470. Gary Hatfield on Descartes' Meditations

We're joined in this episode by a leading expert on one of the most famous works of philosophy ever written: Descartes' Meditations.

• G. Hatfield, “Reason, Nature, and God in Descartes”, in S. Voss (ed.), Essays on the Philosophy and Science of Rene Descartes (New York: 1993), 259–87.

• G. Hatfield, Descartes and the Meditations (London: 2003).
• G. Hatfield, “Descartes’ Naturalism about the Mental,” in S. Gaukroger et al. (eds), Descartes’ Natural Philosophy (London: 2000), 630–58.
• G. Hatfield, “Cartesian Circle,” in S. Gaukroger (ed.), Blackwell Guide to Descartes’ Meditations (Oxford: 2006), 122–41.
• G. Hatfield, “The Passions of the Soul and Descartes’s Machine Psychology”, Studies in History and Philosophy of Science 38 (2007), 1–35.
• G. Hatfield,  “Animals,” in J. Carriero and J. Broughton (eds), Companion to Descartes (Oxford: 2008), 404–25.
• G. Hatfield, “Descartes on Sensory Representation, Objective Reality, and Material Falsity”, in K. Detlefsen (ed.), Descartes’ Meditations: A Critical Guide (Cambridge: 2013), 127–50.

• G. Hatfield, Descartes' Meditations (London: 2014).

• G. Hatfield, “Natural Geometry in Descartes and Kepler,” Res Philosophica 92 (2015), 117–48. 

• G. Hatfield, “Descartes: New Thoughts on the Senses,” British Journal for the History of Philosophy 25 (2017), 443–64. 

• G. Hatfield, “L'attention chez Descartes: aspect mental et aspect physiologique,” Les Etudes philosophiques 120 (2017), 7–25. 
• G. Hatfield, “Mind and Psychology in Descartes,” in S. Nadler et al. (eds), The Oxford Handbook of Descartes and Cartesianism (Oxford: 2019), 106–123. 
• G. Hatfield, “Descartes,” in M. Moriarty and J. Jennings (eds), The Cambridge History of French Thought (Cambridge: 2019), 124–134. 
• G. Hatfield, “Descartes's Corporeal Idea of Distance: Information Processing or Mechanical Correlation?” in D. Kambouchner et al. (eds), The Cartesian Brain: Philosophical and Scientific Perspectives (London: 2025) 66–96. 

Full list of Prof. Hatfield’s publications

Note: this transcription was produced by automatic voice recognition software. It has been corrected by hand, but may still contain errors. We are very grateful to Tim Wittenborg for his production of the automated transcripts and for the efforts of a team of volunteer listeners who corrected the texts.

Peter:
Thank you so much for coming on. It's an honor to have a very accomplished expert on the Meditations to talk to us about this famous text. Let's start by talking about just how it fits into his body of work more generally. When and why did he write the Meditations? 

Gary:
Okay, good. One way to approach this kind of question is to think about Descartes' own intellectual development, but also to think about that intellectual development within the context that he was writing. So Descartes began earnest work around 1620, and during the 1620s, he discovered the sine law of refraction and he solved the Pappus locus problem and sort of invented analytic geometry. Now, I say this because I think in understanding Descartes, we have to realize that he was a mathematician and a scientist before he was a physician. So even during that same 1620s, he wrote the beginnings of this work called The Rules for the Direction of the Mind, which was a methodological work and talked about methodology in mathematics and in optics and other areas of natural philosophy, but didn't have a really worked-out metaphysics and didn't have a notion of a universal physics that was a coherent approach to the entire natural world. Now, that changed in 1629, 1630. So he abandoned that work, The Rules, and then he began a first draft, I believe, of the Meditations around that time. And he also produced two other works that are pieces of universal physics: The Treatise on Light and The Treatise on Man. And these works he called his physics. And those he wrote out, he didn't publish them in his lifetime because he was afraid after Galileo was condemned because in The Treatise on Light, he talked about the revolution of the Earth around the Sun. They were preserved and published after his death. We don't have the early draft of the Meditations, but these works were in the following relation. The two works he described as his physics — said, "These are my physics" — and they were meant to stand alone. And then he began to promise that he had metaphysical foundations for this physics. So he began to promise another work: his metaphysics. Well, it took the entire ten years until 1640 for him to complete the Meditations and publish them. And then he advertised them only in his correspondence as being the promised foundations for metaphysics. If you look at the published Meditations, it's the main point of this work. Descartes tells you it's to prove the existence of God and the immortality of the soul. Well, that's not really true. And he wrote to Mersenne at the same time that this work contains all the foundations of his physics. But don't tell anybody because I want them to read this work and become convinced that my physics is the right one before they realize that it refutes the physics of Aristotle. So there he is with a kind of clandestine role for the Meditations to play. It is the promised metaphysical justification. And he had published some intervening works, the Discourse on Method, which gives some hint of his physics or some samples of his physics and talks a little bit about the Meditations, but really doesn't present the primary arguments that are supposed to establish the Meditations and establish the foundations of physics through the Meditations. 

Peter:
And that supposed purpose of the Meditations, to prove the existence of God and the immortality of the soul, is also highlighted in the preface he writes to the Sorbonne, right? 

Gary:
That's right. The letter to the faculty of theology. I think the letters to Mersenne have to take a little precedence here because he's talking freely. It's not that he didn't care about the proof for the existence of God — he needs it for his argument. He doesn't really cover the immortality of the soul except in a little bit of writing, maybe in the preface or the synopsis. So that really turns into the separation of mind from body. But the separation of mind from body is also part of his physics. And the mind itself is still a natural being. We tend to say, well, when he stops talking about matter or stuff to my mind, he's doing something that's not physics. But in his view, I think he thought that the mind is a natural being and it has properties and so on and so forth. 

Peter:
All right. If you bear with me, I'd like to elaborate a little on the notion of Descartes seeing the scholastic Aristotelians as his primary philosophical opponents. I think this motivates a lot of what he does in Meditations, and it'll help us if we have this background. 

Gary:
So there were three tenets of scholastic Aristotelianism at which Descartes especially took aim. The resemblance theory of sensory qualities, which says that there's something in the object that's like the color red that we experience in the mind — that what's in the object resembles what's in the mind. The theory of substantial forms, which was the idea that each kind of thing in nature has a substantial form that's an active principle which forms that thing and makes it be what it is to be that thing. And also an epistemology — an epistemology that always begins from sensory images and which thinks that there's no thought without an image. And within this epistemology, the essences of things might be abstracted by the intellect, but they would be extracted from a set of images. And Descartes wants to turn away this particular conception of what the intellect is really doing. So Descartes counters these views with a no resemblance theory of sensory qualities — such as color, sounds, and odors — and a theory that the kinds of things in nature are not differentiated by substantial forms, but through their corpuscular structure. Magnets don't have an active principle that attracts iron to them — a kind of attractive force, as Aristotelians believe — but their properties are explained through particles having only size, shapes, and motions. His theory of magnetism is clever, but there's not time here to go into the details. The important thing to keep in mind is that Descartes claimed to explain all natural things as collections of particles having different sizes, shapes, and motions. For example, color qualities depend on the spin of particles of light that enter the eye, affect the nerves, and then the mind. There is nothing in objects that resembles the color as experienced. Finally — and this is a key point — Descartes denied that fundamental knowledge comes through sensory images. He distinguished sense and imagination from a purely intellectual cognitive power that he called the pure intellect. The pure intellect responds to intellectual ideas that have no sensory qualities. Descartes in the Meditations sought to train the reader to use this pure intellect, which had been previously obscured because he thought that most people in their childhood become Aristotelians. This Aristotelian philosophy was a kind of natural path for you to follow in childhood when your use of the intellect and reason is not sharp. 

Peter:
Okay, good. So let's dive into the Meditations. And obviously there's a lot to talk about here. Maybe we could start with the kind of the way it's written. This is written in this kind of first-person narration. And sometimes in the work I've read on the Meditations, people distinguish between the meditator and Descartes, the author. And I haven't really made a big deal about that in the previous episodes, but I was wondering whether you think it's important to make that distinction. 

Gary:
Well, I'm guilty as charged. I do make that distinction in my writings about the Meditations. I think one of the things that people are trying to capture here is that the Meditation is not Descartes as he currently existed when he wrote the Meditation with all of his philosophical beliefs that he had at the time. And it's not really a biographical Descartes. It doesn't really purport to recount exact events that happened at some point in the past. Now, the Discourse is biographical, people think. But others think of the Meditations that it's not really biographical. So think of this thing that he does in the First Meditation, and he says, "Well, up until now, I thought that all knowledge came through the senses." Well, Descartes, as he's writing this, doesn't believe that all knowledge comes through the senses, right? He also says, "Well, God might be a deceiver." Well, Descartes, when he's writing the Meditations, doesn't believe that God is a deceiver. He thinks by the end of the Meditation, he'll prove that God's not a deceiver. And these various snippets — a lot of them common sense or Aristotelian tenets — are necessarily reflecting the order at which he considered these points, even if he did kind of go through this sequence in order to get to the final conclusions. So I think another way to understand this comparison of the "I" — not to Descartes himself, but to a fictional character called the meditator — is to think of the Meditations in terms of its literary structure and relate it to the form of the spiritual exercise. A lot of the elements of the spiritual exercise in the text of the Meditations as Descartes wrote it — and this includes the division into six days. In the preface, he has a request that only people should read this who are willing to take time off and meditate along with him in a careful way. He says in the Second Objection, John replies, that he wrote a book of Meditations and not of Theorems or Disputations, because he wanted the reader to carefully attend the things that went along. Now in Descartes' day, there were various forms of spiritual exercise. The two important forms for me are Aristotelian and Augustinian. So Aristotelian is the South, the Augustinian was a more Platonist metaphysics and epistemology. So in the Aristotelian spiritual exercise, you might purge the senses in order to get away from temptation or something like this, but you were still contemplating images when you did your meditative practice. So you might think about the Christ in the Stations of the Cross or something like that. Augustine had a completely different conception of the relationship between the image part of this thing, the intellectual part. He thought you should turn away from images, try to not pay any attention to images at all, and that there was this intellectual faculty which he calls the fleshless eye, which is the tool by which you're to seek God in this Augustinian meditation. So I think Descartes would have recognized that the Augustinian mode is the one that's appropriate for him. And he would write the Meditations as moving away from the senses into the Third Meditation, where there are no sensory images that are used in the proof of the existence of God. And now you're in purely intellectual territory. This continues into the Fourth and Fifth Meditations. The ontological argument — that fits under this scheme as a purely intellectual exercise — so that we can use this literary form to sort of understand why we want to have the "I" separate from Descartes. We want to have the "I" be the meditator, and we want the reader to take on the role of the meditator. 

Peter:
That's really great. That actually reminds me of some of the stuff we covered when we were talking about Spanish mysticism and Ignatius of Loyola, Teresa of Ávila, who are also engaging in spiritual exercises. And there's a debate in that literature also about whether or not to use visual imagery. And I think I even said something when talking about the early Jesuits — oh, this kind of anticipates Descartes in a way. So it's great to see that circle kind of coming closed. I mean, it is important to add in that, of course, Descartes is using this structure of the spiritual exercise for cognitive exercises, not for religious aims, but for metaphysical aim. 

Gary:
Right. He's sort of transposing it, as it were. 

Peter:
You mentioned just now that one of the first things that happens, or really the first thing that happens, is that the meditator induces these doubts. Some of the things that are doubted, apparently, include such obvious truths as "two plus three equals five." But there's other contexts in which Descartes says that when you're confronted with a truth like that, you cannot help but accept it. So what are we to think here? Is it really possible, according to him, that something like the evil demon hypothesis would allow us genuinely to doubt that two plus three equals five? 

Gary:
Yeah. So I think it has a kind of dialectic of doubt here. So in the First Meditation, he brings up the deceiving God hypothesis and says, "Well, if I was made by a deceiving God, it could be then that I go wrong even in doing arithmetic." Then at the beginning of the Third Meditation, he says, "Look, I can't give this up. Two plus three is five. When trying to contemplate it, I can't help but assent." Now the difference is that he thinks that when we doubt it, we're thinking about it indirectly. We're not directly contemplating "two" and "plus" and "three" and "equals." If we do that, we're going to say that two plus three equals five, and we're certain of it. And we say, "Oh, I was doing a little figures the other day." If somebody's doing some figures, and there's been an evil deceiver that's given them a defective mind, then they could actually go wrong when they do their figures. So it's this direct and indirect engagement with the content of the arithmetic example that allows him to say in the one case, while you're tentatively considering it, get down. But then you could doubt things of its class — or even doubt it itself — if you're not paying close attention to the addition itself. So hope that helps. 

Peter:
Yeah, that does help. Maybe we're going to come back to that kind of issue when we get to the Cartesian circle, which we will shortly. But before we can do that, we need to tackle the cogito — "I think, therefore I am" — which he doesn't exactly say in the Meditations, famously, but the argument— 

Gary:
Well, the objection never applies. 

Peter:
Yeah, right. He does say it. He just doesn't say it in the Meditations, right? This is one thing that he thinks he cannot doubt: he cannot doubt that he exists. And there's a lot to say about this. It's hard to know where to start. But maybe you could focus on just what you think is the primary philosophical use to which the cogito is being put here in the Meditations? 

Gary:
Yeah. So the cogito, of course, is maybe the most famous little sentence — certainly of Descartes, but maybe in all philosophy, right? "I think, therefore I am." A lot of jokes about it. Do we really need to prove that we exist to ourselves? So and so forth. Many commentators actually find the cogito to be deservedly singled out, because they think that it's the most important principle that's established in the Meditations, and that it also gives the basis for the real distinction between matter and mind, between the thinking substance and material substance, and that this distinction is drawn right there in the Second Meditation through the exploration of the "I" of the cogito that goes on. Because cogito is right at the beginning of the Meditation — what you're doing and all the rest while you're exploring the "I," right? And that prepares the way for the later real distinction. But Descartes himself says you can't make the real distinction in the Second Meditation, because it might unbeknownst to us be that mind really is matter. And so what we know is that our knowledge that we have now of mind is separate from knowledge that we have now of body, but we don't have knowledge of any connection there might be between those, and we won't get it until we've established that clear and distinct perception is true and we've gone on a little bit more about what it is to perceive a substance. So the real role of the cogito in my view — or the most important role in my view — is that it provides for the extraction of the truth rule. And in the first paragraphs of the Third Meditation, there's this review — and these reviews are common in spiritual exercises, cognitive exercises. There's this review of what's been done in the Second Meditation, and there's a: "Well, we have a piece of knowledge. Piece of knowledge is absolutely certain. What gave it this absolute certainty?" So now we investigate right there what gave it. It says, "Well, only that it was clearly and distinctly perceived — that from my thinking we can get 'I am,'" right? And so if clear and distinct perception is the only basis for the cogito — that's what he claims, so others would say, well, there's other kinds of basis — but he's saying this is it right here. Then it must be that it's infallible, because you can't get absolute certainty from a principle that sometimes is mistaken. So the cogito plays the role of an instance of knowledge that can then be dissected to see what makes it an instance of knowledge, and particularly an instance of what seems to be absolutely certain. And of course, it goes on right away to challenge the truth rule — and even might be thought to challenge the cogito in this indirect way — in the subsequent paragraphs of the Third Meditation. This is all in the service of getting to find out whether there is a God and whether God can be a deceiver. 

Peter:
Just to double check — by truth rule, you mean that whatever is clearly and distinctly perceived is true? 

Gary:
That's right, yeah. 

Peter:
Okay. And he's going to use that apparently to prove God's existence as well, right? 

Gary:
Yes. 

Peter:
I think a lot of people reading along through the Meditations, they find the skeptical part pretty compelling, they find the cogito pretty compelling, and then they get to these proofs of God's existence that they find uncompelling. I'm not sure that's a word, but they don't find it compelling. Do you think that the whole project of the work ultimately falls down because his proofs for God's existence are rather weak? 

Gary:
I do think that the proofs for God's existence fail. I think they're less weak than they've been made out to be. Does the whole project of finding the essences of mind and matter thereby fail? I'm not really sure. Maybe not. It might be that there's a lesser degree of certainty, but still things to come away from the Meditations with. I want to return to the arguments themselves and elaborate on this idea that they're not in as bad a shape as one might usually believe. Sometimes the failure of these arguments is ascribed to the fact that Descartes brings in a metaphysical apparatus that he derives from his enemies, the scholastic Aristotelians. So these are technical terms found in the Third Meditation largely, like the notion of objective reality — which I won't bother to define — or the principle that there's no effect without a cause and the like. And so we could ask: by what right can he appeal to these universal principles in the Third Meditation as part of his alleged proof of God's existence and benevolence? Well, what he says is that he knows these things by the natural light. Now you're going to say, how did that help us? Because surely the natural light is nothing other than clear and distinct perception under another name. And I think that's probably right. On the other hand, he's now in the Third Meditation. He's investigating arguments for the existence of God. And he's already said that questioning things that are known with clear and distinct perception is hypothetical and metaphysical. Maybe not hypothetical, but it's a metaphysical doubt — that is, a very slight. So maybe provisionally he wants to say that he'll trust the natural light and see where it gets him. I think probably people who want to challenge him with the circle don't like that. And so they say he's cheating to bring in the natural light. Others say, well, maybe he needs to have some principles that he can use just to argue, and so maybe it's irrational to expect him to argue without anything to argue from. I don't think that in the end saves him either. What I say is that he's in a better place than we usually think. I think that the arguments in the Third and Fifth Meditation might well be valid — for the arguments that he gives. I think that they're unsound — some premises are not true. And he relies a lot on these premises. These are the premises that clear and distinct perception is a laser lock on truth, right? Clear and distinct perception — we have these perceptions and we know with absolute certainty, or at least we think we know with absolute certainty, what these clear and distinct perceptions are giving us, right? And we find within ourselves the idea of God as an infinite being. When I say that there's some falsehoods here or some lack of soundness, I don't find within myself the innate idea of God. I don't find within myself this power of clear and distinct perception that gets me right at the essences of things — that allows me to directly apprehend the essences of things. So I think if it were right that we have the clear and distinct perceptions, and it were right that we had the innate idea of God in all the ways that Descartes traps it out in the Third Meditation, then he would have a point. And so he can say, "Well, I haven't studied enough. You haven't gone deeply enough in the Third Meditation." But you can only do that for so long. Then we can go back to him and say, "Look, you're telling us that you have these ideas, but we don't have these ideas — but all human minds should have these ideas. So what's the deal?" Eventually somebody's going to just give up. Both of them will give up and go away, but neither will be convinced by the other. 

Peter:
Yeah, I have to say the answer is supposed to be, "Well, go back and study the Meditations more carefully." I think he would be in a bad position to say that to you of all people. You've definitely read it carefully by now. So that also touches on the Cartesian circle. So the Cartesian circle is supposed to be that we use clear and distinct ideas to prove God's existence. And then we point out that this conception of God means that God is not a deceiver. And then we say, "Well, a God who's not a deceiver wouldn't create me with misleading clear and distinct ideas." Right? So you have clear and distinct ideas being used to prove the existence of non-deceiving God, and the non-deceiving God being used to prove the reliability of clear and distinct ideas. And there have been many attempts to break the circle. I'll actually be talking more about this next time. But since I've got you here, what do you think is the most promising way of avoiding the circle for him? 

Gary:
Well, first I'd like to point out that the circle is not a logical circle. It's a methodological circle. It's not that we have a premise in the conclusion. It's that we use the method of clear and distinct perception to perceive that God exists, and then we use God to validate the method — or leaving aside the God part, we use the method to validate clear and distinct perception, and then we use clear and distinct perception to validate the method. So I think it's sort of a methodological circle. Now, I've written some things on the circle, but I'm not sure that I have a most favorite response. What I have come to see is that how well you think he responds to the circle — because, you know, it was brought to his attention by the objectors, he responded to it right then before the work was published — his responses are found in the published work. It depends on what you think he's trying to establish. So a kind of fairly reasonable interpretation of what Descartes is trying to do in the Meditations is that he's trying to establish some principles of metaphysics with absolute certainty. And he wants to establish them without presupposing anything. So that's what I call the strong validation argument. And the strong validation argument, I think, seems to fit his aims, his goals — but also it's really hard to make out that you could do that, because you run into these problems, the circle, and so forth. 

Gary:
Now some strategies are that you then weaken what you're aiming for — that you're not trying to show positively that we have this truth-detecting power that gets right at the metaphysical principles as they are in themselves, but rather we're just trying to remove any doubts there might be about whether our intellect is, in fact, operating well. And so you consider the various challenges to the intellect, like the deceiving God hypothesis, the defective origins hypothesis — which is the idea that we arise out of nature, so our origins could be defective because nature might not create a perfect being — and so forth. So in this case, we remove the doubt, so there are no doubts left with respect to things having to do with the intellect in the Meditations, but there's been no positive proof that clear and distinct perception is able to get us directly at the truth. So we're just left as the last person standing with the remove-the-doubt strategy. So I think the remove-the-doubt strategy helps with the circle, but then it has problems because it maybe doesn't satisfy Descartes' aims. So maybe we think he should reduce his aims to a more warranted belief kind of thing. That's very un-Cartesian, but he actually does that kind of argument in other contexts. Those are the poles of the positions that I think we should contemplate when we want to think about the circle. I'm not sure I can pick a winner. 

Peter:
Yeah, I'm a little surprised. There's something I thought you were going to say, actually, in light of the distinction you drew earlier between direct and indirect clear and distinct ideas. So I thought what you were going to say is, well, when I'm directly currently thinking about something that's clear and distinct to me, then I can't doubt it. So I don't need God to reassure me of that. But what I might need God to reassure me of is that my previous acts of clear and distinct perception have given me conclusions that I can still use now, even though I'm not thinking about them anymore. Now that I know that God's not a deceiver, I know sort of retroactively that those clear and distinct perceptions were in fact reliable. This is what I'm actually going to be getting into in the next episode, in fact. So I'm surprised you didn't go that way, given you seem to set it up before. 

Gary:
Yeah, so that's another response to the circularity problem, and also very interesting. I don't know about what he's going to think if you try to use this indirect thing for God, because he says what we need God for is: we're not directly contemplating these truths. We'll tend to then allow the objections to come to the fore. And you're saying, well, but we can remember that on another occasion, we found the objections wanting, or we found the conclusion totally acceptable and were distracted by the objections. But I'm not sure just remembering that we once had clear and distinct perception — it's enough to sustain the proof. 

Peter:
Yeah, okay. I think that does sound like a problem. Let's go ahead to the end of the Meditations. Obviously, we could do this all day, but something that people, again, kind of say about the Meditations is, “Oh, at the end of the day, the end of the Meditations, all of Descartes' common-sense beliefs are returned to him,” right? So there really are people out there in the street, and he really is sitting by a fire and all the rest of it. Is that a gross misrepresentation of what's happened? 

Gary:
Well, I think the common-sense beliefs — like that there's a world and that human beings have bodies and so forth — those are reestablished in the Sixth Meditation. And he actually says he never meant to doubt them anyway, because no sane person would doubt that there's a world and that people have bodies. He was just using the doubt for whatever purpose, but it wasn't that. But there's another response. The world that you get back is not the same world that you'd have in the beginning. I think that it's reasonable to say at least one of the personas represented by the meditator is an Aristotelian persona. And through the early Meditations, it's brought up that the meditator right now believes that there's a resemblance between sensations and qualities and object. But by the end of the Sixth Meditation, the meditator no longer believes in that. They've followed along the argument and accepted it. So the world that went away is not the same as the world that came back. The world that came back is common sense, but re-described by Cartesian physics. You'd have to go to some of these conferences they had in France in the ’60s and ’70s — 1660s and ’70s — where they studied Descartes' work. And then you could, as a common-sense person, realize that the world, as we now describe it — the Cartesian world — is different than the world that had been described in school before: the Aristotelian world. 

Peter:
Yeah, you've given up all of these sort of childhood superstitions that have been formalized in the technicalities of scholastic philosophy. And you've been put in a world of dualism and mechanist physics and all the rest of it, right? And you also realize that the senses are good for things like astronomical observations. You have to have the senses to actually do astronomy. And the senses are good for navigating the environment. What you should not do is try to — just without checking with the intellect — use the senses to try to establish metaphysics, which he thinks these Aristotelian teenagers have done. 

Gary:
Yeah, because it'll tell you nonsense like there are colors out in the world. 

Peter:
Exactly. Yeah. Okay, one last question. Everyone thinks of the Meditations as the most important thing Descartes wrote. It's not only the thing that people read by him most, but it's one of the most-read philosophical works of all time. Yet he actually told his correspondent, Elizabeth of Bohemia, later on, not to spend too much time on the sort of metaphysical issues that we've been discussing in this whole conversation. So I'm wondering whether Descartes would think it's a mistake for us to treat the Meditations as his central kind of defining work. 

Gary:
Yeah, that's an interesting question. So this thing that you say he said to Elizabeth — he also said on other occasions. Several people he gave that same advice: “Read the Meditations, but then don't dwell there. Go on to do natural science,” basically. I think that's what he was telling them. And this natural science, which was something that he definitely had a lifelong commitment to — from early work until he died — included things that we would now call physics, chemistry, biology, physiology, and psychology. So it was a comprehensive theory of the natural world. And that's what he was really aiming at. And the role the Meditations plays within that is securing the foundations for the physics. So I think Descartes is telling us: once the Meditations has played its role — and you have to seriously study it for it to play that role — he didn't tell Elizabeth not to read it, and he didn't tell her not to study it seriously, and he praised her for having studied it carefully. So I think what we can say is that the Meditations has its role to play, but if you're going to do extended study, he doesn't want you to do it on the Meditations. He wants you to do it on what comes after the Meditations. And this is how he organizes his Principles of Philosophy, a sort of Cartesian textbook of philosophy published in 1644. The first part is a repeating, in more scholastic form, of the metaphysics taken from the Meditations. And then you go to the fundamental principles, the foundations of physics, in Part Two. And then you go to the world — first the astronomical world, and then the world of minerals and plants, in Parts Three and Four. And there's a little methodological thing on the end. Now, the work itself — I think if we take into account this, for instance, as using the structure of a spiritual exercise for cognitive exercise — I think that's an excellence of the work. That's a strong point of the work. That's a creative use of this genre of writing — the religious exercise — taking the form and putting it into the cognitive exercise of the Meditation. So in that regard, I think that the Meditations is a philosophical gem. It just repays rereading. You see new things in it. So for this podcast, I reread the Meditations last couple days. I found new things in it, even though I've read it many times. So I think that the Meditations is Descartes' crowning achievement in a certain way, but you can't use it as the whole story about his philosophy or about him as a philosopher. So you have to take into account that the Meditations is in the service of the natural philosophy. So once you do that, you'll realize that there's this other side of Descartes. If you just focus on the Meditations — especially since it obscures its relation to the natural philosophy — if you just focus on the Meditations, you'll be missing sort of central parts and the central aim of his philosophy, which is to establish a new science. So Descartes wouldn't be Descartes without taking into account and acknowledging his deep devotion to establishing this new physics or natural philosophy. And Meditation has a role in that, but it doesn't complete the job. Principles goes a long way toward completing the job. There are supposed to be two more parts to it. So there's even more stuff for him to say. He then wrote The Passions of the Soul, which also elaborates a part of what he called natural philosophy. But yeah, Meditations is a great work. It's not the whole Descartes. 

Peter:
Great. Okay. Well, we are not going to dwell on it any longer, at least not in this episode. We will soon be getting actually to his views on ethics and the passions and other aspects of his correspondence with Elizabeth of Bohemia, who we're going to spend quite a bit of time with. But actually next time, we're going to be looking at something you mentioned in passing, which is the objections and replies to the Meditations, which tell us a lot more about it. But you've given us a great platform for doing that.