Unformatted text preview: Review From Last Time Descartes was a dualist. Descartes dualist A dualist is someone who thinks there are two distinct dualist kinds of substances in the world: physical and nonkinds physical (i.e., mental) substances. Many philosophers are not dualists, but, rather, Many monists. monists A monist is someone who thinks that there is only kind monist of substance in the world. of Monists who think that there are only mental Monists substances are idealists. idealists Monists who think that there are only physical Monists substances are physicalists (or materialists). physicalists materialists Review From Last Time Some monists believe that there are no physical Some substances and that all there are are mental substances. substances. A monist who thinks that the only kinds of substances monist there are in the world are mental substances is an idealist. idealist One famous philosopher who was an idealist was George One Berkeley. Berkeley. Other monists believe that there are no mental Other substances and that all there are are physical substances. substances. A monist who thinks that the only kinds of things there monist are in the world are physical substances is a physicalist (or a materialist). physicalist materialist Most contemporary philosophers are physicalists. Review From Last Time
Armstrong’s Argument For Physicalism (1) Science can explain all of the phenomena in the world. (2) If science can explain all of the phenomena in the world, then If physicalism is true. physicalism (3) Therefore, physicalism is true. 1,2 MP Justification for premise 1: Science, alone, has actually seemed to reach an intellectual consensus Science, about controversial matters and it has explained much of what we used not to know. not Science only studies physical things. So, if science can explain all the phenomena in the world, all the So, phenomena in the world can be explained in terms of physical things. phenomena And so, if science can explain all the phenomena in the world, then the And only things in the world must be physical things. only Justification for premise 2: Review From Last Time Physicalists think that mental states are physical Physicalists states. states. Behaviorists identify mental states with physical behavior. behavior. Problems for behaviorism: The mental states could be absent even though the The behavior was there. behavior The mental states could be there without the behavior. Many physicalists think that mental states are not Many identical with behavior, but, rather, brain states. identical Which brain states are identical with which mental states? Neuroscientific investigation will reveal the answer. Review From Last Time Physicalists attempt to reduce mental states to brain states. A reduction of X to Y is an account of how X is nothing more than Y. reduction Examples of scientific reductions: Water is reduced to H2O. Lightning is reduced to electrical discharge. Genes are reduced to DNA. Physicalists think that one can give a similar kind of reduction of mental Physicalists states to brain states. states Nagel is dubious of this project because he thinks that a Nagel reduction of mental states to brain states can’t account for consciousness, I.e., it can’t account for the subjective or phenomenological character of certain mental states. phenomenological What does it mean to say that an organism is conscious?
To say that X is conscious is to say that there is something that it is like to be X. The “what it is like” to have a certain experience is the subjective character or the phenomenological character of that experience. Philosophy of Mind Nagel’s worry about physicalism is that it Nagel’s seems hard to see how one could give a physical characterization of the subjective character of experience. character “If physicalism is to be defended, the phenomenological features must themselves be given a physical account. But when we examine their subjective character it seems that such a result is impossible. The reason is that every subjective phenomenon is essentially connected with a single point of view, and it seems inevitable that an objective, physical theory will abandon that point of view.” Philosophy of Mind What is it like to be a bat? It is not reasonable to suppose that the phenomenological experience of echolocation is anything like any of our experiences or anything that we can imagine. The resources of our imagination come from our own sense experiences. But we do not have any experiences it is plausible to suppose is phenomenologically like echolocation. So, it seems, we can’t even imagine what it is like to be a bat. But just because we lack the conceptual resources to But imagine what it is like to be a bat should not lead us to think that there is nothing it is like to be a bat. to There is something it is like to be a bat. We just are conceptually incapable of even imagining what it could be like. Philosophy of Mind At first it seems that Nagel is arguing that physicalism must be false: Trying to reduce consciousness to something physical is an attempt to give an objective account of consciousness. An objective account necessarily moves away from the subjective point of view. But the subjective point of view is essential to consciousness. However, in the end, he shies away from that conclusion. He rests with the thought that our conceptual resources He are so limited that we can’t see how physicalism could be true. true. But, perhaps, were we to enrich our conceptual repertoire, we might But, see how it could be true. see Philosophy of Mind In “What Mary Didn’t Know” Frank In Jackson takes a more forceful stance against physicalism. against conclusion that physicalism is false. conclusion “The Knowledge Argument” “The Jackson presents an argument for the Jackson His argument has come to be known as His Philosophy of Mind
Mary the Scientist
“Mary is confined to a black-and-white room, is Mary educated through black-and-white books and through lectures relayed on black-and-white television. In this way she learns everything there is to know about the physical nature of the world. She knows all the physical facts about us and our environment, in a wide sense of ‘physical’ which includes everything in completed physics, chemistry, and neurophysiology, completed and all there is to know about the causal relational facts consequent upon all this…. If physicalism is true, she knows all there is to know. For to suppose otherwise is to suppose that there is more to know than every physical fact, and that is just what physicalism denies.” physicalism Philosophy of Mind
Mary the Scientist (continued) “It seems, however, that Mary does not know It all there is to know. For when she is let out of the black-and-white room or given a color television, she will learn what it is like to see something [peach], say. This is rightly described as learning--she will not say “ho, learning--she hum.” Hence physicalism is false. This is the knowledge argument in one of its manifestations.” manifestations.” Philosophy of Mind
The Knowledge Argument 1. If physicalism is true, then there are no facts If about the world that Mary doesn’t know when she is in the black-and-white. when 2. It is not the case that there are no facts It about the world that Mary doesn’t know when she is in the black-and-white room. when 3. Therefore, it is not the case that physicalism Therefore, is true. is 1,2 MT Philosophy of Mind Justification for premise 1: In the black-and-white room Mary has learned all In of the physical facts about the world. of There is no reason to think that all the physical facts about the There world could be conveyed in black-and-white. world Color textbooks and lectures only seem to make understanding Color certain facts easier, but they don’t seem to be necessary to convey the information about the physical world. convey Physicalism is the doctrine that the only facts there Physicalism are are the physical facts. are So if physicalism is true, since Mary knows all the So physical facts about the world when she is in the black-and-white room, then there are no facts about the world that Mary doesn’t know when she is in the black-and-white room. is Philosophy of Mind Justification for premise 2: When Mary leaves the black-and-white When room she learns something. learns
looks like. looks In particular, she learns what the color peach In But if she learns something, then it must be But that there was some fact that she didn’t know when she was in the black-and-white room. room. Philosophy of Mind How might one reply to the Knowledge Argument?
1. Deny the first premise:
How? Say that Mary has not learned all the physical facts about the world in the black-and-white room. -This is hard to maintain. Why couldn’t she learn all the physical facts from black-andwhite media? white 1. 1. Deny the second premise:
How? Grant that Mary learns something when she leaves Grant the black-and-white room, but deny that what she learns is a new fact about the world. learns
1. 2. Say instead that she has learned a new ability, or Say ability Say instead that she has learned a new way grasping Say a fact she already knew. fact Philosophy of Mind
Is Physicalism true? If so, why? If not, why not? ...
View Full Document