Descartes and the First Two Meditations 9/15 I. Descartes Motivations - Descartes begins the meditations by mentioning that he was taught and accepted many falsehoods in his youth, and that his beliefs were built on false foundations. -He says he wants to tear down his old beliefs and begin again from new foundations. -Why? A. The Scientific Revolution -writing during the scientific revolution - born shortly after Copernicus dies -was a contemporary of Galilieo and Kepler. 1) The conflict between religious world-view and science a) Example: Story of Galileo -found guilty of impiety in 1632 for publishing paper on 4 moons orbiting jupiter--why? -Church view: earth was at center of universe, created and placed there by god -hence human drama was also at the center of universe and all human life was significant -Copernicus heliocentric model of solar system challenged this. -the church had one remaining bit of supporting evidence: the moon revolved around the earth. -Galileo showed that sun can be center of solar system while moons can orbit planets. -What happens to human significance? b) matter, motion and mechanical laws -according to the new science, the only substance in the world was matter, and matter behaved according to strict laws of nature that could be codified mathematically. -if all is matter, what happened to the human soul? -if all change occurs according to strict mechanical laws, what happens to human freedom? B. Descartes, a Man in Conflict -was at once a man of science but also a man of religion. -wanted to reconcile new science with existence of God, the human soul, human freedom, and ultimately, human significance. -**Method of Doubt very appropriate for a man in conflict like this--doubt everything and begin anew. So how does Descartes doubt everything? II. The Skeptical Argument A. Global Doubt: no need to doubt beliefs one-by-one; rather, former beliefs rested on a foundation of information from sensory experience; if he can question the legitimacy of the transition from this information to his former beliefs, then he can undermine all his former beliefs at once. -***what better way to do this than to suppose it possible that all his sensory information could be exactly how it is right now, while the world is completely different? B. A Paradigm or Best-Case Argument: give analogy with discovering properties of H2O.
-Put himself in the best possible position to know, and if he cannot know there he cannot know anywhere. -best possible position: sitting by the fire in his jammies. C. Dreaming/Brain-in-a-vat/Matrix Argument -Descartes cannot know he is sitting by fire unless he can rule out possibility that he is dreaming. -If he cannot know that he is not dreaming, how can he know that he is awake sitting by the fire in his jammies? -any test that he could use to determine whether he is dreaming could itself be a dream; he cannot distinguish dreaming-life from waking life, so he cannot know that he is not dreaming. -and if he cannot know that he is not dreaming, how can he know that he is sitting by the fire in his jammies; and if he cannot know that he is sitting by the fire in his jammies, how can he lay claim to know anything else about the world around him. **probability doesn t matter, just the possibility that he cannot eliminate. -If you do not know whether you are a brain-in-a-vat/in the matrix, how can you claim to know that you are sitting in class listening to me? D. Formalizing the Argument: the deductive closure principle 1) the principle: If S knows that P, and S knows that P logically entails Q, then S knows that Q. 2) examples: a) If Sally knows that Jane s car is red, and she knows that this entails that Jane s car is not blue, then Sally knows that Jane s car is not blue. -Suppose that Sally doesn t know that Jane s car is not blue--how could she know that Jane s car is red? b) If Sally knows that the earth revolves around the sun, and she knows that this entails that the earth moves, then Sally knows that the earth moves. -Suppose Sally does not know that the earth moves--how could she know that the earth revolves around the sun? -c) If Descartes knows that he is awake and sitting by the fire, and he knows that this entails that he is not dreaming, then he knows he is not dreaming. -Descartes does not know he is not dreaming-- hence, he does not know he is awake and sitting by the fire. -d) If you know that you have two hands, and you know that this entails you are not a brainin-a-vat, then you know that you are not a brain-in-a-vat. -You do not know you are not a brain-in-a-vat; hence you do not know that you have two hands. E. The same evidence version -how do I know I have two hands? -sensory experiences. -but I d have those very same experiences if I were a brain-in-a-vat. -how, then, could those experiences count as evidence for my belief that I have two hands? **thus, I have no justification for believing this at all. F. The Evil Demon: Designed for 3 reasons 1) In dreams we have images, but it is natural to think those images are based on confrontations with real things in waking life. Hence the dreaming scenario alone cannot suffice for radical doubt. Aren t there real things from which my dreamt images arise? To account for this, Descartes supposes that none of what he dreams is based on reality but are instead are the
products of an evil demon who uses all his powers to deceive him. The evil demon is, really, the vat meister. 2) reality is coherent, spacious and majestic, dreams are incoherent, jerky and spasmodic; but perhaps the evil demon deceives us into thinking that so-called waking-life is coherent and majestic. 3) to call into question mathematical reasoning. III. Cogito, Ergo Sum: I think, therefore I am -A. The Argument: Descartes realizes that amidst his seas of doubt, there is one thing of which he can be certain: his own existence. Why? -Really, the occurrence of thought guarantees the existence of the thinker. -if Descartes tries to doubt his own existence, he realizes he must exist to do so, so he cannot doubt his own existence. -if Descartes is being deceived by an evil demon, he must exist to be deceived. **The proposition I am, I exist must be necessarily true if he is thinking it. B. Criticisms of the Argument 1) Lichtenberg -Descartes is not entitled to refer to himself in the context of radical doubt and claim that he thinks, therefore he exists. Rather, says Lichtenberg, all Descartes should be able to conclude is there is thought going on. 2) Russell: a better criticism: -Descartes uses the phrase I think therefore I am or I am, I exist to establish his own existence. The problem is, he needs to refer to himself with I in order to do so. So he is assuming his own existence enroute to proving it. Hence, Descartes argument begs the question. Russell, like Lichtenberg, argues that Descartes is merely entitled to say There are thoughts. a) Blackburn s response: there cannot be thoughts without someone to do the thinking. Thoughts do not float free of people who do the thinking. Really, the response is that thoughts have a subjective quality, are owned or inherently stamped with ownership. Any thought that occurs necessarily has a subjective quality that implies the existence of a thinker. So the use of I merely denotes this subjective character of thought, without referring to anything more substantive. IV. What is the I, the self?: two ways to construe the argument A. Version 1: Methodology: Descartes will subtract away everything that he previously believed himself to be by--once again--doubting everything he can; whatever remains will be what he is-- his essence, the I. -he previously thought he had a body that was noursihed and could move, and that sensed the world around him, but he can easily doubt whether he had a body, and thus whether it could sense, be noursihed, or mobile. **what remains, what he cannot doubt about himself, is that he is a thinking thing. -Hence, what he is is a thinking thing, not a body. 1) Committs what we call the masked man fallacy: -I know who my father is. I don t know who the masked man is. Hence, my father is not the masked man. -I know that prozac is an anti-depressant. I do not know that fluoxetene is an anti-depressant. Hence prozac is not fluoxetene.
-I know that I am a thinking thing. I do not know that I have a body. Hence, I am not a body. B. Version 2: Descartes can be certain that he is a thinking thing while doubting that he has a body. Hence, his knowledge of himself does not depend upon his knowledge of bodies--or anything else, for that matter. See p. 119 column 2. **his conception of himself as a thinking thing is self-evident (or self-justified) and indubitable. He does not infer his knowledge of his own existence from some other knowledge--e.g. knowledge of his body. He has non-inferential knowledge of himself. (foundationalism). C. Foundationalism: the view that all knowledge (justified true belief) rests on a foundation of self-justified true belief, or beliefs that need not be justified by any other beliefs. -1.empirical foundationalism: empirical beliefs, or beliefs about one s own sense experience, are the basic, self-justified beliefs. For example, if I a looking at a tomato, my basic empirical belief might be: I believe that I am experiencing something roundish and red in the center of my visual field. I do not infer this belief from any other knowledge; it is given to me directly in experience. -2. Descartes is a rational foundationalist: basic beliefs, such as that I exist, are certified by reason alone. V. The Ball of Wax A. What s the point?: perhaps to resolve this paradox: How can we be so uncertain of the existence of the physical bodies yet feel like we understand them so well, while being absolutely certain about the existence of the self, which we don t understand at all? -to resolve the paradox, Descartes considers a physical object--a piece of wax--and purports to show that the wax is grasped by the mind, not the senses: all of his sensory experiences of the wax change entirely as he moves the wax closer to the fire, yet he still grasps that it is the same piece of wax -how does he still grasp that it is the same piece of wax, when what he sees, hears, feels, tastes and smells changes entirely? -Descartes reasons that he couldn t grasp what the wax is with his sensory perceptons; he grasps it, rather, with the intellect alone--pure mental scrutiny of the wax itself. -the resolution of the paradox: he thought he understood physical objects so well because he grasped them through his senses, but he s just shown that he doesn t grasp physical objects through sense experience at all. He was confused. And what he grasps of the wax with the mind--its essence--is no more describable than what he grasps of himself; so why should the self be any more mysterious than the physical objects? -Moreover, his grasp of the wax reveals his own existence even more, for if he understands the wax, then there must be a mind to do the understanding; and he just learned one important property of this so-called mysterious mind-- namely, that he attains knowledge through the scrutiny of objects with the intellect alone. B. Rationalism and Innate Ideas -this is the view that knowledge is primarily attained by the intellect or reason and not through sense experience--or at least not through sense experience alone; this is usually taken together with the thesis that there are innate ideas, or ideas that the mind comes equipped with and are not acquired through sense experience. (contrast this with empiricism, which is the view that all our ideas come from experience and that no proposition can be known independently of experience).
-For Descartes, although our experiences of the wax change, we still grasp that it is the same thing; we must have, therefore, ideas of sameness or identity, and thingness or substance. And since we didn t acquire them through sense experience, they must be innate concepts. **note that the idea of the self should be added to identity and substance on the list of innate ideas.