Descartes’ Foundationalism/Literature

 Descartes’ Foundationalism

Chapter Outline 1. Foundationalism 2. Euclid’s Parallel Postulate 3. Descartes’ Method of Doubt 4. The Method Applied to a Posteriori Beliefs 5. Dubitability Is a Logical, Not a Psychological, Property 6. The Method Applied to Beliefs Based on Rational Calculation 7. I Am Thinking, Therefore I Exist 8. Thesis of the Incorrigibility of the Mental 9. Do First-Person Psychological Beliefs Provide a Sufficient Foundation? 10. An Additional Foundational Belief: God Exists and Is no Deceiver 11. How to Prove that God Exists 12. The Clarity and Distinctness Criterion 13. The Cartesian Circle 14. Conclusion

René Descartes (1596–1650) is sometimes described as the father of modern philosophy. The kind of epistemology he tried to develop is called foundationalism. Before launching into the details of Descartes’ philosophy, I want to describe the kind of approach to the problem of knowledge that foundationalism provides.

Foundationalism The word foundationalism should make you think of a building. What keeps a building from falling over? The answer has two parts. First, there is a solid foundation. Second, the rest of the building, which I’ll call the superstructure, is attached securely to that solid foundation. Descartes wanted to show that (many if not all of) the beliefs we have about the world are cases of genuine knowledge. To show this, he wanted to divide our beliefs into two categories. There are the foundational beliefs, which are perfectly solid. Then, there are the superstructural beliefs, which count as knowledge because they rest securely on that solid foundation.

Read Meditations 1–5 of Meditations on First Philosophy on www.mysearchlab.com

Besides this metaphor from architecture, there is another that should help you understand what Descartes’ project is. You probably had a geometry course in high school where you studied Euclid’s development of the subject. Recall that Euclid, who lived about 2,200 years ago, divided the propositions of geometry into two categories. First, there are the axioms of geometry. These are supposed to be simple and totally obvious truths. Second, there are the theorems, which at first glance are somewhat less obvious. Euclid shows that the theorems are true by showing how they can be deduced from the axioms.

A foundationalist theory of knowledge could also be called a Euclidean theory of knowledge. To show that a given body of beliefs counts as knowledge, we use the following strategy: First, we identify the beliefs that will provide the foundations of knowledge (the axioms). These must be shown to have some special property, such as being totally beyond doubt. In a moment, I’ll clarify what Descartes had in mind by this “special property.” Second, we show that the rest of our beliefs count as knowledge because they bear some special relationship to the foundational items. In Euclid’s geometry, the special relationship was deductive implication.

Euclid, of course, was interested only in the beliefs we have about geometry. Descartes had a wider ambition. He was interested in the totality of what we believe. But whether the problem is to describe the foundations of geometry or the foundations of knowledge as a whole, there are two ideas that must be clarified. We need to identify what the foundational items are and we need to describe the relationship that must obtain between foundational and superstructural items that qualifies the latter as knowledge. In doing so, we need to remember that the building metaphor is only a metaphor. What makes the foundation of a house solid is that the walls are thick and hard and are set deeply into solid ground. But foundational beliefs aren’t foundational because they are thick and hard and planted deeply in dirt. What, then, does it mean, for a belief to be “foundational”?

Euclid’s Parallel Postulate If your high school geometry course was like mine, you spent most of your time seeing what theorems could be proved from the axioms. You spent little or no time seeing why the axioms should be regarded as true. You were told that they are “obvious,” or that they should just be accepted on faith. Maybe your teacher said that geometry is just a game and the axioms are the rules. In fact, the question about the axioms is a serious one. One of Euclid’s starting assumptions—his so-called fifth postulate—bothered geometers for about two thousand years. This postulate says that if you have a straight line (call it S) and a point not on that line, then there is exactly one straight line that goes through that point and is parallel to S. In other words, the parallel postulate says that if you extend all the lines passing through this point to infinity, exactly one of them will fail to intersect the initial line.

A number of subsequent geometers felt that this assumption of Euclid’s was less obvious than the other assumptions he used. As a result, they tried to show that it could be proved from the other axioms. Geometers repeatedly failed to do this, and eventually it was established that the parallel postulate cannot be proved from Euclid’s other assumptions. That is, they showed that the parallel postulate is independent of the other assumptions. This means that the denial of the parallel postulate is logically consistent with Euclid’s other assumptions. It then transpired that non-Euclidean geometries could be developed, ones that retain Euclid’s other assumptions but reject his parallel postulate.

The details of this story don’t matter here. The history of geometry does show, however, that it sometimes isn’t so clear whether a given statement is “obviously true.” Perhaps Euclid thought that the parallel postulate was obvious. If so, that would have been his justification for treating it as something that doesn’t need to be proved; it would stand on its own as an axiom/postulate. This doesn’t mean, however, that subsequent geometers had to regard Euclid’s judgment as beyond question. What strikes one person as obvious may not be so obvious to someone else.

Descartes’ Method of Doubt Now let’s consider Descartes’ approach to the problem of knowledge. Descartes’ goal is to refute skepticism. He wants to show that we really do have knowledge of the world we inhabit. His strategy for achieving this goal is foundationalist in character. This means the first item on his agenda is to identify the beliefs that are foundational.

At the beginning of his Meditations on First Philosophy (1641), Descartes proposes a method for determining which of his beliefs are foundational. He called this the method of doubt. For each proposition you believe, you see whether it is possible to doubt that proposition. If it is possible to do this, you set the belief aside—it isn’t foundational. If it isn’t possible to do so (that is, if the belief is indubitable), then the belief is foundational. Notice that failing the method of doubt test doesn’t show that the belief is false. It just means the belief isn’t absolutely certain.

Descartes doesn’t try to apply this method to beliefs one at a time. Think of all the beliefs you have—there are millions (at least). You believe that 1 is a number. You believe that 2 is a number. And so on. It would be time consuming and also boring to try to consider each belief separately. Rather, Descartes considers kindsof beliefs; he considers whether all the beliefs in this or that category pass or fail the method of doubt test.

Indubitability Very few propositions are made true just by your believing them. You can believe that there are unicorns, but that doesn’t make such creatures pop into existence.

Consider the proposition “I am thinking.” If you believe that this is true, then it must be true. Believing is a kind of thinking. Descartes thinks that the same is true for propositions of the form “I seem to see that p.” He also thinks that this is true for propositions that say that you believe that p or want it to be true that q (where p and q are propositions). If you believe them, they must be true. If a proposition is made true by your believing it, then you can’t describe a situation in which you believe the proposition but the proposition is false. Descartes determines whether a proposition is dubitable by seeing whether he can describe a situation of this kind. This means that a proposition is indubitable if the proposition is made true by the act of believing it (or doubting it).

Are there indubitable propositions that aren’t made true by your believing them? Some philosophers have held that simple logical truths, such as “It is raining or it is not raining,” are beyond doubt. Is it plausible to maintain that these are made true by your believing them?

The Method Applied to a Posteriori Beliefs The first category Descartes considers is the set of beliefs that depend for their justification on sense experience. Many of our beliefs are based on sight, hearing, touch, taste, and smell. These propositions are a posteriori; recall this piece of vocabulary from Chapter 8. Is it possible to doubt these beliefs? Descartes says that the answer is yes. Your present belief that there is a printed page in front of you is based on vision. Vision, however, can be misleading. Psychologists tell us about hallucinations and illusions. Maybe you’ve had such experiences yourself. If not, remember Macbeth, who was certain that a dagger was hovering in front of him. Besides hallucinations, there is the fact of dreaming. In a dream you may find yourself believing that there is a printed page in front of you. You may find yourself having visual experiences just like the ones you are having now. But in the dream, your belief is mistaken. Descartes takes this to show that the belief you have right now might be mistaken. So beliefs that rest on the testimony of the senses fail the method of doubt test. Let’s be clear on why Descartes thinks they do so. Descartes shows such beliefs are dubitable by constructing a story of a particular kind. You now believe that there is a printed page in front of you on the basis of a set of visual experiences. Let’s call the proposition you believe B and the experiences you now are having E. Your belief that B is true rests on your having experiences E. Descartes holds that B can be doubted because he can describe a situation in which you have E and believe B and yet B is false. Dreams and hallucinations show how this can happen. Descartes shows that a class of beliefs is dubitable by constructing a story of this sort.

Dubitability Is a Logical, Not a Psychological, Property In saying that a belief is dubitable, Descartes isn’t saying that we are able to take seriously the idea that it might be false. The proposition that there is a page in front of you is dubitable in Descartes’ sense; this doesn’t mean that you are now about to take seriously the possibility that no page is present. A proposition is dubitable when a certain sort of story can be constructed; dubitability is thus a logical property that a proposition has. It has nothing to do with whether we can get ourselves to believe that the proposition might be false.

The Method Applied to Beliefs Based on Rational Calculation Descartes next turns his attention to propositions of mathematics. I believe that 2 + 3 = 5. I believe that squares have four sides. Descartes remarks that these are true “whether I’m awake or asleep.” These propositions are a priori (recall this piece of vocabulary from Chapter 8). They don’t depend for their justification on sensory experience. Do propositions justified by reason, independent of sense experience, pass the method of doubt test? Descartes thinks they fail. To demonstrate that such beliefs are dubitable, Descartes asks us to imagine that our minds are deceived by an “evil demon.” Imagine that an evil demon causes our faculty of reasoning to find propositions totally obvious that in fact are false. If this were so, we might believe that 2 + 3 = 5 even though the proposition isn’t true. These conclusions—all reached in the first of the Meditations—are entirely negative. A posteriori beliefs about the character of the world outside the mind are dubitable. We see this by considering dreams and hallucinations. A priori propositions also are dubitable. We see this by considering the evil demon. If no belief in these two categories passes the method of doubt test, which beliefs could be the foundations of knowledge? What category of belief could possibly satisfy this very stringent requirement?

I Am Thinking, Therefore I Exist In an earlier work, the Discourse on the Method (1637), Descartes identifies a pair of propositions that pass the test:

I noticed that while I was trying to think everything false, it must be that I, who was thinking this, was

something. And observing that this truth, I am thinking, therefore I exist [Je pense, donc je suis in

French; Cogito ergo sum in Latin], was so solid and secure that the most extravagant suppositions of the

skeptics could not overthrow it, I judged that I need not scruple to accept it as the first principle of the

philosophy I was seeking.

In the Second Meditation, Descartes focuses on the belief “I am, I exist” as the first proposition that he thinks is beyond doubt.

To understand what Descartes is driving at, you must think about yourself, formulating your thoughts in the first person. When Descartes considers the proposition “I am thinking,” you aren’t supposed to consider the proposition “Descartes is thinking.” Rather, you should say to yourself precisely what Descartes says to himself.

Consider my belief that I am thinking. I can’t doubt this. It is impossible for me to construct a story in which I believe this proposition, though it is false. For if I believe the proposition, then I am thinking, and so the proposition is true. So the attempt to doubt the proposition fails; the attempt to doubt the proposition proves that the proposition must be true. The proposition “I am thinking” passes the method of doubt test.

There are two important characteristics of the proposition “I am thinking” that you should note. First, it is important that the proposition is in the first person. When Descartes considers “I am thinking,” he concludes that this proposition passes the method of doubt test. However, if he had considered “Descartes is thinking,” the result would have been different. It is possible for Descartes to doubt that there is someone named “Descartes.” He can invent a story in which there is no such person as Descartes; the fact that such a story can be constructed shows that the proposition is dubitable. The second feature of the proposition “I am thinking” is that it involves a psychological property. I can’t doubt that I am thinking, but I can doubt that I am now in North America. Both beliefs are first-person, but only the former is psychological.

As noted, Descartes maintains that the proposition “I exist” also passes the method of doubt test. Take a few minutes to formulate an argument, similar to the one just described for “I am thinking,” that shows that this is so.

So far, we have two propositions that Descartes thinks can serve as foundations for the rest of what we know. I can’t doubt that I am thinking and I can’t doubt that I exist. This is a meager foundation. Just as it would be hard to erect a big building on a foundation made of two bricks, so it would be difficult to ground the whole of what we know about the world on this paltry foundation of two beliefs.

There is more, however. Consider propositions solely about the contents of your own present sensory experiences. Such propositions describe the way things seem to be, not the way they in fact are. You now seem to see a page in front of you. Descartes thinks that all such first-person descriptions of the way things seem are indubitable. To understand Descartes’ point, it is essential to recognize the difference between the following two propositions:

• There is a page in front of me. • I seem to see a page in front of me. It is pretty clear, as noted earlier, that the first of these can be doubted. That’s the point about dreams and illusions. Descartes maintains that the second proposition is different. He holds that it has the property that if you believe that the proposition is true, then you can’t be mistaken. If you believe that you seem to see a page in front of you, then you do seem to see a page in front of you. You can’t be mistaken in your beliefs about the way things seem.

So the foundation of knowledge has just been augmented. “I am thinking” and “I exist” are indubitable, and so are the many first-person beliefs about the way things seem.

Thesis of the Incorrigibility of the Mental Descartes went even further. He thought that people have infallible access to what they believe and desire. Introspection (“looking inward”) is a method that the mind can use to accurately grasp its own contents. This is sometimes expressed by saying that Descartes believed in the thesis of the incorrigibility of the mental.Although “There is a page in front of me” isn’t indubitable, Descartes thought “I believe that there is a page in front of me” is indubitable. If you believe that you have that belief, then it must be true that you do have that belief. Ditto for desires. If you believe that you want some ice cream, then it must be true that you want some ice cream.

A great deal of work in psychology in the last hundred years shows that this incorrigibility thesis isn’t plausible. Sigmund Freud, whose views on religion came up in Chapter 10, argued that we often misunderstand what we really believe and what we really want. At times, our beliefs and desires would be very upsetting to us if we were conscious of them. So, as a defense mechanism, our minds repress them. The result is that we often have mistaken beliefs about what we really think and want. An example of this is Freud’s theory of the Oedipus complex. Freud held that little boys want to kill their fathers and marry their mothers. If you asked a little boy whether he wanted to do this, however, he probably would sincerely answer no. You might well ask: What evidence can there be for this theory? If little boys deny having these desires, why think they have them? Freud’s answer is that his theory is a plausible explanation of what little boys do. It is their behavior that we must

consider, not just what they say they believe and desire. Verbal reports about what we think and want are evidence as to what our beliefs and desires really are. Sincere reports, however, don’t settle the matter, since behavior may provide other evidence that is relevant. Although this idea—that we often have a false picture of our own beliefs and desires—is very important in Freud’s theories, it isn’t unique to them. A great deal of other work in psychology also denies Descartes’ thesis of incorrigibility. See, for example, the 1977 article by R. Nisbett and T. Wilson called “Telling More Than We Can Know” (Psychological Review 84: 231–59). Descartes wants to include all first-person reports of his own beliefs and desires as foundations. Each, he thought, passes the method of doubt test. Freud and many other psychologists would disagree. I’m on their side.

Where does this leave Descartes’ project of identifying the foundations of knowledge? The foundations include I am thinking and I exist and all first-person reports about the way the world seems to be. Another example of an indubitable belief might be “I am in pain.” Descartes’ view was that if you believe that you are in pain, then you are in pain.

In Chapter 2, I pointed out that for a very large class of our beliefs, there is a huge difference between believing a proposition and that proposition’s actually being true. To believe that the Rockies are over ten thousand feet is one thing; for the mountains to actually be that high is another. It is misguided wishful thinking to hold that believing the proposition guarantees that it is true. This sensible separation of belief and truth, which seems right for a wide class of propositions, is called into question by the special examples that Descartes thought pass the method of doubt test. According to Descartes, “I am in pain” must be true if I think it is. The same holds for “I am thinking” and “I seem to see a page in front of me.” These are cases in which wishful thinking seems to work.

Do First-Person Psychological Beliefs Provide a Sufficient Foundation? These propositions, Descartes thought, are foundational. We can’t be mistaken in believing them. Some philosophers have disagreed with Descartes’ claim. They have maintained that it is possible to be mistaken in holding some of these beliefs. I’m not going to address that matter here. Instead, I want to consider another problem. Recall the architectural metaphor discussed at the beginning of this chapter. An adequate foundation for a building must have two properties. It must be (1) secure and (2) sufficient to support the superstructure. The foundations of knowledge are subject to the same requirements. According to Descartes, they must be indubitable. In addition, it must be possible to rest everything else we know

on them. Don’t forget that the method of doubt is intended to identify the foundations; the entire superstructure is supposed to rest on that basis.

Descartes, as I mentioned before, wasn’t a skeptic. He thought that we know lots of things about the world outside our own minds. For example, you know that there is a page in front of you now. This belief about the external world isn’t indubitable; it didn’t pass the method of doubt test. Nevertheless, it is (Descartes would agree) something you know. How can Descartes show that this is true? Recall the Euclidean analogy. We’ve just identified some axioms of the system of knowledge. Do these suffice to prove some theorems? We must show how you know there is a page in front of you by showing how this proposition is connected with foundational ones. In Euclidean geometry, we justify theorems by deducing them from axioms. How can a superstructural belief be shown to be knowledge? We must show that it is connected with foundational pieces of knowledge in the right way. But what is this special connection supposed to be?

Can deduction do the trick? Euclid deduced theorems from axioms. Can Descartes deduce propositions about the world outside the mind from beliefs that are first-person psychological reports? To show that you know that there is a page in front of you, maybe we should try to deduce that proposition in the following way:

• I seem to see a page in front of me.

•

• There is a page in front of me.

The premise of this argument is foundational. The problem is that it does not deductively imply the conclusion. The existence of a page in front of me does not deductively follow from the way things seem to me now. That’s the point noted before about dreams and hallucinations. The above argument is not deductively valid.

The premise given isn’t enough. Even if I augmented it with other reports about my present psychological state (for example, “I seem to feel a page,” “I seem to taste a page,” etc.), that still would not be enough. Such premises might be ones about which I’m perfectly certain, but they don’t provide a sufficient foundation for the beliefs I have about the world outside my mind. Such arguments are not deductively valid.

An Additional Foundational Belief: God Exists and Is No Deceiver Descartes saw quite clearly that the argument just described needs an additional premise, one that will bridge the gap between first-person psychological premises and a conclusion

that describes the world outside the mind. Descartes thought the proposition that God exists and is no deceiver provides the additional premise that he needs.

How would this additional premise solve Descartes’ problem? Descartes had the following picture in mind: God created your mind and situated you in the world. What sort of mind did God give you? Obviously, he didn’t give you a mind that reaches true conclusions about the world on each and every occasion. Your mind isn’t infallible. On the other hand, God would not have furnished you with a mind that leads you to false beliefs about the world no matter how carefully you reason and no matter how much evidence you consult. If God had done this, he would have been a deceiver. Descartes thinks that God created us with minds that have the capacity to attain true beliefs about the world. We are neither infallible nor hopelessly trapped by falsehood. Rather, we are somewhere in between: We can reach true beliefs if we are careful about how we use the minds that God bestowed upon us. This is the kind of mind that an all-PKG god would have given us. But why think that such a being exists?

How to Prove that God Exists I’ve just explained what role the proposition that God exists and is no deceiver is supposed to play in Descartes’ theory of knowledge. However, if this proposition is to be a part of the foundations, it must be indubitable. It must pass the method of doubt test. Descartes has to show that the proposition that God exists and is no deceiver is not just true, but that it is indubitable. Here Descartes seems to be trying to do the impossible. Isn’t it obvious that it is possible to doubt that God exists and is no deceiver? After all, atheists or agnostics don’t believe that God exists. Isn’t this enough to show that it is possible to doubt that God exists and is no deceiver?

Descartes thinks that atheists and agnostics have not considered the matter carefully enough. They think they can doubt the proposition, but they have not really grasped what this would really involve. (Recall Anselm’s comment about the “fool” who “said in his heart what cannot be conceived.”) Descartes believes that he has a proof of the existence of God whose premises are indubitable. In addition, the proof is so simple that once you attend carefully to it, you can’t doubt that there is a god. This is the proof that Descartes lays out in the Third Meditation. Here it is, in outline:

1. My idea of God is an idea of a perfect being. 2. There must be at least as much perfection in the cause as there is in the effect.

o

o Hence, the cause of my idea is a perfect being—namely, God himself.

Once you inspect this proof, the proposition that God exists is like the proposition I am thinking—it is impossible to doubt that it is true.

Descartes thinks he knows premise (1) of this argument by introspection. By looking inward at the contents of his own mind, he can discern this fact about himself. Premise (1), Descartes believes, is indubitable. As to premise (2), Descartes thinks that it is an indubitable principle about causality. It can be broken into two components. First, there is the idea that every event has a cause. Second, there is the idea that the cause must be at least as perfect as the effect. It isn’t clear why we should accept these principles about causality. For example, why couldn’t some events occur for no reason at all? This is a question we explored in Chapters 4 and 7. Descartes needs to show not only that it is true that every event has a cause, but that this proposition is indubitably true. This is something that he does not succeed in doing. Premise (2) needs to be clarified. Descartes distinguishes two kinds of perfection (or “reality”) that an idea or representation might possess. To find out how objectively perfect a representation is, you must find out how perfect the thing is that the representation represents. Two photographs of a saint must have the same degree of objective perfection; two photographs of a trash can will have the same degree of objective perfection as well. If saints are more perfect than trash cans, the first pair will have more objective perfection than the second.

This characterization of objective perfection requires a little fine-tuning. A picture of a unicorn has a certain degree of objective perfection, even though there are no unicorns. So, to determine how objectively perfect the picture is, you must ask yourself this question: If the picture represented something that actually existed, how perfect would that thing be?

I hope you can see from the definition of objective perfection why Descartes thinks that his concept of God has the maximum amount of objective perfection. This is something that Descartes can say just by examining his concept of God. Indeed, it is something that an atheist might agree to as well. If there were a God, then that being would have all the perfections; this means that the atheist’s concept of God is objectively perfect.

The concept of objective perfection allows some representations to be ranked higher than others. My idea of God is at the top. Somewhere below that is my idea of a saint. And still further down the list is my idea of a trash can. The second kind of perfection that Descartes discusses is different. This is what Descartes calls an idea’s formal perfection. All mental contents have the same degree of formal perfection because they are all made of the same stuff. To see what Descartes has in mind here, consider paintings. These may differ in their degree of objective perfection, but all are made of canvas and paint. In this sense, they have the same degree of formal perfection. Descartes thinks the same holds for all the ideas I may have.

In the argument for the existence of God that I just sketched, Descartes is talking about the objective perfection of his idea of God. Let’s reformulate the argument to make this explicit:

1. My idea of God is objectively perfect.

2. If an idea is objectively perfect, then the cause of that idea must be a perfect being. Hence, God exists.

Premise (2) strikes me as implausible. Here is a way to see that it is false. I claim that people could form their concept of God (a perfect being) in the following way. They could look at imperfect things in the world and thereby form the idea of limited intelligence, limited goodness, and limited power. Then, by applying the concept of negation (the concept we express by the word “not”) to these ideas, they would obtain the idea of a being who has unlimited intelligence, goodness, and power. This seems to be an entirely possible causal explanation for why we have the idea of a perfect being. If it is possible, then (2) is false.

In the Third Meditation, Descartes explicitly considers this suggestion. He rejects the idea that we might have acquired the concept of perfection by seeing imperfect things and then applying the concept of negation. You should consider Descartes’ argument and decide whether you think it works. Descartes thinks that the only possible explanation for the fact that we have an idea of a perfect being is that a perfect being actually exists and caused us to have this idea. Leaving this exercise to you, I’ll conclude that Descartes’ causal argument for the existence of God is defective. Descartes wanted to show that “God exists” isn’t just true, but indubitably true. This proposition was to be a foundational element in the structure of our knowledge. The argument he gave falls short of this ambitious goal.

The Clarity and Distinctness Criterion If God is no deceiver, how can we tell whether the beliefs we have are true? Descartes thought that if we inspect them carefully, and make sure that they are clear and distinct, we can be certain that they are correct. Descartes maintained that clear and distinct beliefs must be true. If you reason carefully and use your mental faculties in the way that God intended them to be used, you will obtain knowledge of the world you inhabit. Descartes thinks you have an indubitable grasp of the contents of your own mind; he also thinks that you can know indubitably that God exists and is no deceiver. This foundation, he believes, provides a sufficient and secure basis for you to gain knowledge of the world you inhabit.

The Cartesian Circle Philosophers argue over whether Descartes’ argument for the existence of God has a defect that goes beyond the fact that some of his premises are dubious. They have suggested that the argument is circular, given its place in Descartes’ larger philosophical program.

Recall that Descartes wants to prove that God exists and is no deceiver in order to be able to conclude that clear and distinct ideas must be true.

Descartes’ argument for the existence of God, like all arguments, involves the use of reason. For us to recognize that the argument establishes the existence of God, we must use the faculty of reasoning we possess. Descartes’ argument begins by examining his concept of God and determining that this is the idea of a perfect being. Descartes therefore seems to be using the clarity and distinctness criterion in arguing that God exists. Descartes vehemently denied that he was guilty of circular reasoning. This problem has come to be known as the Problem of the Cartesian Circle.

Here’s how I see this issue: Descartes is using the method of doubt test to assemble foundations for knowledge. His goal is to assemble enough premises by this procedure so that he can show that we have knowledge of the world outside our minds. The existence of a God who is no deceiver is supposed to be one of these indubitable premises. Descartes thought his causal argument for the existence of God is beyond doubt; he thought that if you reason your way through the argument, you must find it irresistible.

Why should we agree that the proposition that every event has a cause is beyond doubt? Descartes’ view seems to be that when we consider the proposition carefully, using the full resources of clarification and logic that we possess, we will be driven to conclude that the proposition must be true. This seems to mean that we are applying the clarity and distinctness criterion. If so, Descartes is reasoning in a circle.

Conclusion Where does this leave the project of refuting skepticism? Descartes thought that first- person psychological beliefs are indubitable. He recognized that this, by itself, isn’t enough to show that we have genuine knowledge of the world outside the mind. Additional premises are needed. The following example argument shows how Descartes wanted to bridge the gap between the indubitable knowledge we have of our own minds and the beliefs we have about the world outside our minds:

1. I now believe that the object in front of me is a page. 2. My present belief is clear and distinct. 3. Clear and distinct ideas are true.

There is a page in front of me.

The argument is valid. If the premises are true, the conclusion also must be true. Descartes’ foundationalism can be understood as a pair of claims about this argument. First, he claims that the premises of this argument are indubitable. Second, he thinks that the conclusion of the argument is a proposition we knowbecause it follows from these indubitable premises.

I’ve already discussed premise (1). What of the next two premises? There is a tension between these two claims.

Suppose we grant Descartes that premise (3) is right—that a clear and distinct idea can’t fail to be true. If we grant this, then it isn’t so obvious that my present belief about what is in front of me really is clear and distinct. I may think that it is, but this appearance may be deceiving. So if (3) is right, (2) can’t be beyond doubt. Alternatively, suppose we are able to tell, by introspection, whether a belief is clear and distinct. That will be enough to underwrite the truth of (2). In that case, there is no longer any absolute assurance that (3) is right. The problem here concerns whether we should see “clarity and distinctness” as a purely subjective characteristic of a belief. If I can tell just by examining the contents of my own beliefs whether they are “clear and distinct,” I see no reason to say that a clear and distinct belief must be true. On the other hand, if we treat “clarity and distinctness” as a characteristic that is necessarily connected with truth, I don’t see how I can tell whether a belief is “clear and distinct” just by introspection.

Descartes tried to refute the following skeptical argument, which I described at the end of the previous chapter:

• Knowledge requires the impossibility of error.

• It is now possible that I am mistaken in believing that there is a page in front of me.

•

• Hence, I don’t know that there is a page in front of me.

Descartes accepted the first premise but denied the second. Descartes concedes that we often make mistakes. The senses sometimes play tricks on us, and so does our faculty of reasoning. But the fact that this sometimes happens doesn’t show that it is happening now. If I am reasoning now in a careful and logically rigorous way, then I can’t now be mistaken in what I believe, or so Descartes maintained. So Descartes’ reply to the skeptic’s argument can be put like this:

• If God exists and is no deceiver and I now have a clear and distinct belief that there is a page in front of me, then I can’t be mistaken in thinking that there is a page in front of me.

• God exists and is no deceiver and I now have a clear and distinct belief that there is a page in front of me.

•

• I can’t be mistaken in thinking that there is a page in front of me.

The problem is that Descartes’ argument for the second premise of this last argument wasn’t successful. He wasn’t able to prove that we are embedded in the world in the special

way described by the hypothesis that God exists and is no deceiver. Consequently, he wasn’t able to refute the skeptic’s argument.

Review Questions 1. What is foundationalism in epistemology? What does it have to do with Euclidean

geometry? With building a house? 2. What is the method of doubt test? What does Descartes use this method to do? What

fails the test? What passes? 3. What does it mean to say that there is a “gap” between our first-person

psychological beliefs and the beliefs we have about the world outside the mind? 4. Descartes thought that proving that God exists would help show why we are able to

have knowledge of the world around us. Why did he think this? Is the proposition that “God exists and is no deceiver” foundational, according to Descartes?

5. Analyze Descartes’ causal argument for the existence of God. Suppose that one of Aquinas’s arguments for the existence of God is valid and has true premises. Could Descartes have used it, instead of his causal argument, to prove that God exists?

6. What is the Problem of the Cartesian Circle? 7. In the previous chapter, an argument for skepticism was presented. How would

Descartes evaluate this argument?

Problems for Further Thought 1. Which of the following propositions pass the method of doubt test? How are they

different from each other? ▪ I saw Joe run. ▪ I seem to remember seeing Joe run. ▪ I remember seeming to see Joe run.

2. Can someone mistakenly believe that he or she seems to see a coffee cup? Can someone mistakenly believe that he or she is in pain?

3. I suggested that our idea of a perfect being might be obtained by observing imperfect things and then using the concept of negation. Descartes considers this suggestion in the Third Meditation and rejects it (consult the paragraph that begins “Nor should I imagine that I do not perceive . . . ”). What reason does Descartes give for rejecting this explanation? Are his reasons plausible?

4. In his book The Principles of Philosophy (1644), Descartes defines clarity and distinctness as follows:

I term that “clear” which is present and apparent to an attentive mind, in the same way that we

see objects clearly when, being present to the regarding eye, they operate upon it with sufficient

strength. But the “distinct” is that which is so precise and different from all other objects that it

contains within itself nothing but what is not clear. . . . Perceptions may be clear without being

distinct, but cannot be distinct without also being clear.

Given this definition, can a clear and distinct idea be false?