Hello, In this lecture we are going to be discussing Cartesian skepticism and say a bit about rationalism. We will be going a bit beyond the readings and not necessarily cover every bit of the readings. It is important to do both the readings and view the lecture. I realize that the primary readings are often very difficult. You might read them and wonder “What the heck is this saying?” and be tempted to give up. It is important that you do not and that you do the readings prior to viewing the lectures. When you do, you will find that the lectures will click for you better and that you are also likely to have more additional insights of your own regarding the readings. Descartes is considered to be one of the earliest modern philosophers. His meditations on first philosophy touch on a large numerous subjects, from metaphysics and issues such as dualism and the existence of God, to epistemology which, you will remember, is the study of the nature of knowledge. That is what we will be primarily concerned with here. As we begin to talk about Descartes, it is first important to have a little foreshadowing. Descartes lived to the mid 17th century and was a major figure championing the epistemological theory known as rationalism. Remember that epistemology is the branch of philosophy that investigates the nature of knowledge. Rationalism is the theory that only reason serves as a source of knowledge, at least within some particular subject matter or domain. In particular it holds that we have innate ideas—that is to say a priori ideas (which we will define later) that can tell us something meaningful about the universe. Your primary reading for this view is Descartes, but Plato also expressed some aspects of this view, such as in his allegory of the cave. His student, Aristotle’s views were more in line with empiricism. Empiricism is a theory that can be contrasted with rationalism. This is the doctrine that knowledge comes from sensory experiences. For this theory we will be reading Locke Empiricism relies on a posteriori ideas (to be defined later) and denies that we have innate ideas or at least that they can tell us facts about the actual universe. Rationalism holds that we have innate ideas—ideas that we do not need to learn from the outside world. The most certain truths under the rationalist view are going to be a priori truths. These are truths that we can know before the uses of the senses, such as of logic and other relations of ideas such as mathematics. Empiricism denies that we have innate ideas or that they tell us about the actual universe. Under the theory of empiricism, knowledge is a posteriori. This is information that comes from the senses and is built upon our senses. Scientific truths derived from studying the world fit into this category. Now, Descartes, had long realized that he had often held false beliefs, but waited until he was much older before entering into these investigations. Descartes waited until he believed he had reached an age where he was not likely to improve his cognitive abilities or base knowledge, before attempting to do so. The idea that we have false beliefs is a realization that we are all familiar with. Any time your opinion about some fact has changed, it drives this point home. If you learn something existed which you would not have suspected existed before, or you discover that you were lied to, or you decide that movie was not as good as you expected it to be, or any number of things that happen to us on a regular basis, you are revising your view of the world and replacing beliefs that you felt were false with beliefs that you now feel are true. Often times we only believe that a thing is true with a certain degree of probability. However we also have also all likely had the experience of believing that something was certainly true, or even fervently believed it to be beyond doubt, but then discovered our beliefs were false. Children start off believing nearly anything their parents tell them, including the belief in Santa Clause and the Easter Bunny if their parents told them about these mythological beings, and tend to believe them fervently. We eventually find out, however, that many of these beliefs are false. We also find out soon enough that our parents can err. Descartes wishes to, as he says, “establish a firm and abiding superstructure of the sciences.” By an “enduring superstructure,” he means that he wishes to build a scaffolding for human knowledge that is certain. One which cannot be doubted and which will not be revised. We can see what he means by way of analogy. Just like a house which is built on a poor foundation will be unstable even if it is otherwise well-built, Descartes is concerned that building our sciences and advanced knowledge on shaky beliefs means that they can all be overturned at any moment. In order to find an absolutely firm foundation, he is going to enter into radical doubt. He says, “I will at length apply myself earnestly and freely to the general overthrow of all my former opinions.” To do this he will withhold belief from any proposition that can by doubted “as if it were certainly false.” The goal is to find something which is impossible to doubt. Something which is so certain he cannot be skeptical about it no matter what lengths he goes to in order to doubt it. The hope is that if he finds something that is impossible to doubt, he would then have a firm foundation on which he can begin to build back up many of his current beliefs. Of course, if we were to try to list all of our beliefs and try to doubt them one by one we would never finish. First, you probably have millions if not hundreds of millions of specific beliefs. Secondly, you have many beliefs that allow you to generate other beliefs without end. For example, you believe that 2 + 2 is 4. Of course you have thought of that equation before. But you may never had added up the specific numbers 10 + 2.5 + 9.9 + .1 + .5 + 7 in that particular order before, and yet after looking at this for a moment you are likely to correctly believe that this sums to 30. In addition, you may never have had the specific thought before about what it would be like to eat 3 pounds of giraffe meat. If not, then you could have not had any belief about doing so prior to this. But, if you imagine such a meal you will probably instantly generate the belief that it would fill you up, even if the thought of doing so also repulses you. Or, another example: You may have never heard of a particular make of Ford truck before, but, once you hear about it, you likely have the belief that if it hit you at 60 miles an hour you would die or at least be severely injured. You manage to have these beliefs because they are based upon other beliefs. This both illustrates why Descartes feels that it is important to make sure that our foundational beliefs are certain and why it is impossible to go through and doubt each of our beliefs individually. Fortunately, for Descartes’ task, he does not need to individually doubt each of his beliefs to see if he can cast doubt onto all of them. He says, “To this end, it will not be necessary for me to show that the whole of these are false---a point, perhaps, which I shall never reach … it will be sufficient to justify the rejection of the whole if I shall find in each some ground for doubt.” In other words, if the beliefs and assumptions that some larger set of beliefs is based upon is called into doubt, then every belief which depends upon that assumption for justification is also cast into doubt. In this way, Descartes can eliminate entire areas of belief all at once. Again we can think of the foundation of a house as a metaphor. If the foundation cracks and begins to sink so does the rest of the house. So, Descartes’ plan then is to doubt the most fundamental beliefs upon which most of his other beliefs rest. We base a large number of our beliefs upon our senses, so he first calls these senses into doubt. Descartes says: “All that I have, up to this moment, accepted as possessed of the highest truth and certainty, I received either from or through the senses. I observed, however, that these sometimes misled us; and it is the part of prudence not to place absolute confidence in that by which we have even once been deceived.” In other words, much of what we take to be truest about the world we have arrived at through our senses. We judge some things to be solid, others to be insubstantial, some to be hot, some to be cold, some to be far away, some to be close, and so forth. But he notes that, though he tends to trust them, his senses have lead him astray in the past. He says that it seems to him that he is sitting by the fire in a winter dressing gown. It seems as if he is holding the paper he is writing on and so forth. But how does he know that he is not insane? People who are insane apparently are plagued with false senses and unable to determine the difference. A grown man might perceive his body as that of a child, or a person in rags might believe herself to be dressed in a gold and lace ball gown. People who are insane often do not realize that they are insane, so how can he be certain that his senses are not fooling him? Perhaps he is somewhere else entirely, and a deluded mind is causing him to believe that he is in a dressing gown, seated by a fire, and writing philosophy. He is also aware that he has in the past had dreams and that while dreaming his senses seemed real. Indeed, he says that he has often dreamt that he was sat by this very fireplace, and was utterly convinced that it was true until he awoke—so how can he know that he is not dreaming? It seems to him as if he is wide awake, but how often has he been fooled by dreams in the past? Since he might be dreaming he will assume that he is. So, what does the possibility that he is dreaming do for his investigations? It allows him to cast aside great swaths of his beliefs at once. Remember that he is rejecting any belief that he can in fact doubt. You should not think that he is crazy here. No doubt that while writing he would do many things that depend upon his senses being accurate. He must have looked at the paper to see the sentences he was producing, he used the feel of the writing implement in his hand to move it around, and, being human, he likely had to eat and relieve himself a number of times while writing. Remember his goal here is to find something that he can believe is certain. He isn’t unable to function in the world as it is, but he has now come to understand that even his most fundamental beliefs can be doubted. He MIGHT be wrong about being by the fire and writing at that very moment. His method of doubt is to reject as if certainly false, that is to say he will refuse to build any ideas on top of, any belief which has any possibility of being false. So, suppose that he is only dreaming? Does this mean that all of his beliefs are cast into doubt? So, what do you think? Is there anything that he can be sure of even if he doesn’t know whether or not he is dreaming or delusional? He is supposing that everything he sees is an illusion. Even that his own hands, limbs, and body are the illusions of a dream. He then says this, “Nevertheless it must be admitted at least that the objects which appear to us in sleep are, as it were, painted representations which could not have been formed unless in the likeness of realities; and, therefore, that those general objects…namely, eyes, a head, hands, and an entire body, are not simply imaginary, but really existent.” In other words, he might be wrong about the nature of his hands, eyes, head and so forth. What he is suggesting is that these objects at least have to exist in the real world for him to have generated the concept in order to dream about them in the first place. In other words, the thought he is entertaining is the idea that he cannot dream about something unless he has seen its likeness before. He might put these things together in new ways and he might tell new stories about them in a dreaming or delusional mind, but, he asks himself, can he not at least assume that items like fires, and hands, and paper must really exist? His analogy is to that of a painter. A painter might paint items that never have existed at all. But a painter who paints, for example, a mermaid, is putting together things that exist to produce the image of something that does not. Fish tails exist, and women exist, and when the two are put together one has an image of a mermaid. But maybe objects such as heads and hands are too complex to assume the existence of. Maybe they are a conglomeration of other existing things like our own example of the mermaid. But what about their basic elements? So, imagine that complex items like a head or hands are possibly fictitious, much like the mermaid or griffin we just saw. He says, “…though these general objects, viz. [a body], eyes, a head, hands, and the like, be imaginary, we are nevertheless absolutely necessitated to admit the reality at least of some other objects still more simple and universal than these… of which all those images of things, whether true and real, or false and fantastic, that are found in our consciousness are formed.” In other words, even if complex objects like our hands or eyes are imaginary can we not at least be sure that colors are real? That shape is real? That extension in space and number are real? These are, after all, the things of which all of our images are constructed. So, do you think, has he found something certain in the existence of color, or shape, or number? It turns out that no, he has not. At this point, the thought experiment gets even more wild. He says that he has long had the thought that there is an all-powerful God who created him. Could this God not have created him such that there is no earth and no sky but that it appears to him to be so? He thinks that an all good being would not do this, but maybe instead there is an evil genius or evil demon, with much the same power, who has taken it as his task to systematically fool Descartes. He says: I will suppose, then, not that Deity, who is sovereignly good and the fountain of truth, but that some malignant demon, who is at once exceedingly potent and deceitful, has employed all his artifice to deceive me; I will suppose that the sky, the air, the earth, colors, figures, sounds, and all external things, are nothing better than the illusions of dreams, by means of which this being has laid snares for my credulity; I will consider myself as without hands, eyes, flesh, blood, or any of the senses…I will continue resolutely fixed in this belief, and if indeed this means it be not in my power to arrive at the knowledge of truth, I shall at least do what is in my power, viz, [ suspend my judgment ], and guard with settled purpose against giving my assent to what is false, and being imposed upon by this deceiver, whatever be his power and artifice.” This means that he cannot even be certain of mathematical facts. We are all familiar with making mathematical mistakes when adding a complex series of numbers, but if there is an evil demon fooling us, we might be wrong every time we add 2 and 2 and get four. We think we count, maybe on a number-line, one, two, three, four, but it is possible that that demon interferes with our thoughts and causes us to make a mistake that we do not notice every time. And, in perhaps despair of discovering anything true at this point, he ends his first meditation shortly thereafter. Meditation 2. The next day he says that he ended the pervious day believing all the things that he sees are fictitious and, not only that, but that none of the objects that present themselves to him actually have any existence in even a non-delusional reality. This includes, color, extension, and even number. He will doubt even the existence of God, and instead supposes that he is being systematically fooled by a similarly powerful but deceitful being. Should he despair? Is there anything about which he cannot doubt? Is there anything that is certain? He says, “But I before denied that I possessed senses or a body; I hesitate, however, for what follows from that? Am I so dependent on the body and the senses that without these I cannot exist? But I had the persuasion that there was absolutely nothing in the world, that there was no sky and no earth, neither minds nor bodies; was I not, therefore, at the same time, persuaded that I did not exist?” So, he is doubting that he even has a body at all. That even the external world exists. By doubting these things does not also doubt his own existence? He says, “Far from it; I assuredly existed, since I was persuaded.” In other words, if he was persuaded that he has no body and that no external world exists, he must exist in order to be persuaded. But what about the demon that is fooling him? What if the demon is only fooling him into believing that he exists? Well, then he must definitely exist because he is being fooled. Descartes says, “But there is I know not what being, who is possessed at once of the highest power and the deepest cunning, who is constantly employing all his ingenuity in deceiving me. Doubtless, then, I exist, since I am deceived; and, let him deceive me as he may, he can never bring it about that I am nothing…” This is where Descartes famous phrase, “Cogito Ergo Sum” comes in. “I think therefore I am.” Not to be confused with, “I am what I am.” What is not a philosopher at all, but Popeye the sailor man. This is pretty much where the reading lets off, but there is a little more that can be said here. Descartes then goes on to ask, though he knows that he exists, what kind of thing he is. He reasons that he is at thinking thing. After all, if he only thinks that he is thinking then he must be thinking. He knows that he exists so long as he is thinking. Most of the rest of the meditations are dedicated to building back up his previous knowledge, but it is the first part of his argument, the part that we just covered, which is taken to be the most successful. His next steps are to give an argument for the existence of God. He then uses the idea that God is good, and no deceiver, to build back up most of his other beliefs based on the idea that God would not systematically deceive him. He might be occasionally wrong in the particulars, but in general his senses are reliable and he can be sure of those things which are clear and distinct to him. The argument he uses for the existence of God is the Ontological Argument for God’s existence. We will discuss arguments for the existence of God later in the semester, but we will see that this argument is far from problem free. But we will end this discussion of Descartes here. What you should take away from this is his method of doubt, how he managed to doubt such large swaths of his ideas, and the purpose of his program of doubt. That is to build a firm foundation on which to base all of human knowledge. It might be worth noting also that though Descartes argued for the existence of God, and though he dedicated his work to the Catholic church, his work was not received well by the church and his books were often banned. His work was viewed as anthropocentric and, quoting from Wikipedia, presenting a worldview in which “the human being is now raised to the level of subject, and agent, and emancipated being equipped with autonomous reason” as opposed to being dependent upon revelational truth. Though the majority of modern research scientists do not believe in god, Descartes in many ways helped to usher in the scientific revolution with is views. He also was very science friendly, for the time, himself. He, arguably, viewed himself as making the world safe for science by delineating realms of study which should be based upon empirical study and not revelation, these being interpretation of the nature of the physical world, and leaving the Church dominion over spiritual matters and matters of the soul which he felt was separate from the body. We will be discussing Cartesian dualism later in the semester as well. And that ends this presentation. Until next time….