strongly integrated with our conceptions of the what the world is made of; conceptions that are enshrined in the grammar of our language, in our logic and our philosophy. It was important, according to Descartes, that we reflect on this at least once in our lives, and learn to distinguish our 1st-person experience of the world from the 3rd-person description of what is going on. That profound lesson about our epistemological situation as human beings, first presented in Descartes’ Meditations, is still of utmost importance for understanding both the world we live in and ourselves.

Descartes Today

Descartes’ contribution to physics was short-lived, as his attempt to interpret nature mechanistically was soon to be supplanted by Newton’s far more successful way of limiting oneself as a scientist to a mathematical description of dynamic processes. But although Descartes’ way of doing science soon became obsolete, this did not make his theory of knowledge any less relevant. In fact, Descartes’ philosophical development can be reconstructed as a continuous attempt to learn more about both the world and ourselves from the perspective that reality as we know it presents itself in our daily experience in ways that only very indirectly relate to the processes we try to describe and understand by scientific means – which is a truth in many ways still relevant today.

Descartes devoted an entire philosophical life to the proper demarcation of the subjective and the objective perspectives. Over the next two years, the project Decoding Descartes will continue to try and formulate how present-day paradoxes in philosophy and science link up with what Descartes put on the philosophical agenda almost four centuries ago — not only in order to come to a reinterpretation and reappraisal of the work of the least understood philosopher in the Western tradition, but also in order to offer a new, twenty-first-century, appraisal of its continued relevance.


[1] Barnaby R. Hutchins, Christoffer Basse Eriksen, and Charles T. Wolfe, ‘The Embodied Descartes: Contemporary

Readings of L’Homme’, in: Delphine Antoine-Mahut and Stephen Gaukroger (eds), Descartes’ Treatise on Man and its Reception, Studies in the History and Philosophy of Science 43, Cham: Springer, 2016, pp. 287-304 (quotation from p. 278).

[2] Han van Ruler, ‘Philosopher Defying the Philosophers: Descartes’s Life and Works’, in: Steven Nadler, Tad M. Schmaltz and Delphine Antoine-Mahut (eds), The Oxford Handbook of Descartes and Cartesianism, Chapter 1, Oxford: Oxford University Press, pp. 3-24.

[3] Lilly Alanen, ‘Descartes’s Dualism and the Philosophy of Mind’, Revue de Métaphysique et de Morale 94 (1989-3), pp. 391-413 (quotation from p. 392). Alanen may historically count as the ‘first mover’ in the philosophical revision of our understanding of Descartes, but it should be added that she was heavily inspired by Descartes-scholars in the earlier, twentieth-century French tradition, just as I was myself.

[4] Ian Hacking, ‘The Cartesian Vision Fulfilled: Analogue Bodies and Digital Minds’, Interdisciplinary Science Reviews 30 (2005-2), pp. 153-166 (quotation from p. 159). In his article, Hacking refers to a young American who once put him on the trail of Descartes’ Principia and to the work of Heleen Rozemond as positions that bear some resemblance to what he himself was trying to say vis-à-vis Ryle.

[5] Antonio Damasio, Self Comes to Mind: Constructing the Conscious Brain, London: Vintage Books, 2012, pp. 292-293.

[6] Daniel C. Dennett, Consciousness Explained, Borton: Little Brown, 1991, Preface and Chapter 2: ‘Explaining Consciousness’.

[7] Dennett introduces the example of a tennis player in his discussion of the famous Libet experiment; cf. Daniel C. Dennett, Freedom Evolves, New York: Penguin, 2003, pp. 238-242. Towards the end of the first part of The Passions of the Soul, Descartes likewise introduced the possibility of training oneself for developing reaction patterns that refuse to be come about on the basis of conscious volitions. Cf. Les Passions de l’âme I 46-50, AT XI, pp. 363-370.

[8] Francisco J. Varela, Evan Thompson and Eleanor Rosch, The Embodied Mind: Cognitive Science and Human Experience, Cambridge, Mass: MIT Press, 1993. See for instance pp. 134ff, 65ff and 140ff for the use of the respective swear words.