III. What Can We Know: Descartes and the Meditations on First Philosophy
D. Meditation Five: God and the foundation of knowledge, the ontological argument
Meditation Five covers much of the same ground as Meditation Three. Descartes constructs an argument for the existence of God. Descartes constructs this argument to prove that God exists as a perfect being. A perfect being cannot be a deceiver. Therefore, God cannot be a deceiver. If god is not a deceiver, then that which we know by the natural light, that which we can comprehend clearly and distinctly, must be as we comprehend it to be.
While this new attempt to prove that god exists may seem redundant, the Meditation Five argument for God’s existence plays a somewhat different role in the overall structure of the Meditations than Meditation Three.
1. A glance back at Meditation Four
Meditation Five comes after Meditation Four, which is titled, “Concerning the True and the False.” Although I am not requiring you to read Meditation Four, it does answer an important question that the Meditation Three argument raises. This question is, “Why, if God is no deceiver, are not all my beliefs certain?” In other words, “Why did the perfect God create a being [the cogito, the thinking thing] that is, seemingly, imperfect in its understanding?”
In Meditation Four, Descartes argues that we are not imperfect in our understanding. We make mistakes in our judgements, not in our understanding. This is because, in addition to giving us the rational capacity to discern what ideas are clear and distinct, God also gives us the freedom to judge as we will. Thus, we can, and often do, make a judgement about what is true when we do not have a vivid and distinct idea of what we are passing judgement on. This, according to Descartes, is the source of error in judgement. In exercising our god given freedom of will, we pass judgement on ideas that are not vivid and distinct.
Descartes does acknowledge that God could have chosen to create him so as to never make false judgement. However, Descartes then states that while he might be more perfect than he is he had been created so as never to make false judgments, there “may somehow be a greater perfection in the universe as a whole that some of it parts are not immune to error, while others are, than if all of them were exactly alike.” In other words, we as individuals have less perfection than we might have so that the universe as a whole might be more perfect.
Descartes then councils us to follow the following rule: “abstain from making judgements whenever the truth of a given matter is not apparent.” If we follow this rule, we can be free of the error hasty judgement leads us to.
Because Descartes repeatedly invokes the notion of that which is “vivid and distinct” this designation is worthy of some remark. First, recall Bennett’s note on his translation at the start of Meditation 3. While he translates Descartes’ Latin and French as “vivid and clear” most other translation use “clear and distinct.” For our purposes these two phrases are interchangeable. Second, there is the question of the relation of our ability to discern what is clear and distinct in accordance with Descartes’ understanding of what he calls the “natural light.” In his reply to an objection made by the English philosopher Thomas Hobbes in the “Objections and Replies” that were published with the Meditations, Descartes writes “As everyone knows, a ‘light in the intellect’ means transparent clarity of cognition.” (Replies 3)[1] This seems to make the natural light the same as the notion of clarity and, perhaps, distinctness. However, in his Meditations, Descartes never defines what it means for a concept to be clear and distinct. Elsewhere, in his Principles of Philosophy, Descartes writes, “I call a perception “clear” when it is present and accessible to the attentive mind … I call a perception “distinct” if, as well as being clear, it is so sharply separated from all other perceptions that it contains within itself only what is clear.” (Prin. 1:45)[2]
In this and other passages, Descartes seems to be saying that a perception (and Descartes uses “perception” in a way closer to our notion of idea than our notion of a perception) is clear if we can comprehend precisely what the perception is and distinct if we can clearly separate it from all other perceptions. For Descartes, if there is no deceiver, whatever we perceive clearly and distinctly must be as we perceive it to be.
Thirdly, many philosophical commentators on Descartes have claimed that there is fundamental flaw in his reasoning. Throughout both Meditation 3 and 5 Descartes uses the fact that he perceives something by “the natural light” [of reason] as justification for its truth. He does this prior to proving that he is not being deceived and as a means of demonstrating that he is not being deceived. However, might Descartes not be deceived about the illumination given by the natural light? Is he justified in using it to reason that God exists and is no deceiver if, indeed, he is so deceived? This criticism of Descartes, is now called the Cartesian Circle. It was first noted by his contemporary Marin Marsenne in his “Second Set Of Objections” to Descartes’ Meditations.
2. Meditation Five
With Meditation Four in the background, in Meditation Five Descartes initially turns to his thoughts about things that seem to exist outside of him. This, interestingly, turns Descartes to thinking about triangles. This is because, unlike the objects of our senses, we can have clear and distinct knowledge of the essential properties of triangles. Geometry shows us that triangles are completely knowable through reason alone. Based on this Descartes then asks whether this can also lead him to a proof of god’s existence. His first thought is, “yes, this must be so because existence is part of the essence of god in the same way that three-sidedness is part of the essence of a triangle.” Descartes initially questions whether this must be so. However, he then states, “Just as it is self-contradictory to think of highlands in a world where there are no lowlands, so it is self-contradictory to think of God as not existing—that is, to think of a supremely perfect being as lacking a perfection, namely the perfection of existence.”[3]
Descartes then discusses why this is not immediately evident to everyone. Descartes responds to this by stating, “if my thoughts were not hemmed in and pushed around by images of things perceived by the senses, I would acknowledge God sooner and more easily than anything else.”[4] Thus, with this as with other ideas, Descartes argues that the problem is with our tendency to not make the concerted effort to think clearly and distinctly about the question of god’s nature and existence.
Descartes’ argument in Meditation Five for the existence of God is a version of what is called an “ontological argument.” Ontic refers to being. (Ontology is the branch of metaphysics investigating what must be for there to be anything at all.) Ontological arguments for the existence of god are arguments that rest on the concept of god as opposed to any kind of evidence there may be for God’s existence. In this way, they are essentially different from cosmological arguments for god’s existence. Ontological arguments have a long history in philosophy of religion. In this history, the version of the ontological argument presented by a philosopher-theologian Bishop Anselm of Canterbury (1033/4–1109) is most prominent.
Here is a Crash Course Philosophy video on Anselm’s version of the ontological argument.
As the Crash Course video indicates, Anselm’s argument has been widely criticized. After you have read Meditation 5, ask yourself whether the same objections that apply to Anslem’s version of the ontological argument apply to Descartes’ version.
Descartes provides us with both cosmological and ontological arguments for God’s existence. For Descartes, these arguments are not just about whether god exists. They are also about whether we can have knowledge that goes beyond the very limited knowledge of the cogito. For Descartes, this depends on there being no demon deceiver.
“Thus, I see plainly that the certainty and truth of all knowledge depends strictly on my awareness of the true God. So much so that until I became aware of him I couldn’t perfectly know anything. Now I can achieve full and certain knowledge of countless matters, both concerning God himself and other things whose nature is intellectual, and also concerning the whole of the corporeal nature that is the subject-matter of pure mathematics.”
Read “Meditation Five”
(For this Meditation, try to read it through and follow Descartes’ argument. If you do not understand a part of it, make a note of it, this is something that can be brought up in and worked out in class.)
3. Fifth Meditation: The essence of material things, and the existence of God considered a second time
There are many enquiries still to be made about God’s attributes, and many about my own nature (that is, the nature of my mind). I may take these up at some time; but right now I have a more pressing task. Now that I have seen how to reach the truth—what to do and what to avoid—I must try to escape from the doubts that beset me a few days ago, and see whether anything can be known for certain about material objects.
Before enquiring into whether there are any such things, I should consider the ideas of them in my thought, in order to see which of those ideas are distinct and which confused.
I distinctly imagine quantity—that is, the length, breadth and depth of the quantity, or rather of the thing that is quantified. I also enumerate the thing’s parts, to which I attribute various sizes, shapes, positions and movements; and to the movements I attribute various durations, ·that is, I say how long each movement lasts·.
Size, shape, position and so on are well known and transparent to me as general kinds of phenomenon, but there are also countless particular facts involving them that I perceive when I attend to them. The truths about all these matters are so open to me, and so much in harmony with my nature, that when I first discover any of them it feels less like •learning something new than like •remembering something I had known before, or •noticing for the first time something that was already in my mind without my having turned my mental gaze onto it.
The most important point is that I find in myself countless ideas of things that can’t be called nothing, even if they don’t exist anywhere outside me. For although I am free to think of these ideas or not, as I choose, I didn’t invent them: they have their own true and immutable natures, ·which are not under my control·. Even if there are not and never were any triangles outside my thought, still, when I imagine a triangle ·I am constrained in how I do this, because· there is a determinate nature or essence or form of triangle that is eternal, unchanging, and independent of my mind. Consider the things that I can prove about the triangle—that its three angles equal two right angles, that its longest side is opposite its greatest angle, and so on. I now clearly recognize these properties of the triangle, whether I want to or not, even if I didn’t give them a thought when the triangle first came into my mind. So they can’t have been invented by me.
It does not help to point out that I have sometimes seen triangular bodies, so that the idea of the triangle might have come to me from them through my sense organs. I can prove truths about the properties not only of triangles but of countless other shapes that I know I have never encountered through the senses. These properties must be something, not pure nothing: whatever is true is something; and these properties are true because I am clearly aware of them. (I have already proved that everything of which I am clearly aware is true; and even if I hadn’t proved it, my mind is so constituted that I have to assent to these ·geometrical· propositions as long as I perceive them.) I remember, too, that even back in the times when the objects of the senses held my attention, I regarded the clearly apprehended propositions of pure mathematics—including arithmetic and geometry—as the most certain of all.
·The preceding two paragraphs lead to this conclusion·: The mere fact that I find in my thought an idea of something x, and vividly and clearly perceive x to have a certain property, it follows that x really does have that property. Can I not turn this to account in a second argument to prove the existence of God? The idea of God (that is, of a supremely perfect being) is certainly one that I find within me, just as I find the ideas of shapes and numbers; and I understand ·from this idea· that it belongs to God’s nature that he always exists. This understanding is just as vivid and clear as what is involved in ·mathematical· proofs of the properties of shapes and numbers. So even if I have sometimes gone wrong in my meditations in these past days, I ought still to regard the existence of God as being at least as certain as I have taken the truths of mathematics to be.
At first sight, this looks like a trick. Where things other than God are involved, I have been accustomed to distinguish a thing’s existence from its essence. ·The question ‘What is the essence of triangles (or flames or sparrows)?’ asks what it takes for something to qualify as a triangle (or flame or sparrow). Answering this still leaves open the existence question, which asks whether there are any triangles (or flames or sparrows)·. I can easily believe that in the case of God, also, existence can be separated from essence, ·letting us answer the •essence question about God while leaving the • existence question open·, so that God can be thought of as not existing. But on more careful reflection it becomes quite evident that, just as having-internal-angles-equal-to-180° can’t be separated from the idea ·or essence· of a triangle, and as the idea of highlands can’t be separated from the idea of lowlands, so existence can’t be separated from the essence of God. Just as it is self-contradictory to think of highlands in a world where there are no lowlands, so it is self-contradictory to think of God as not existing—that is, to think of a supremely perfect being as lacking a perfection, namely the perfection of existence.
[What Descartes wrote is usually translated as ‘mountains in a world where there are no valleys’, but that is obviously not self-contradictory. The Latin provides no escape from this, but Descartes may have been thinking in French, in which vallée can mean ‘valley’ in our sense but can be used to refer to foothills, the lower slopes of a mountain, or the plain immediately surrounding the mountain. So ‘highlands’/‘lowlands’ has been adopted as a compromise: compact and fairly close to what he presumably meant.]
·Here is a possible objection to the preceding two paragraphs·:
I can’t think of God except as existing, just as I can’t think of a river without banks. From the latter fact, though, it certainly doesn’t follow that there are any rivers in the world; so why should it follow from the former fact that God exists? How things are in reality is not settled by my thought; and just as I can imagine a winged horse even though no horse has wings, so I can attach existence to God in my thought even if no God exists.
This involves false reasoning. From the fact that I can’t think of a river without banks, it does not follow that a river with banks exists anywhere, but simply that river and banks— whether or not there are any in reality—are inseparable. On the other hand, from the fact that I can’t think of God except as existing it follows that God and existence are inseparable, which is to say that God really exists. My thought doesn’t make it so; it doesn’t create necessities. The influence runs the opposite way: the necessity of the thing constrains how I can think, depriving me of the freedom to think of God without existence (that is, a supremely perfect being without a supreme perfection), like my freedom to imagine a horse with or without wings.
Here is a ·further· possible objection to this line of thought:
Admittedly, once I have supposed that •all perfections belong to God, I must suppose that he exists, because existence is one of the perfections. But what entitles me to suppose God to have all perfections? Similarly, if I suppose that •all quadrilaterals can be inscribed in a circle, I have to conclude that a rhombus can be inscribed in a circle; but that is plainly false, which shows that the original supposition was wrong.
I agree that I don’t have to think about God at all; but whenever I do choose to think of him, bringing the idea of the first and supreme being out of my mind’s store, I must attribute all perfections to him, even if I don’t attend to them individually straight away. This necessity ·in my thought· guarantees that, when I later realize that existence is a perfection, I am right to conclude then that the first and supreme being exists. Similarly, I don’t ever have to imagine a triangle; but whenever I do wish to consider a figure with straight sides and three angles, I must attribute to it proper- ties from which it follows that its three angles equal no more than 180°, even if I don’t notice this at the time. When on the other hand I examine what figures can be inscribed in a circle, I am not compelled to think that this class includes all quadrilaterals. Indeed, I cannot—while thinking vividly and clearly—even pretend that all quadrilaterals can be inscribed in a circle. This kind of false pretence is vastly different from the true ideas that are innate in me, of which the first and chief is the idea of God. This idea isn’t a fiction, a creature of my thought, but rather an image of a true and unchanging nature; and I have several indications that this is so. •God is the only thing I can think of whose existence necessarily belongs to its essence. •I can’t make sense of there being two or more Gods of this kind; and after supposing that one God exists, I plainly see that it is necessary that he has existed from eternity and will stay in existence for eternity. • I perceive many other attributes of God, none of which I can remove or alter.
Whatever method of proof I use, though, I am always brought back to the fact that nothing completely convinces me except what I vividly and clearly perceive. Some things that I vividly and clearly perceive are obvious to everyone; others can be learned only through more careful investigation, but once they are discovered they are judged to be just as certain as the obvious ones. (Compare these two truths about right-angled triangles: ‘The square on the hypotenuse equals the sum of the squares on the other two sides’ and ‘The hypotenuse is opposite the largest angle’. The former is less obvious than the latter; but once one has seen it, one believes it just as strongly.) ·Truths about God are not in the immediately obvious class, but they ought to be·. If I were not swamped by preconceived opinions, and if my thoughts were not hemmed in and pushed around by images of things perceived by the senses, I would acknowledge God sooner and more easily than anything else. The supreme being exists; God, the only being whose essence includes existence, exists; what is more self-evident than that?
Although I came to see this only through careful thought, I am now just as certain of it as I am of anything at all. Not only that, but I see that all other certainties depend on this one, so that without it I can’t know anything for sure. ·The next two paragraphs explain why this is so·.
While I am perceiving something vividly and clearly, I can’t help believing it to be true. That is a fact about my nature. Here is another: I can’t fix my mind’s eye continually on the same thing, so as to keep perceiving it clearly; so that sometimes the arguments that led me to a certain conclusion slip out of my focus of attention, though I remember the conclusion itself. That threatens me with the following state of affairs, from which I am protected only by being aware of the existence of God:
In a case where I am not attending to the arguments that led me to a conclusion, my confidence in the conclusion might be undermined by arguments going the other way. When I think hard about triangles, for instance, it seems quite obvious to me—steeped as I am in the principles of geometry—that a triangle’s three angles are equal to 180°; and while I am attend-ing to the proof of this I can’t help believing it. But as soon as I turn my mind’s eye away from the proof, then in spite of still remembering that I perceived it very clearly ·but without now getting it clear in my mind again·, I can easily doubt its truth. So nothing is ever finally established and settled—I can have no true and certain knowledge, but only shifting and changeable opinions. For I can convince myself that I am naturally liable to go wrong sometimes in matters that I think I perceive as evidently as can be. This seems even more likely when I remember that I have often regarded as certainly true some propositions that other arguments have later led me to think false.
That is what my situation would be if I were not aware of the existence of God.
But now I have seen that God exists and have understood that everything else depends on him and that he is not a deceiver; from which I have inferred that everything that I vividly and clearly perceive must be true. So even when I am no longer attending to the arguments that led me to accept this (·i.e. the proposition about triangles·), as long as I remember that I vividly and clearly perceived it no counter-arguments can make me doubt it. It is something that I know for certain ·and in an unshakable way· to be true. That applies not only to this one proposition but to anything that I remember ever having proved in geometry and the like. Why should I call these matters into doubt? •Because I am so built as to be prone to frequent error? No: I now know that when I have something in mind in a transparently clear way I cannot be in error about it. •Because I have in the past regarded as certainly true many things that I afterwards recognized to be false? No: the things that I later came to doubt had not been vividly and clearly perceived in the first place: I had come to accept them for reasons that I later found to be unreliable, because I hadn’t yet discovered this rule for establishing the truth. •Because I may be dreaming, so that my present thoughts have as little truth as those of a person who is asleep? I put this objection to myself a while ago. It doesn’t change anything, because if something is evident to my intellect, even when I am dreaming, then it is true.
Thus I see plainly that the certainty and truth of all knowledge depends strictly on my awareness of the true God. So much so that until I became aware of him I couldn’t perfectly know anything. Now I can achieve full and certain knowledge of countless matters, both concerning God himself and other things whose nature is intellectual, and also concerning the whole of the corporeal nature that is the subject-matter of pure mathematics.
Exercises
1. Now, having read Meditation 5:
a. What are Descartes’ key conclusions?
b. What reasons does he give for these conclusions? (In other words, summarize his arguments.)
c. Is his version of the Ontological Argument subject to the same criticisms as is Anselms?
d. Do you accept his claim that he has argued beyond the possibility of doubt that God exists and is no deceiver? Explain why you have the view you do.
2. Do you have any questions or additional comments?
- Descartes, Rene, Meditations on First Philosophy, in the version presented at www.earlymoderntexts.com ↵
- The Philosophical Writings of Descartes, Cottingham, John, and Robert Stoothoff, and Dugald Murdoch. (eds.) 1984. Cambridge: Cambridge University Press. 1:207f ↵
- Descartes, Rene, Meditations on First Philosophy, in the version presented at www.earlymoderntexts.com ↵
- Ibid ↵