Clear and Distinct Perception of the External World: Descartes Meditations Five and Six
The Firestone Files: Letters to My Grandchildren — Dr. Chris L. Firestone
December 22, 2025 · Episode 18 · 24:08
https://drchrisfirestone.com/episode/clear-and-distinct-perception-of-the-external-world-descartes-meditations-five-and-six/

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Greetings and welcome everyone. I'm Dr. Chris L. Firestone and this is the Firestone Files. Over the past few months, we've been on quite a journey together, meeting the Fire Stones and celebrating the life of Charlie Kirk. And now, as we enter December, we embark on something new, a special series I'm calling Decart December. All through this month, borrowing any festive detour, we will turn our attention to one of the most significant figures in western thought, Renee Deart. Across five episodes, I'll guide you on an intellectual journey through Renee Deart's famous meditations on first philosophy. These lectures include an introduction, meditations 1 and 2, meditations 3 and 4, meditations 5 and six, and a conclusion.

So, I invite you to grab a notebook and a copy of the meditations if you have one, your favorite mug filled with your favorite drink, and settle in with me through December as we walk with Daycart through doubt, discovery, and deep reflection. This is Decart December. I am Dr. Chris L. Firestone, and this is the Firestone Files. Enjoy.

Hi, I'm Dr. Chris Firestone, professor of philosophy, and this is the fourth in a series of lectures on the philosophy of Renee Deart. Today we're going to look at his last two chapters, meditations five and six of his famous meditations on first philosophy. So far in the course, we've had an introductory lecture where we laid out some of the background of the of the book and of Decart's life and how it led to this monumental shift from metaphysics's first philosophy to epistemology as first philosophy in the dawn of the modern age or what's sometimes called the age of reason. As we moved into the meditations themselves, I suggested that these meditations acted like six days of creation.

uh do in the cannon of scripture. Meditations uh 1-6 act as kind of uh six days of creation for the philosophical cannon where by the time we get to meditations six which we're going to talk about today, Decart has uh uh argued for a composite mindbody um uh nature of the human person. And so that's that's what we're going to have to look forward to today. He started in meditation one with his method of doubt with the singular goal of trying to achieve certainty.

uh that meditation that that meditation assumed the existence of an evil demon and like virtually every religious uh tradition origin story and religious traditions from Buddhism to uh uh Islam to Christianity there is present an evil demon and uh Decart assumes this evil demon not as a real person but as a thought experiment that would help him to make certain that his judgments regarding what he could be certain of would in fact be true. And so he left in meditation one with that uh famous quotation about his assumption that he has no eyes and ears and uh arms or anything else because he could be fooled of these evil demon uh could fool him.

And we talked a little bit about um the movie Inception in the Matrix and how they they uh you know life could be a dream and how do we know we're not dreaming and so forth. When we get to meditation 2, we established the quest for the Archimedian reference point for all knowledge. That is what point of knowledge can we be so certain of that we couldn't doubt even in the face of a malignant and all powerful evil demon. And Decard has this eureka moment that it is I think I'm a mental substance. I can't be fooled of this for in order to fool me, I'd have to be somebody capable of being fooled. I'd have to be a mental substance.

It's a circular argument to say that you could fool me into this truth. And he famously develops this idea that isn't really found in meditation too, but it's sort of uh present there. I think therefore I am uh I am as often as I think it. And even if I try to imagine a migant demon fool me fooling me of this, it would not be possible. I'd still have to be a thinking thing.

when he goes into meditation three he wakes up in the morning says Eureka I am a thinking thing I found that Archimedian reference point but he notices an issue almost immediately and that is I'm a thinking thing that has ideas and these ideas have a certain quality and quantity about them that cannot be explained just by the blank mind as it were that my finitude my my my lack of predication and so forth are inabil that don't have the ability to explain or the quality and quantity of ideas that I actually have interacting with my mind. Many of which are not intentional. You know, things come into our purview that we didn't call in, you know, like one might do with their imagination. They just happen to us. There is something out there. We're not alone.

Now, what could constitute an idea in the mind of a thinking thing? Well, first of all, it have to be another mental substance, and it'd have to be a cause sufficient to the effect. And so, that mental substance would have to be both infinite and perfect in order to constitute the ideas that I actually do have in my mind. No other finite mind can explain the quality and quantity of ideas that I have. And he of course calls this God. And so, we have this whiteboard, God. the ends realism, the infinite well of predication that is God's nature. And then we have the existence of myself as a conscious being uh being appeared to by an interaction uh that can only be explained by God.

Now we move to meditation four and we ask the question Deart asks the question am I moving too quickly? Are my inferences you know I had one small step for man I made one giant leap for mankind to the existence of God. Am I moving too quickly? Can I trust my judgment? And Deart basically suggests that the intellect in and of itself is not fallen. It's not prone to error. It's when it's wedded to the will. And when our wills get lazy or we're not being critical or they're not disciplined and they they seem to just accept things willy-nilly that things can go astray.

So Decart famously at the end of meditation 4 suggests that if I have a disciplined judgment then reason is the measure of truth and the age of reason is dawned. And I argue that that sentence towards the end of meditation 4 is the very centerpiece of the western philosophical tradition and we're still trying to come to grips with it even today. Now as we move into meditation five, Decard is after more. He doesn't really uh just want the self or God, but he definitely wants to get to the existence of the external world.

This is the moment he's been waiting for throughout his philosophy because remember it was the gains and the and and insights of science and mathematics that forced him down this road in the first place because the great strides that they'd been making. Metaphysics and the old ways of doing philosophy weren't measuring up to the pragmatic utility of mathematics and indeed the truth of math and science as they were beginning to emerge. And so the whole point of the meditations is to ground science and mathematics on a firm foundation of knowledge, a philosophical basis if you will.

And uh meditation five, he realized he hasn't quite gotten there yet. We have God, we have the self, both as mental substances, but uh one finite, one infinite, but we don't yet have the existence of the external world. How do we get there? Well, the first place that Decart goes is he goes back to God. And this is something I think that's oftentimes missed in lectures that I've had back in college and so forth is just how central God is to the entire argument for the trustworthiness of science and the the very uh uh uh inferential uh u um let's see positivity or or confidence that we have because God is all powerful.

He's all good. We would expect that he would not deceive us and so forth. And he has part of his very nature he's going to suggest and this is an additional point. He's only made a kind of colloquial argument so forth for the existence of God. But in meditation five he talks about the necessary existence of God that I can't even think God without existence being part of his nature. He uh he brings up this famous analogy of the mountain in the valley. He says, "Just as a mountain has a valley, God has existence."

And then he challenges that very notion to say, "Hold on a second. That's a disanalogy." Because just because mountains have valleys doesn't mean they exist. And just because I can think God doesn't necessarily mean that God exists. And so if I look over here at meditation five, uh, we get a little taste of how this argument is going to work. But though in truth I cannot conceive a god unless as existing any more than I can a mountain without a valley. Yet just as it does not follow that there is any mountain in the world merely because I conceive a mountain with a valley. So likewise though I conceive God as existing it does not seem to follow on that account that God exists.

So he's challenging the analogy. Existence doesn't necessarily follow like valleys follow mountains. But the cases are not analogous, he says. And a fallacy lurks under the semblance of this objection. For because I cannot conceive a mountain without a valley, it does not follow that there is any mountain or valley in existence, but simply that the mountain or valley, whether they do or do not exist, are inseparable from each other. Whereas on the other hand, because I cannot conceive God unless as existing, it follows that existence is inseparable from him and therefore that he really exists. Not that this is brought about by my thought or that imposes any necessity on things, but on the contrary, the necessity which lies in the thing itself, that is the necessity of the existence of God.

In other words, buried in the perfection of God is necessary existence. For without this necessary existence is actual existence, he wouldn't in fact be the most perfect being. And this of course is a hearkens back to Anselm and other examples of the argument. But necessary existence is an important attribute to this. Decart doesn't think from meditation three that I can get God in mind except as existing and as a cause sufficient to the effects of the ideas that I have. That kind of existence is a necessary existence for the very light bulb to go on that is consciousness. Without that you don't have the uh uh uh the raw materials that are of the intellect.

You have a blank slate. It requires God to be opposite us and to have necessary existence as part of his being. Now this leads us to consider or leads Deart to consider the nature of the kinds of ideas that he has. If God is infinite and he's perfect and he would not deceive us and he has necessary existence as part of his being and so forth, then what do we make out of clear and distinct perceptions both in mathematics and in immediate sense perception? Well, Dart's pretty clear about this that God would not fool us of something so clear and distinct and that uh among these clearest and and and and distinct um elements has to be those things that are immediately present to us.

And this will be a transition as we make that we make between book five and book six or meditation five meditation six because he's returned to the proof for the existence of God. He's pressed the point that God not only exists but has necessary existence as part of his being. Clear and distinct perceptions he would not fool us of. Things like I'm being appeared to by a camera or this office or uh nature he wouldn't fool me of. Now there are particular ways in which I'm fooled. He uses the example of a a tower that's off in the distance that looks circular but as he gets closer it looks uh train it looks like a a rectangle. and so forth that I can have individual perceptions. But when I am careful, clearly perceiving, not drunk, uh not on drugs, getting enough sleep, disciplined in my judgments, I have no reason to think that they are not trustworthy.

And because God is not a deceiver, the evil demon has been vanquished. I can trust that the external world in fact exists. Now this will lead and we're going to talk about this maybe at the end of this lecture or into the uh concluding lecture to what is sometimes called the cartisian circle and that is Deart seems to be using clear and distinct ideas that lead to the notions of infinity and perfection for example to prove the existence of God then he's using the existence of God to prove the existence of clear and distinct perceptions of the external world and that to some people sounds like a circular argument.

Um, I will just say that there are two types of circular argument and uh I'm not going to land necessarily on which one it is here with Renee Deart, but there's the viciously circular argument where you're actually using um illegitimately using features of one premise to prove another and you use the other to prove the original one and so forth. or there's virtuous circular arguments which have a kind of reciprocity to them that is that one requires of the other. And um I think Decart's response is that this is basically a virtuously circular argument. Um but be this as it may, we have in meditation five the establishment of further establishment of God's nature and God's existence and the trustworthiness of clear and distinct perceptions.

As we uh then make our way over to meditation six, we have him employing it straight away. We look over at meditation six. There now only remains the inquiry as to whether material things exist. With regards to this question, I at least know with certainty that such things may exist in so far as they are constitute the object of pure mathematics since regarding them in this aspect I can conceive them clearly and distinctly.

Deart is going to argue here at the beginning of meditation six that clear and distinct perceptions of the external world though not perfect like mathematical concepts do give rise to those concepts.

uh they help us to intuit they quicken and they awaken uh these concepts within our mind and so forth and because they're clear and distinct these perceptions that we have in the external world and God is not a deceiver they are in fact trustworthy and uh now again one has to be critical one has to be careful if you go all the way back to his early rules for the direction of the mind you still have to interpret your world you still have to withhold judgment until you have careful data and analysis before you make judgments.

But you should have the confidence to do science and to do mathematics because God is not a deceiver and that the apparatus that he's given you, the intellect is capable as it were of apprehending the world clearly and distinctly and the external world is thus trustworthy. So, we hit this property emerging, sometimes called the property of extension, that things seem to stretch out in the space-time continuum.

And that is a clear and distinct perception that I have that must be grounded in the very nature of God. And yet, um, and we get to the existence of the external world because of it. Now the place he goes in meditation six is to the clearest and most distinct uh uh uh experience that we have and that is of our own bodies. I remember when I was uh traveling, I've had a couple trips into the Grand Canyon. Once spent two weeks down through the Grand Canyon, and my tour guide took us to these uh oases that were created by uh the local Indian population many, many years ago.

And on the walls across the canyon where it looked to be impossible for human beings ever to get, you would see handprints on the wall that somebody took some ink and blew the ink right on the wall and you could see their handprint like they were saying, "Look, can you do that?" Uh but one of the things it shows me is the fascination humans have always had for the body and um our hands. The ability to manipulate and to move our hands and our entire bodies to feel pain and pleasure and so forth is an extraordinary thing. And of course they're the most clear and distinct perceptions that we have.

Decart talks about examples of people losing their limbs and still thinking they have feeling in them and so forth and that perhaps we could be fooled of these things. Nevertheless, but uh we have psychological analysis and so forth to help us to understand that things that typically speaking our our bodies as an extension of of our minds. So what he calls extended mental substances are among the most clear and distinct perceptions that we have.

And so if we fast forward it here over to meditation six, he says um but there is nothing which nature teaches me more expressly or more sensibly than that I have a body which is illffected when I feel pain and stands in need of food and drink when I experience sensation of hunger and thirst etc. And therefore I ought not to doubt but that there is some truth to these informations.

And so he goes on to say I have no re I've already shown the mind can exist independently of the body and yet I have a body and it seems to coincide harmoniously with my mind. And this is a clear and distinct perception of which I can be most certain because I am certain that I exist and that God exists and he's not a deceiver and that my judgment is trustworthy and that clear and distinct perceptions are thus trustworthy. And the most clear and distinct perception of all is that I have a body. And so Deart is going to distinguish mental substance from extended mental substances like my body, like objects of nature and so forth.

And there's evening and there's morning on the sixth day. So what has Deart done? He's proving the existence of the self, having a soul and having a body. He's proven the existence of God. He's proven the trustworthiness of nature. He's ex he's proven the existence of the external world. And so the famous three things that must be shown as a foundation for all knowledge, God, the self, and the world are all found here uh in the six meditations um the meditations on first philosophy. So Dart's taken us on quite an odyssey.

He's left us with a couple of problems. one I've already mentioned the cartisian circle uh whether or not it's a vicious or virtuous circle u I'll leave that up to you you can read the meditations for yourself but he's also left us with the mind body problem that we are mental substances and we are extended mental substances and Deart sees that in all the evidence that he has is that there is a smooth and continuous relationship between the mind and the body but how does this relationship work. If we have mental substances and we have physical substances, how do they connect one with another? I think I see two possible solutions in Decart.

One is a principle of some some sort of pre-established harmony that God in God's infinite wisdom has established between the mind and the body. And there's also the famous answer that he gave, I think, in response to um to Hobbes's objections and so forth, that there's a gland in the back of the neck, the pineal gland, that somehow the mind winds up and smacks this gland and uh you know animates the body, per se. Um the pineal gland answer to the mind body problem really hasn't gone anywhere. I don't think that's taken seriously by many philosophers. the pre-established harmony suggestion idea has been taken up uh as a possible answer and there are uh numerous other uh ways in which the mind body problem is handled. All right.

Well, that's it for now. Those are the six meditations. In the next uh final lecture, we'll try to wrap all this up and uh kind of address the question, where do we go from here? Thanks for stopping by to spend some time with me here on the Firestone Files. I hope today's reflections offered you some new insights and perspective on life. If you enjoyed the episode or found it valuable, I'd appreciate it if you'd take a moment to like, subscribe, and share it with someone you care about. I'd also love to hear your thoughts. What resonated with you? What challenged you? Or what would you like to hear more about in future episodes? Drop a comment below or send in your suggestions to the email in the description. Your input helps shape where we go next. This has been Dr. Chris Firestone. Until next time, keep asking the big questions. And remember, the kingdom journey is always best with your friends. Further up and further in. Bye for now.

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