The Knowledge Argument What Mary Didn’t Know Frank Jackson What Mary doesn’t know • Mary is confined to a black-and-white room, is educated through black-and-white books and through lectures relayed on black and white television…She knows all the hysical facts about us and our environment, in a wide sense of „physical‟ which includes everything in completed physics, chemistry, and neurophysiology, and all there is to know about the causal and relational facts consequent upon all this, including of course functional roles. • If physicalism is true, she knows all there is to know. For to suppose otherwise, that there is more to know than every physical fact, and that is just what physicalism denies. Argument against Physicalism • The knowledge argument aims to establish that conscious experience involves non-physical facts. • It rests on the idea that someone who has complete physical knowledge about the world might yet lack knowledge about what conscious experience is like “from the inside.” What the Argument is Not • Not an argument for the Empiricist doctrine that “all knowledge comes from experience” • Not an argument for the intensionality of knowledge – The argument does not rest on assuming falsely that, if S knows that a is F and if a = b, then S knows that b is F…on being let out, she will not say „I could have worked all this out before by making some more purely logical inferences. • Not an argument for Substance Dualism or the possibility of post-mortem survival The structure of the Argument • The Knowledge Intuition – Conscious experience is “knowing what it is like…” – Knowing all the physical facts about experience (from the 3rd person perspective) is not enough to know “what it is like” to have that experience • The Knowledge Intuition entails the falsity of physicalism. Physicalism • The thesis that everything is physical, a.k.a materialism • A complete physics will explain all facts about the world • psychological or biological or social features of the world supervene on physical facts about the world. Lewis on Supervenience • A dot-matrix picture has global properties … yet all there is to the picture is dots and non-dots at each point of the matrix. • The global properties are nothing but patterns in the dots. • They supervene: no two pictures could differ in their global properties without differing, somewhere, in whether there is or there isn't a dot Supervenience • What these hedges are like at the leaf-and-branch level determines what the topiary looks like • But hedges that were different at the leaf-and-branch level could have the same topiary look More Supervenience • Supervenience entered philosophy initially in ethics. • Moral properties were said to supervene upon non-moral properties • In general, value is supervenient • So, supervenience isn’t just a matter of spatially large-scale properties depending on spatially small-scale properties. Physicalism: a fact about our world? • Physicalism is true at a possible world w iff any world which is a physical duplicate of w is a duplicate of w simpliciter. • Physicalism is usually taken to be a matter of contingent fact • There are worlds at which there are non-physical facts but (according to physicalists) ours isn’t one of them. Physicalism: Pro • Naturalism as an aggressor hypothesis – E.g. explaining life in naturalistic terms • The reducibility of psychological, biological and other explanations to physical explanations • The elimination of irreducible agency explanations Physicalism: Con QUALIA! The History of an Intuition • C. D. Broad’s Archangel • Feigl’s Martian • Thomas Nagel’s Bat Broad’s Archangel He would know exactly what the microscopic structure of ammonia must be; but he would be totally unable to predict that a substance with this structure must smell as ammonia does when it gets into the human nose…[H]e could not possibly know that these changes would be accompanied by the appearance of a smell in general or of the peculiar smell of ammonia in particular, unless someone told him so or he had smelled it for himself. NH3 Feigl’s Martian Could a Martian, entirely without sentiments of compassion and piety, know about what is going on during a commemoration of the armistice?…[He could] predict all responses, including the linguistic utterances of the earthlings in the situations which involve their visual perceptions, their laughter about jokes, or their (solemn) behavior at the commemoration. But ex hypothesi, the Martian would be lacking completely in the sort of imagery and empathy which depends on familiarity (direct acquaintance) with the kinds of qualia to be imaged or empathized Nagel’s Bat • Nagel in “What It Is Like to Be a Bat” argues that some facts can only be captured „from a subjective perspective‟ and uses his example of bats to illustrate the point • Even if we knew everything there is to know „from an objective perspective‟ about a bat's sonar system we still would not know „what it is like‟ to perceive a given object with a bat's sonar system. Inconclusive • These examples just pump the “knowledge intuition” but are inconclusive • It is debatable whether these archangels or Martians are missing something in the first place • We can’t imagine what it’s like to be a bat because we’re physically very different--lack of imagination doesn’t show anything. • The crucial feature of the Knowledge Argument is that Mary learns something. Jackson’s next step • To make the case against physicalism we need to show that – An individual that knows all the physical facts – Might still be lacking knowledge of some facts • This would show that the physical facts are not all the facts there are. Mary in the black and white room Mary is a brilliant scientist who is…forced to investigate the world from a black and white room via a black and white television monitor. She specializes in the neurophysiology of vision and acquires…all the physical information there is to obtain about what goes on when we see ripe tomatoes…and use terms like „red‟… Mary gets out! • [W]hen Mary is released from her black and white room…It seems just obvious that she will learn something about the world and our visual experience of it. • But then is it inescapable that her previous knowledge was incomplete. • But she had all the physical information. • Ergo there is more to have than that, and Physicalism is false. The Knowledge Argument • Mary knows all the physical facts concerning human color vision before her release. • But there are some facts about human color vision that Mary does not know before her release. • So, there are non-physical facts concerning human color vision. Objections to the Argument • The success of the argument hinges on whether Mary acquires new propositional knowledge. • So we ask: – Is it new knowledge and – Is it propositional knowledge, as distinct from, e.g. know-how or “knowledge by acquaintance” Propositional Knowledge • Knowing that as distinct from knowing how, knowing who, etc. • Expressed by “x knows that ______” where a proposition fills the blank. • This is knowledge of facts…and that’s what we need for the argument to go through since the claim is that there are non- physical facts about the world. Objection: Mary acquires know- how rather than know that • Knowing that is neither necessary nor sufficient for know-how – I know lots about music theory and about the theory of piano playing but I can’t play – I’m a fluent native English speaker but can’t explain the grammar • After getting out of the room, Mary acquires new skills – As I would if I practiced! • But she doesn’t acquire any new factual knowledge. Response to the Know-How Objection • Now it is certainly true that Mary will acquire abilities of various kinds after her release…But is it plausible that that is all she will acquire? • I grant that I have no proof that Mary acquires on her release, as well as abilities, factual knowledge…My claim is that the knowledge argument is a valid argument from highly plausible, though admittedly not demonstrable, premises. The Argument Proves Too Much Objection • Suppose that prior to her release Mary is a Dualist who knows all there is to know about “ectoplasm” • Mary still learns something so • The argument cuts against dualism as much as it does against physicalism Response to the Proves Too Much Objection • We aren’t defending Cartesian Dualism here or arguing for the existence of “ectoplasm” • If, in the revised thought experiment, Mary learns something new after getting out then she doesn‟t know all there is to know about dualism The Failure of Imagination Objection • Before getting out, Mary couldn’t even imagine what it would be like to, e.g. see red • So she didn’t really have all the information about the physical facts of the matter, contrary to the assumption. Response to the Failure of Imagination Objection • Failure of imagination is neither here nor there • This is really a return to the what it is like to be a bat argument • The point is that she didn’t know what it was like Objection: If we reject Physicalism we’re stuck with Epiphenomenalism • The physical world is a closed system so • If there are non-physical events/states they make no difference they’re causally idle • Which is to say, we’re stuck with Epiphenomenalism Jackson’s Response c. 1993 Epiphenomenalism is fine by me And then… • Jackson changed his mind • The argument, he said, contained no obvious fallacy and yet its conclusion--that physicalism is false--must be mistaken. • Since the conclusion is false, there must be something wrong with the argument--something we know not what! One man’s modus ponens-- is another man’s modus tollens If it’s not worth doing well it’s not worth doing at all • If the Knowledge Argument is sound then Physicalism is false • But Physicalism is not false, therefore the Knowledge Argument is not sound--for whatever reason. • Giving up Physicalism is too high a price to pay to accommodate our intuitions about qualia. Should we be Physicalists? • Benefits: modern science has within it a certain picture of the world…best distilled as the thesis of physicalism…[and]it is a methodological mistake to suppose that philosophy itself should revise science. • Costs: Physicalism apparently is counter to our intuitions about values, free-will, experience and a variety of other issues. Sometimes our intuitions are just lousy George Wilson warning us that intuitions are not decisive How high are the costs? • Even if we ditch our “intuitions” about values, experience, free- will, etc. we can still: – Make moral and aesthetic judgments – Talk about feelings and emotions – Distinguish intentional from unintentional actions and hold people responsible • We just cash out these claims differently • Philosophy is analysis: it is concerned with cashing out such claims--not with revealing truths about the universe or the human condition.
Pages to are hidden for
"mary"Please download to view full document