ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel
  • »
  • Education and Science»
  • Philosophy

Literature and Philosophy: Cartesian Dualism in Rene Descartes' Meditations on First Philosophy

Updated on December 12, 2010

Cartesian Dualism: The Problem of the division between Body and Mind

The history of modern philosophy has been shaped, for the most part, since its infancy by the problems Renee Descartes encountered in his Meditations on First Philosophy and subsequent philosophers’ responses to and attempts to resolve Descartes original dilemmas.  Of course, modern philosophy has become quite more complex than a few questions about a few central issues, but none-the-less, Cartesian Dualism shaped the course of metaphysics from when it was published in 1641 on into the 20th century.  This makes an investigation into the issues resulting from Descartes’ Meditations of supreme value to anyone wanting to understand a little bit about the history of metaphysics in modern philosophy.


To begin, one of the most philosophically significant results of Descartes’ Meditations on First Philosophy is the metaphysical implications of his conclusions about the nature of the human mind and body, and their relationship with one another. Descartes concludes in Meditation Six, based upon two separate arguments, that the mind and the body must not only be distinct substances, but ultimately, completely separate types of substances as well. This Cartesian concept of the division between the body and mind has come to be known as “Cartesian Dualism,” and, in the state the philosophical understanding of this divide was left by Descartes, it creates some hairy problems for modern metaphysics to reconcile. To understand all this, we must carefully examine the logic and presuppositions Descartes employs to reach this conclusion.

The first argument Descartes presents for the division of body and mind is based upon his earlier argument for God. Rather than examining Descartes obvious errors in bias, we will, for the time being, leave his presupposition about God alone in order to look specifically at his logic. Descartes begins his argument by asserting that whatever he perceives “clearly and distinctly” is true because it is guaranteed by his proof of God from earlier in the Meditations. An important aspect of Descartes argument here is that God is not a deceiver, but someone Descartes can trust. The philosophical implication for Cartesian metaphysics is, therefore, if what appears “clearly and distinctly” to Descartes turns out to be false, then his God is no God at all, but rather an evil demon, or, to borrow from Hollywood, the matrix. Descartes, having assured himself that his clear and distinct perceptions are true, i.e. that he is not in the matrix, goes on to say that he has a clear and distinct perception of himself as a “thinking” thing, not an” extended” thing. Descartes also asserts another premise along with this: that he has a clear and distinct idea of a body as an “extended” thing and not a “thinking” thing. Descartes then concludes that because he knows himself to be a thinking thing, and that this thinking thing can certainly exist without a body (again, think of the matrix), and because he knows that a body is an extended, non-thinking thing, that his body and mind must be truly distinct from each other, and that, therefore, without the assurance of a God who justifies his “clear and distinct” impressions as true, Descartes “mind” could certainly exist without a body. This is the crux of Cartesian Dualism, as expressed in Descartes.

Rene Descartes, author of Meditations on First Philosophy.
Rene Descartes, author of Meditations on First Philosophy. | Source

Now, to understand this argument, it becomes necessary to distinguish what Descartes means specifically when he calls a substance “thinking” or “extended”. As in all philosophy, Descartes has specific meanings in mind that are not the same as their popular meanings. A “thinking” substance, as Descartes meant it, is one whose essence is thought. Think this through slowly as the ideas appear overly simple if you don’t consider them long enough to appreciate their gravity. To say a “thinking” substance is one whose essence is thought, is to say it is a substance that can be identified by words like supposes, judges, imagines, feels, senses, and ponders. Can any of these words be used to describe something your body does? No, these words are things that only the mind can do. The brain, is a physical piece of matter, it has wrinkles and electricity in it. These are physical things. Think it through carefully and you will see that “mind” is not the same thing as “brain”. Moving on, a thinking substance, therefore, has no physical manifestation. In contrast, an “extended” substances is just the opposite, it is something that has physical existence. By definition, extended substances are ones that “take up space” or “extend into space”. Descartes saw “clearly and distinctly” that his body extended, but could not think, and that his mind thought, but had no extension. Therefore, he concluded they must be fundamentally different types of substances.

Asides from this argument based upon his “clear and distinct” impressions, Descartes also presents a second argument for his division of body and mind. It is one based upon another difference, as he sees it, between what he defines as “thinking” and “extended” substances. He begins by examining his body, which he finds is, by its very nature as a corporeal, or extended, substance, divisible. That is, his body is a type of substance that can be divided into parts, such as tissues, organs, etc. On the other hand, Descartes considered that the mind, a thinking substance, is utterly indivisible in this way. He illustrates what he means by examining all types of things that take place within the mind: emotions, the imagination, impressions of senses, and abstract ideas. He shows how these things are really just separate modes of thought, but that they cannot be separated from the mind in the way a part of the body, say a hand, could be removed.

Let’s follow his point logically through to make sure we understand exactly what Descartes is getting at. The point is subtle and requires us to be thorough. Let’s consider, it is impossible to remove, say, the mind’s capacity to imagine from the mind and leave a recognizable mind intact. Ask yourself, how would you do this? Whereas removing a hand from a body is a relatively simple process that results in two easily identifiably separate “extended” substances, no such result of identifiably separate “thinking” substances can logically be argued. There is no way to remove a mental facet from the rest of the mind, rather, all these “parts” of the mind are really just separate modes of thinking. From this, Descartes concludes that since the mind is an utterly indivisible thing in the way we consider “extended” substances to be divisible, it must be a different type of substance, and therefore, completely separate from the divisible “extended” substance that makes up the body.

Now, granting Descartes the force of his arguments for the moment, let’s examine what he does to try to reconcile the arising dilemma he has presented himself with: how are these two completely separate and different substances, one that has no space or location, and one that is incapable of thought, able to exchange information at all?  Descartes does spend a little more time trying to reconcile this dilemma in his later writings besides Meditations, but he also briefly responds to it within the text itself.  Furthermore, his later arguments are based upon the preliminary ones he presents within Meditations, so an investigation of his attempts within it should suffice to understand Descartes position on how to reconcile Cartesian Dualism.

Descartes attempts to solve this communication between something that can’t think and something that isn’t even physical by inventing an area of the brain that receives signals from all areas of the body.  Descartes describes the process in a pre-scientific understanding of the central nervous system that is surprisingly accurate given the context: messages are carried from a location in the body to this part of the brain.  Now, exactly how this message is sent determines the exact movement within this section of the brain.  This section of the brain is like a vast storehouse that has mental definitions  for each different movement, and there is only one specific mental definition for each movement.  So, depending on the message received, this part of the brain presents the corresponding mental definition to the mind for consideration.  He uses cases of phantom pains to explain his point: the body, having a mangled message sending system resulting from the injury that the missing limb was lost in, sends a mangled message that ells this storehouse part of the brain to present the mental definition, to the mind, for pain in a part of the body that does not exist anymore.  Since the brain, and its exchange system of movements and definitions, has the best possible mental definitions for each movement, the mental definition that would best fit the movement received is presented to the brain.  In the scenario with the missing limb, the mental definition best associated with the movement received is the one of pain for the limb.  So, even though there is no limb, the mind imagines pain in said limb because it is the most accurate mental definition available to it.  This system of justification is confusing.  I wouldn’t worry too much if you didn’t follow it all, because, this elaborate system doesn’t even address the real question.

A portrait of Rene Descartes from 1596
A portrait of Rene Descartes from 1596 | Source

Order your own copy of Meditations on First Philosophy

The ultimate question about Descartes elaborate explanation is, is it successful?  That is, does it resolve the divide between “extended” and “thinking” substance?  This question is a two part question.  The first question is has Descartes made a convincing argument for the existence of this divide plausible?  The second question, then, would be does his storehouse idea work to reconcile the divide he describes?  To answer the first question as simply as possible, no.  The main problem with his argument for a split between body and mind is its dependence upon Descartes’ proof of god which has been so thoroughly debunked over the past few hundred years that it need not be done again here.  Without God, Descartes’ clear and distinct perceptions do not carry the philosophical force to survive his evil genius hypothesis.  In modern terms, Descartes method to prove he wasn’t in the matrix, failed for the same reason they would within the film, the matrix.  Of course this also means we have to throw everything Descartes says out the window, so let’s forget about the evil genius objection for if we concern ourselves with it, it will arrest all progress.  Let, then, the question we ask become: is there any other reason we, or Descartes, can find for believing his clear and distinct perceptions as true?  Remember, if we cannot, than we need not concern ourselves with this apparent divide because we’ve already proven that there is no reason to take his logic seriously, and, therefore, the consequences of such lines of logic cannot carry any significance for they are fabrications, not insights into reality.

The above question could lead to much more digressions than this one insight might first infer.  Rather than be caught in such digressions, let us, instead, turn our attention to the following question: is there genuinely enough evidence for Descartes to make the claim that he clearly and distinctly perceives his body and mind as separate things?  This puts the emphasis on the issue, and not the philosophical implications within the terms.  To ask the question this way is, in essence,  to question Descartes premise that says he clearly perceives that his body is not a thinking substance.  What is his justification for assuming his body, in some fashion, does not possess the modes of thoughts he recognizes as the substances of his mind?  To ask it another way, doesn’t the fact that he has always naturally assumed there is a very real and very natural connection between the two serve as a more clear and distinct impression?  Turning to the text, Descartes says that since he can clearly perceive of his mind separate from a body, it must be that such a case is possible.  His guarantee for this is, once again, God.  The counter argument would start with a question that asks: what reason do you have, just because you can imagine your mind separate from your body, to believe it is so despite your natural and life-long belief that they are, in fact, connected?  Descartes even argues that the mind’s faculty for imagination is linked to its connection with a body.  This suggests, at the least, that what Descartes claims is so clear and distinct is anything but.

Moving on, the second question of Descartes success pertains, as we mentioned earlier, specifically to his attempt to reconcile the split between the mind and body.  His explanation, if you recall, is that there is a part of the brain that signals the mind with the best possible message when it receives a given movement.  The problem with this explanation is, Descartes hasn’t done anything about the real problem, that his, he hasn’t even addressed how two different substances “bridge the gap”.  There is no explanation for how an “extended” movement directly corresponds to a “thinking” idea.  The gap remains as large and as un-bridged as ever, only now it becomes this question specifically: how is it possible for this part of the brain to have access to any “thinking” substance at all?  What Descartes has done is give a specific way to understand the general metaphysical dilemma of Cartesian Dualism. 

How could Descartes answer this?  Are these “thinking” substance definitions somehow stored in an “extended” place, meaning we have a thinking, extended substance?  Many philosophers say that if this were true, we could “see thoughts”, something we cannot do.  Perhaps Descartes would agree with them.  Or, perhaps, he would argue the mind is able to somehow observe a physical manifestation of this part of the brain and then somehow conjures the correct image from some unconscious part or unknown depository?  This explanation is very problematic, at best, and, once again, makes Cartesian Dualism philosophically attractive.  The point of this article, however, is that Descartes didn’t answer the question of how communication, at all, is possible between two substances.  This apparent inability to resolve the split between the mind and body is the interesting and important ramification for modern metaphysics mentioned earlier in this article.

The fact that Descartes did not successfully bridge the gap meant that every important thinker in metaphysics after him, from Spinoza to Hume to Kant as well as others, would try to resolve Descartes problem.  The fact that these attempts have always met with limited success has inspired far more than just philosophers.  Just a cursory example of the past twenty years of film reveal films like “The Matrix”, “eXistenZ,” and “The 13th Floor” all exploit this central unknown relationship between mind and body that is at the center of the human experience.  The image of Descartes demon has literally chased down modern man in all aspects of his culture.  Hume carried Descartes demon to the extent which Descartes would not: why not skepticism?  Why not doubt everything?  The sting of this question found its way into all aspects of human thought.  Despite Kant’s revolutionary take on this issue, this skepticism has found expression in such things as Dadaism in art, modernism in poetry, and even postmodernism in film.

So, given the fact we can now see just how big of a shadow Descartes’ demon has cast, it becomes fair to ask: what has Descartes’ demon really done to us?  Did it do what he set it loose to do?  No, absolutely not, but, perhaps, it did do one thing: provide us with one truth: that whenever we consider our existence, we cannot be wrong that we exist.  At what cost, we can now ask, does this truth come?  Is the world a better place now that we are smart enough to know that it might not exist?  Does that even matter?  How could it?  And if it couldn’t matter, how could any of the discussion post-Descartes matter either?  If philosophy doesn’t matter, than that impulse inside the human which pushes her to ask these pointless questions is beyond pointless, it is cruel, for it is an imaginary carrot leading her into a philosophical hamster wheel.  This is something that most philosophers, and thinkers, would reject.  They have asked questions and have attempted to bridge the “gap” as if their life depended on it.  So, if any voice from inside that drives us to do is not pointless, this certainly must be one such example.

If it matters to know that we might not exist, some of the real value of that knowledge must come from the fact it can, if we allow it, enable us to step back, not take things as seriously as we used to.  A good example of this attitude is asking the question, what’s wrong with any sort of life that is fulfilling?  Or, what is experience (even if we doubt the nature of its existence) if it is not, at least, worth having?  If we know now that we could all be inside the matrix at this very moment, then what more can be done except to make it your own while continuing to follow that questioning impulse that led you to discover the very existence of that matrix?  And if that impulse, in turns, undermines the layer of reality we now refer to as “the matrix”?  Well maybe, at such a point, we should redefine what it means to be a human.  This is who we are.  This is what we do.  These are the questions we ask.  These are the things that drive us.  There must be value because these questions come from the part of a human that refuses to lie to herself.  And, as long as humans learn to ask questions that come from their desire to know the truth, Descartes’ doubt, and the resulting body/mind “gap” will like remain a fertile ground for both intellectual and popular pursuits.  This also speaks to the lasting value of Descartes Meditations as a document of significance to the history of philosophy as well as Western culture and art even until the 21st century, nearly 400 years after he wrote his brief Meditations on First Philosophy.


    0 of 8192 characters used
    Post Comment

    No comments yet.