Reading Notes by Christopher Lay

Los Angeles Pierce College

Department of History, Philosophy, and Sociology

Jackson	"What Mary Didn't Know"	Frank Jackson (1986), "What Mary Didn't Know," The Journal of Philosophy, Volume 83, Number 5, pp. 291-295.
Mary	1) Confined to a black-and-white room 2) Educated via black-and-white books 3) Lectured via black-and-white television	"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."
	4) Mary "learns everything there is to know about the physical nature of the world."	"In this way she learns everything there is to know about the physical nature of the world."
What She Knows	Mary knows all the physical facts about humans and their environments. Where physical facts include "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."	"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, and all there is to know about the causal and relational facts consequent upon all this, including of course functional roles."
Physicalism	"If physicalism is true, she knows all there is to know."	"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."
Why?	The actual world "is entirely physical." So, complete physical knowledge is just complete knowledge.	"Physicalism is not the noncontroversial thesis that the actual world is largely physical, but the challenging thesis that it is entirely physical. This is why physicalists must hold that complete physical knowledge is complete knowledge simpliciter."
Ignorance & Education	There are things that Mary doesn't know–yet ... "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 red ... " Upon exiting the room, and entering the world outside, she learns, that is, gains knowledge.	"It seems, however, that Mary does not know 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 red, say. This is rightly described as learning–she will not say 'ho, hum.'"
The "Knowledge Argument"	"Hence, physicalism is false." "This is the knowledge argument against physicalism in one of its manifestations."
I.	"Three Clarifications"
Clarification Number One / Imagination	"Powers of imagination are not to the point."	"The knowledge argument does not rest on the dubious claim that logically you cannot imagine what sensing red is like unless you have sensed red. Powers of imagination are not to the point."
	The claim is not that Mary "could not imagine" what it is like. The claim is that Mary "would not know" what it is like.	"The contention about Mary is not that, despite her fantastic grasp of neurophysiology and everything else physical, she could not imagine what it is like to sense red; it is that, as a matter of fact, she would not know."
	If complete knowledge of the physical world is all that is needed to know everything, then Mary wouldn't need imagination. "Imagination is a faculty that those who lack knowledge need to fall back on."	"But if physicalism is true, she would know; and no great powers of imagination would be called for. Imagination is a faculty that those who lack knowledge need to fall back on."
Clarification Number Two / Intensionality of Knowledge	Likewise, the "intensionality of knowledge is not to the point."	"Secondly, the intensionality of knowledge is not to the point."
	The argument doesn't rest on this false assumption: If Mary knows, "that a is F and if a = b, then [Mary] knows that b is F."	"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."
		"It is concerned with the nature of Mary's total body of knowledge before she is released: is it complete, or do some facts escape it?"
	If Mary's ignorance was such that she did not know that b is F (while knowing "that a is F and if a = b") because she was not smart enough to follow logical consequences out, then her ignorance would not be a threat to physicalism.	"What is to the point is that [Mary] may know that a is F and know that a = b, yet arguably not know that b is F, by virtue of not being sufficiently logically alert to follow the consequences through." "If Mary's lack of knowledge were at all like this, there would be no threat to physicalism in it."
	"But it is very hard to believe that her lack of knowledge could be remedied merely by her explicitly following through enough logical consequences of her vast physical knowledge."
	"Endowing her with great logical acumen and persistence is not in itself enough to fill in the gaps in her knowledge."
	"On being let out, she will not say 'I could have worked all this out before by making some more purely logical inferences.'"
Clarification Number Three / Knowledge of Others' Mental States	Mary's ignorance, while in the room, pertained to the knowledge she lacked about other people's mental states.	"Thirdly, the knowledge Mary lacked which is of particular point for the knowledge argument against physicalism is knowledge about the experiences of others, not about her own."
	Sure, when she emerges, she has never-had-before experiences.	"When she is let out, she has new experiences, color experiences she has never had before."
		"It is not, therefore, an objection to physicalism that she learns something on being let out. Before she was let out, she could not have known facts about her experience of red, for there were no such facts to know. That physicalist and nonphysicalist alike can agree on."
	Physicalism can still be correct if Mary learns something about herself, since physical parts of her changed upon emerging.	"After she is let out, things change; and physicalism can happily admit that she learns this; after all, some physical things will change, for instance, her brain states and their functional roles."
	But ... "The trouble for physicalism is that, after Mary sees her first ripe tomato, she will realize how impoverished her conception of the mental life of others has been all along."
Ignorance of Others'	"She will realize that there was, all the time she was carrying out her laborious investigations into the neurophysiologies of others and into the functional roles of their internal states, something about these people she was quite unaware of."
		"All along their experiences (or many of them, those got from tomatoes, the sky, . . .) had a feature conspicuous to them but until now hidden from her (in fact, not in logic)."
		"But she knew all the physical facts about them all along; hence, what she did not know until her release is not a physical fact about their experiences. But it is a fact about them. That is the trouble for physicalism."
II.	"Churchland's Three Objections"
(i)	Objection: "The argument equivocates on the sense of 'knows about.'"	"Churchland's first objection is that the knowledge argument contains a defect that 'is simplicity itself.' The argument equivocates on the sense of 'knows about.'"
	Consider this, Churchland's, version of the argument:	"Churchland suggests that the following is 'a conveniently tightened version' of the knowledge argument:
Premise One	"(1) Mary knows everything there is to know about brain states and their properties."
Premise Two	"(2) It is not the case that Mary knows everything there is to know about sensations and their properties."
Conclusion	"Therefore, by Leibniz's law [From Stanford Encyclopedia of Philosophy: "no two distinct things exactly resemble each other"], "(3) Sensations and their properties ≠ brain states and their properties."
Problem	The kinds of knowledge in the two premises are different.	"Churchland observes, plausibly enough, that the type or kind of knowledge involved in premise 1 is distinct from the kind of knowledge involved in premise 2."
	Premise One Knowledge = knowledge by description Premise Two Knowledge = knowledge by acquaintance	"We might follow his lead and tag the first 'knowledge by description,' and the second 'knowledge by acquaintance;' but, whatever the tags, he is right that the displayed argument involves a highly dubious use of Leibniz's law."
Jackson's Reply	The presented argument is not his, Jackson's, argument. Straw-man fallacy	"My reply is that the displayed argument may be convenient, but it is not accurate. It is not the knowledge argument."
	The first premise is not in Jackson's argument. It is not that Mary knows all there is to know about brain states and their properties, rather, Mary is supposed to know all there is about the physical world.	"Take, for instance, premise 1.The whole thrust of the knowledge argument is that Mary (before her release) does not know everything there is to know about brain states and their properties, because she does not know about certain qualia associated with them."
	"What is complete, according to the argument, is her knowledge of matters physical."
Jackson's Argument	Here's how Jackson summarizes his own argument: "(1)' Mary (before her release) knows everything physical there is to know about other people"	"A convenient and accurate way of displaying the argument is:"
	"(2)' Mary (before her release) does not know everything there is to know about other people (because she learns something about them on her release)"
	"Therefore, "(3)' There are truths about other people (and herself) which escape the physicalist story."
Not Kinds of Knowledge, but What's Known	So, it is not about the kind of knowledge Mary has, but rather about what Mary knows.	"What is immediately to the point is not the kind, manner, or type of knowledge Mary has, but what she knows. What she knows beforehand is ex hypothesi everything physical there is to know, but is it everything there is to know? That is the crucial question."
A Relevant Worry	But there is a relevant worry: Not with a premise, but with the support for a premise, premise 2' "The case for premise 2' is that Mary learns something on her release, she acquires knowledge, and that entails that her knowledge beforehand (what she knew, never mind whether by description, acquaintance, or whatever) was incomplete."	"There is, though, a relevant challenge involving questions about kinds of knowledge. It concerns the support for premise 2'."
No New Knowledge	A challenge from this worry: "on her release Mary does not learn something or acquire knowledge in the relevant sense."	"The challenge, mounted by David Lewis and Laurence Nemirow, is that on her release Mary does not learn something or acquire knowledge in the relevant sense."
Ability, not Knowledge Acquired	"What Mary acquires when she is released is a certain representational or imaginative ability;" "it is knowledge how rather than knowledge that."
	Yes, Mary acquired something, an ability, but this does not impugn the knowledge she had prior to emerging from the room.	"Hence, a physicalist can admit that Mary acquires something very significant of a knowledge kind–which can hardly be denied–without admitting that this shows that her earlier factual knowledge is defective."
	"She knew all that there was to know about the experiences of others beforehand, but lacked an ability until after her release."
Abilities Admission	Sure, Jackson counters, Mary'll acquire some abilities after emerging from the room. She'll be able to imagine and remember what it is like to see red.	"Now it is certainly true that Mary will acquire abilities of various kinds after her release. She will, for instance, be able to imagine what seeing red is like, be able to remember what it is like, and be able to understand why her friends regarded her as so deprived (something which, until her release, had always mystified her)."
	"But is it plausible that that is all she will acquire?"
	To answer that, Jackson proposes an altered thought experiment: While Mary was schooled on physicalism, she was also given a lecture on skepticism about other minds.	"Suppose she received a lecture on skepticism about other minds while she was incarcerated."
	As with the earlier version, when she exits the room and sees red for the first time, Mary no.w says she knows more about the experiences of others when they see the color red	"On her release she sees a ripe tomato in normal conditions, and so has a sensation of red" "Her first reaction is to say that she now knows more about the kind of experiences others have when looking at ripe tomatoes"
	But then she recalls the lecture on other minds skepticism, and asks herself: Do I "really know more about what their experiences are like, or [am I] indulging in a wild generalization from one case?"	"She then remembers the lecture and starts to worry"
	"In the end she decides she does know, and that skepticism is mistaken (even if, like so many of us, she is not sure how to demonstrate its errors)."
	What was Mary hemming and hawing about?	"What was she to-ing and fro-ing about–her abilities?"
	Jackson argues that she was not wondering about her abilities.	"Surely not; her representational abilities were a known constant throughout. What else then was she agonizing about than whether or not she had gained factual knowledge of others?"
	"There would be nothing to agonize about if ability was all she acquired on her release."
	While Jackson admits that his argument lacks certitude, he argues that:	"I grant that I have no proof that Mary acquires on her release, as well as abilities, factual knowledge about the experiences of others–and not just because I have no disproof of skepticism."
	His "claim is that the knowledge argument is a valid argument from highly plausible, though admittedly not demonstrable, premises to the conclusion that physicalism is false." "And that, after all, is about as good an objection as one could expect in this area of philosophy."
(ii)	Churchland argues that Jackson's knowledge argument ... proves too much.	"Churchland's second objection is that there must be something wrong with the argument, for it proves too much."
	Suppose Mary receives lectures about dualism. The "laws" of dualism are explained.	"Suppose Mary received a special series of lectures over her black-and-white television from a full-blown dualist, explaining the 'laws' governing the behavior of 'ectoplasm' and telling her about qualia."
	"This would not affect the plausibility of the claim that on her release she learns something. So if the argument works against physicalism, it works against dualism too."
Jackson's Reply	Lectures about "what it is like" do not inform her about all there is to know about "what it is like."	"My reply is that lectures about qualia over black-and-white television do not tell Mary all there is to know about qualia."
	The lectures will tell her some things about "what it is like" to see red, e.g. that what it is like to see red is different from what it is like to see blue.	"They may tell her some things about qualia, for instance, that they do not appear in the physicalist's story, and that the quale we use 'yellow' for is nearly as different from the one we use 'blue' for as is white from black."
	While the lectures can inform Mary everything about physics and physicalism, it cannot inform here everything about "what it is like."	"But why should it be supposed that they tell her everything about qualia? On the other hand, it is plausible that lectures over black-and-white television might in principle tell Mary everything in the physicalist's story."
		"You do not need color television to learn physics or functionalist psychology."
	The full story of physicalism can be given her in the room, but ... The full story of dualism cannot be given to her in the room.	"To obtain a good argument against dualism (attribute dualism; ectoplasm is a bit of fun), the premise in the knowledge argument that Mary has the full story according to physicalism before her release, has to be replaced by a premise that she has the full story according to dualism."
		"The former is plausible; the latter is not."
	"Hence, there is no 'parity of reasons' trouble for dualists who use the knowledge argument."
(iii)	"Churchland's third objection is that the knowledge argument claims 'that Mary could not even imagine what the relevant experience would be like, despite her exhaustive neuroscientific knowledge, and hence must still be missing certain crucial information,' a claim he goes on to argue against."
	"But, as we emphasized earlier, the knowledge argument claims that Mary would not know what the relevant experience is like." "What she could imagine is another matter." "If her knowledge is defective, despite being all there is to know according to physicalism, then physicalism is false, whatever her powers of imagination."