What Mary Didn't Know (1986) [pdf]

https://courses.physics.illinois.edu/phys419/sp2021/Jackson1986_WhatMaryDidntKnow.pdf

by kelseyfrog • 3 years ago

39 60 3 years ago

courses.physics.illinois.edu

goatlover6• 3 years ago

Related to this would be Nagel's paper, "What Is It Like to Be a Bat?" We can't say what sort of echolocation sensation a bat has anymore than Mary can say what a color looks like before she leaves the black and white room. We're in the same position when it comes to bird vision. We can't say what the world would look like with four primary colors. What does that fourth primary color look like? We don't have a word for it because we don't see that color.

Or for that matter, what would the rest of the EM spectrum look like if we could see it all? What would a scientific theory that could answer these sorts of questions look like?

Saying physicalism is false because it can't answer the questions above is not to say naturalism is false. There's no magic or supernatural stuff here. It just means our scientific description of the world lacks the subjective. There is a fundamental epistemological limit to our ability to know how to combine the two. It doesn't mean the world itself has such a division. We just can't cognate how to reconcile the two.

Khelavaster• 3 years ago

I'm pretty sure detailed enough differential brain imaging of bats echolocating and not in different circumstances would eventually reveal the secrets of bat echolocation processing.

goatlover6• 3 years ago

And how would that processing tell us what sort of sensation that bat has when using echolocation? Do you think doing this for birds would reveal what the fourth primary color looks like? If the answer is it wouldn't look like anything (for us), then there's something science can't tell us.

tshaddox2• 3 years ago

There is a fundamental epistemological limit to our ability to know how to combine the two. It doesn't mean the world itself has such a division. We just can't cognate how to reconcile the two.

I’m not convinced there’s any indication of a fundamental limit to our cognitive abilities. What if we just don’t know how subjective experience works in the same normal way that we’ve not known how other stuff works until we figured it out?

goatlover6• 3 years ago

I don't know either, it's just that the problem seems to be hard in a fundamental way. We would have to show how something like brain processing results in subjective experience in a way that isn't just correlation. The explanation would somehow have to show how the subjective emerges. How it's determined by the physical processes.

Then we could go make computers conscious.

HEmanZ• 3 years ago

You’ll end up in a category of your own if you “figure out” subjective experience. You’d be the greatest philosopher that ever lived.

It’s not the same problem as figuring out how the brain works physically or how subjective experiences compare in peoples brains or observable states, but whether say our experience of seeing red is the same. Or what it’s like to be a bat. You can’t break that barrier, there is not observation into another subjective. It’s like Heisenberg Uncertainty, at a certain point we reach the unobservable and by the nature of our existence can’t know what’s beyond.

EdwardDiego• 3 years ago

On an aside, I've always loved the idea of a computer game where your character's primary sense is smell.

But how could you really convey it to a human, except visually? Although maybe something like Hellblade: Senua's Sacrifice's audio hallucinations could be a way, whispering voices that tell you the scent blows stronger this way.

SilasX• 3 years ago

Legend of Zelda: Twilight Princess does something like this, where you play as a wolf at some point that can you track in-world smells. Kind of a blunt approach though -- the smell appears with a visual indicator that is absent when you're human.

31337Logic5• 3 years ago

Points for mentioning Hellblade. ;-)

User23• 3 years ago

Human tetrachromats do exist, but it’s X recessive. They can differentiate some hues that others can’t.

goatlover6• 3 years ago

I have heard that. Problem is they can't tell us what those hues are. I suppose they could make up new color words, but it won't tell us what those hues look like.

lynx232• 3 years ago

I use echolocation all the time. Granted, I can definitely not explain how a bat feels, but... I was born with 20% vision, and kept it for roughly 6 years. After that, the world officially went dark. However, my brain was quite stubborn in not accepting that. From that point on, my auditory system, in particular echolocation, took over. My internal field of vision did not change much. Echolocation, and my prior knowledge of the world, was used to build up my idea of my surroundings. At first, that built-up internal image resembled very much how I saw the world prior to going blind. However, after a few years, things started to become abstract. I lost almost all notion of clear-cut edges, and color "perception" smeared itself all over the color spectrum. These days, what I see in my minds eye doesnt really reflect what a sighted person would visualize. However, my minds eye still has the same function, it creates my surroundings in my head such that I can navigate and interact with the world.

goatlover6• 3 years ago

That's very interesting. Bat neuroscience might be able to tell us whether bats use echolocation in a similar fashion as you described (they do also have ears and eyes, although many don't have color vision). If not, then probably they have an entirely different experience that humans when using echolocation.

atdixon2• 3 years ago

We don’t have a word for it because we don’t see that color.

I think you’re missing the argument.

We can easily assign words to things we know exist. That’s not the issue.

When we define things (like “naturalism”) we are invoking symbols and their semantics, all the stuff Mary presumably has access to in her room.

In her room, Mary already understands subjective experience, the brain mechanics behind it, etc.

The realization that there is more outside of Mary’s room suggests that our conceptualizations are limited / not accurate.

If that’s the agreed case how can anyone cling to a universal “naturalism” with a straight face?

With Mary’s room, haven’t we already accepted that formal statements are incomplete - and therefore would be silly to call universal?

gpderetta• 3 years ago

Words don't excite the same bits of our brains as other physical experiences, so full knowledge of red through words and higher level thoughts is not enough for Mary. But assuming she has perfect knowledge of the the interaction of red wavelength with the eye and perfect knowledge of how the sensory input interacts with her brain, she could stick theoretically optimal electrodes in exactly the right places (or specifically tailored psychedelic drugs) and virtually experience and learn about red before actually seeing it.

moremetadata• 3 years ago

We can't say what sort of echolocation sensation a bat has anymore than Mary can say what a color looks like before she leaves the black and white room.

Actually we can. For example, there are reports of the older generation dreaming in black and white due to the black and white tv [1], in much the same way, the days event can shape the dreams someone has. On the physical side, because science is now showing how light and other environmental stimuli affect chemical processes in the body and brain [2,3,4], science is not only discovering the ability to emit and measure, but then find instances in nature where its being used.

what would the rest of the EM spectrum look like if we could see it all

Ultraviolent is a good example, the lens of the eye tends to block this, but people with no lens due to early cataract operations which just removed the lens, and anomalous lens have reported seeing UV light. [5,6]

What would a scientific theory that could answer these sorts of questions look like?

So it depends on whether experts take reports seriously or not, experts applying real scientific conjecture, and/or whether funding and permission can be obtained. We can all detect Infrared (heat) through our skin, but we cant really see it. On another point, which perhaps best describes and exemplifies the boiling frog syndrome is the fact that UV destroys folates, yet we dont really detect as it takes place because its taking place over a larger perceptible window of time [7], at best those suffering from SAD or depression may feel better after a session in the tanning salon or by the end of the tanning session depending on how much UVA light the flo tubes are chucking out. It also highlights that some vegetables like Brussel Sprouts a vegetable high in folates may be harmful to your mental health during winter months, especially considering its a stable for Xmas dinners. But back to the point of what would a scientific theory look like, we already see that ad-hoc practice in action in the scientific world. Generate, Detect, Search for examples, Elucidate, Pontificate.

Scientific knowledge is not really performed in a scientific manner because it relies on the ad-hoc, if not, chaotic ability to detect phenomena, a known stumbling block, hindered in part by capitalism of all things and we all know no one person has all the ideas, and we know that some test equipment is massively expensive and in the past didnt exist. So the low hanging fruit of being able to devise tests using our own senses and imagination, think Newton's gravity theory when hit on the head by an apple, or even theory's from ancient Greeks demonstrates that in practice, scientific discovery has been extremely unscientific despite the protestations of its adherents.

There's no magic or supernatural stuff here. It just means our scientific description of the world lacks the subjective. There is a fundamental epistemological limit to our ability to know how to combine the two. It doesn't mean the world itself has such a division. We just can't cognate how to reconcile the two.

I'm sure you are aware of the internet and search engines [8,9], if not perhaps films giving tantalizing inspiration and hope [10] of possibility's and insights into how to cognate and reconcile the current and future time beyond the realms of religions which constantly harp back to the past.

Not bad for an undergraduate of https://rb.gy/xhuwo9 if I might say so, whilst I might have spent time reading a dictionary, in order to create obedience to authority with the use of uncommon words from the vernacular of the commons, I'm not engaging in it here consciously, because the military have taught me some highly efficient means to get my message across which isn't compatible with those tenets from the law and order fraternity.

[1] https://rb.gy/xilvko

[2] https://rb.gy/grprda

[3] https://rb.gy/ahwngn

[4] https://rb.gy/j2dibr

[5] https://rb.gy/7rpejx

[6] https://rb.gy/vwgr1o

[7] https://rb.gy/yhxhlm

[8] https://rb.gy/s9wdn6

[9] https://rb.gy/5kte4d

[10]https://rb.gy/hzmop7

mannykannot3• 3 years ago

It just means our scientific description of the world lacks the subjective.

Unless we have an independent reason to think that this thought experiment applies only to scientific knowledge, then it applies equally to all fields of propositional knowledge.

We can - and do - speak about subjective experiences by assuming that other people have them, and they are somewhat like ours (while recognizing that there are differences: some people are blind, or color-blind, or have synesthesic responses to color), but we cannot communicate what it is like to have those experiences to other people. That this is so is readily reconciled with materialism: firstly, because we cannot experience what it is like for other people to experience color, we cannot develop a common vocabulary for communicating it; secondly, even if we had the vocabulary, our conscious mind does not have the ability to bring about the necessary changes in our brain through willpower alone.

hackinthebochs• 3 years ago

I still don't know what it is supposed to mean to know what it's like to see red. Having seen red, I have a memory of having been in a state of seeing red. Not having seen red I wouldn't have such a memory. But this has no consequence for physicalism. I can imagine myself in the situation of having seen red, e.g. imagining myself viewing a red apple. But I have aphantasia and so I'm certainly not remembering or imagining red in any meaningful sense. In no way is my memory of being in a state of seeing red presently constituted by phenomenal red. When we imagine red or some visual experience, we know the early visual areas of the brain involved in those sensory experiences are reactivated by feedback signals from the frontal cortex. Presumably seeing red gives me this ability which one lacks before seeing red. But this has no consequences for physicalism either. Besides, the article claims the issue isn't about being able to imagine red. So what is the nature of this supposed knowledge? The whole concept seems dubious.

atdixon2• 3 years ago

It might help to imagine a different world.

One in which Mary steps out of her room, sees a rose, and absolutely nothing new is added to her understandings.

She already had it all sorted out in her study. In many people’s understanding of “naturalism” that wouldn’t be any surprise.

But that’s not this world.

theresistor• 3 years ago

If she truly possesses all physical knowledge, then she knows exactly what every possible rose looks like from every possible angle, in every possible setting and lighting. She knows in excruciating detail, at the level of every individual atom, how the scent of the rose will reach her brain, and exactly what responses it will trigger.

And indeed had she that knowledge, nothing new would be added by seeing one in person.

The implausible part is presupposing any person could ever have a complete enough understanding of all physical knowledge to achieve that.

glitchc2• 3 years ago

Not sure I follow the original premise. If Mary knows everything there is to know in physics, then Mary knows about the wave theory of light and the colour spectrum. She may not have experienced the colour red but she is aware of the concept of the colour red.

Additionally, while Mary may only receive information in black and white, she perceives in full colour and can see the colours of her own skin and clothes.

The combination of the first and second facts means that Mary can conceive what it would be like to see the colour red before she ever sees it. The first time she sees green she will know that she has perceived some colour, even if she gets the label wrong and calls it red for instance.

tsimionescu9• 3 years ago

The point of the thought experiment is to ask if Mary would interpret the experience of seeing the specific color with her own eyes as a new experience. If yes, and given the premise that she knows everything that it is possible to know about the physics of color and the human brain, the conclusion is supposed to be that an experience is not a physical fact of the world.

I have written another comment on why I think this conclusion is wrong.

31337Logic5• 3 years ago

The conclusion is supposed to be that an experience is not a physical fact of the world.

I see what you're getting at and mostly agree (hence the Upvote!). But...

Whether a 1st person qualitative experience is a "physical fact of the world" depends on your level of description. In a sense, it's not an epistemically objective physical fact that I can share with others. However, it is just a brute ontological physical fact of the world that my mind experiences the color red (even if yours doesn't).

This is precisely where we need to clarify "facts of the world". We can't settle this chat until we introduce the notion of subjective vs objective, and epistemic vs ontological.

denton-scratch3• 3 years ago

I think the fallacy is to treat knowledge of redness as a "fact" about the world.

In general, when you learn a fact, you acquire information about the world that previously you lacked. But when you first experience redness, your knowledge of the world is exactly the same as it was when you were stll Monochrome Mary. The old Mary knew which things were red, like tomatoes; she was fully-informed about the nature of light and colour. The experience of redness has added nothing to her knowledge of tomatoes and their colour.

If that's correct, then familiarity with any qualia fails to be a kind of knowledge.

glitchc2• 3 years ago

But when you first experience redness, your knowledge of the world is exactly the same as it was when you were still Monochrome Mary.

That is still false though, because in that moment Mary realizes what redness looks like. She has mapped a sense experience to a concept, which is new knowledge. The author has to prove that this mapping exercise is indeed not new knowledge, as making a connection between two disparate events (acquisition of concept vs acquisition of experience) is considered net new knowledge based on the epistemical definition of knowledge.

tsimionescu9• 3 years ago

I don't think that's a substantial problem. We can reformulate the argument like this: assume that brain states correspond 1:1 to mind states. As such, for any qualia there would be a corresponding brain state. If Mary fully understands all details about light and the human mind and brain, she would be able to understand the brain state that would correspond to the qualia of her experiencing a red object. As such, she should be able to put her brain in that state.

If then she exits the room and actually looks at the color red, and if this experience is new to her, it follows that her brain is in a state that it has never been in before, which is a contradiction.

The original claim argues that this contradiction should be taken to mean that the first assumption is wrong - that brain states can't correspond 1:1 to mental states, or, equivalently, that there is no brain state that corresponds 1:1 to a qualia.

However, I believe that there is another premise which seems more obviously flawed, and which doesn't follow from this original one. That flawed assumption is that Mary could put her brain in any state she understands. I believe it's quite plausible that Mary could fully understand the brain state that corresponds to the qualia for seeing red, but still be unable to actually put her brain in that state.

In general, we don't seem to have any direct conscious control of our brain processes, just as much as we can't consciously control the function of our liver or pancreas.

31337Logic5• 3 years ago

Additionally, while Mary may only receive information in black and white, she perceives in full colour and can see the colours of her own skin and clothes.

No, she doesn't (and never has) perceived in full color. Her entire world has been modified (Truman Show style) to shield her from ALL color at ALL times.

okutanski• 3 years ago

There is computation done in Mary's system for which Mary doesn't have insight into, so what she doesn't know is the results of that computation she is bound to experience nonetheless.

Here is a short summary of the idea: https://leibgruber.blogspot.com/2022/08/the-missing-knowledg...

tsimionescu9• 3 years ago

This whole thought experiment is actually presenting what is quite possibly a limitation specific to human minds - no reason to extrapolate to all possible minds. That is, human minds seem to have two very distinct ways of altering their internal state. "Raw" sensory data gets stored in one way ("experiences"), while higher order data gets stored in another way ("memories"). That we can, to some extent at least, create memories of facts we learn from books, but we can't create experiences from facts we learn in this way can very well be an artifact of how our minds are fundamentally put together.

An analogy with a computer makes this quite obvious. If we imagine an AI running on a CPU similar to those we know, and given free reign to interact with everything including the contents of the computer as well, it's easy to see that an AI-Mary would not need to leave the room to experience the color red - it could simply alter its input channels/memory to generate the exact experience that its sensors would detect if they were pointed at a red object.

If however we alter the AI such that it can't access/modify its sensors directly, and it's sensors write data to a piece of memory that the AI also can't write to, then the AI-Mary will not be able to put itself in exactly the same state it would be in were its sensors pointed at a red object, and so would have some kind of a new experience when leaving the room.

But, this would not be some fundamental fact about subjective experience or qualia, it would simply be a limitation of the architecture.

skissane2• 3 years ago

This whole thought experiment is actually presenting what is quite possibly a limitation specific to human minds - no reason to extrapolate to all possible minds. That is, human minds seem to have two very distinct ways of altering their internal state.

How to define “mind”? If all human minds turn out to have a certain property, how do we decide whether that property is essential or accidental to “being a mind”? Obviously if the property is “being human”, it can’t be essential to the property of “being a mind” (unless someone wants to claim that only humans can have minds by definition-a claim very few would make). But, if the property is “having two very distinct ways of altering their internal state”, how do we know if that is just an accidental property that all human minds happen to have, but non-human minds might lack, or an essential property of being a mind, which all minds must have to be “a mind”?

tsimionescu9• 3 years ago

Sure - I'm not claiming to have settled the theory of mind!

I'm just pointing out that nothing in the argument about Mary, even if we accept that she would learn something new when leaving the room, proves that qualia must be non-physical or non-computational or anything like that.

You could find arguments that such a separation between qualia and physical facts is indeed necessary for any mind that could really exist in the world. But they would have to be other arguments - this one doesn't work.

somenameforme2• 3 years ago

Is it humans or computers with a limitation?

A single celled organism lacks any sensory perception and so, from its perspective, it has explored the depths of the universe without having to ever even move. With each step upwards in complexity, the entire perceivable domain becomes wider. That humans can experience a facsimile of something and the "reality" of something differently, would seem to imply that we have a more sophisticated input system than something that would equate the two different "inputs."

tsimionescu9• 3 years ago

A single celled organism lacks any sensory perception and so, from its perspective, it has explored the depths of the universe without having to ever even move.

Single celled organisms do have a kind of sensory perception and can react to changes in their environment. Even our own individual cells have this ability (and I'm not talking about neurons, I'm talking about every single cell in our body, or at least the vast majority).

In fact, some single celled organisms (or at least, colonies of them) have even been proven to be capable of certain computations - for example, "slime mould", which is a bacterial colony, can grow in a way which finds solutions to simple mazes.

That humans can experience a facsimile of something and the "reality" of something differently

That's not what I was talking about. I'm saying that we have no way to directly stimulate our sensory organs with with signals that mimic external stimulus, which would be quite trivial for an electronic brain. Also, I'm saying our memory of direct sensory experience (what I saw when I looked at a red thing) is separate from our memory of more conceptual subjects (what is the square root of 4, who conquered England from Normandy, what I ate this morning).

While it may turn out that this "architecture" is necessary for having consciousness/a mind, it doesn't seem a priori impossible to build an electronic mind that doesn't have these limitations/separations.

pgayed• 3 years ago

Does the experience of zero-gravity reveal information not otherwise available via its deduction from physical law?

somenameforme2• 3 years ago

Interesting example. There have been many [failed] efforts to try to recreate the overview effect [1] on Earth. One hypothesis for the reason that facsimiles (e.g. VR) of such don't drive the same experience as the real thing, is that zero-gravity is somehow a component of it.

[1] https://en.wikipedia.org/wiki/Overview_effect

mxkopy2• 3 years ago

This whole waste of breath is based on the obviously artificial distinctions between knowledge, experience, sensing, imagination and whatever other made up modes of thought this person comes up with.

"Mary knows every fact"

"Experiences are not facts"

"Therefore physicalism is false" I mean come on how did this get published ???

goatlover6• 3 years ago

There are facts about experiences. What is the experience of a fourth primary color? We're in a similar position to Mary before she leaves the room.

mxkopy2• 3 years ago

There's also the experience of knowing something, and I imagine it's like parentheses, exactly the same as knowing something. Again this whole know/experience distinction is presumptuous given our knowledge of neurobiology.

Case in point, I can guess that the experience of a fourth primary color is going to be close to one of another color. I know it's not going to be warm or anything (I'll guess that it looks kind of shimmery purple, why not, purple's mysterious). People do the same with drugs - it binds to XYZ receptor, releases ABC hormone; and just from some pharmokinetic principles you can guess fairly well how it's going to feel.

mannykannot3• 3 years ago

There are facts about experiences (such as the fact that some people have perfect pitch), and Mary can learn those facts from a book. It is a premise of this thought experiment, however, that you cannot learn things such as what it is like to see colors (or to have perfect pitch ourselves, for that matter) from books. The notion that this presents some sort of challenge to materialism comes from a) the way we use "to know" polysemously (at least in English), to refer both to having both factual information and memories of sensory input and emotions, and b) the misdirection of limiting what Mary studies to physics, as if this limitation on what you can learn from book studies was particular to the physical sciences. The argument is ultimately trivial, as its conclusion does not go beyond its tacit premise.

nopenotthat• 3 years ago

Like most arguments of this type it assumes the conclusion then acts like it’s terms don’t do that.

If Mary knows everything about red then she also knows what seeing it is like. If she doesn’t… then she doesn’t. They try to have it both ways by hand waving & hiding behind colloquial language but it still comes down to that in the end.

The thought experiment just reveals the writers own biases & limitations of thought rather than be revelatory in any way.

In fact this paper is often used by opponents of qualia as demonstrating why they are nonsensical & incoherent.

Got to say, I agree. Daniel Dennett has his flaws but his argument that this type of thought experiment is a category error & that qualia do not exist and are incompatible with what are basic facts we know about neuroscience should have ended this years ago.

31337Logic5• 3 years ago

If Mary knows everything about red then she also knows what seeing it is like.

Not necessarily. And if you assert it is true, then it can be true only in a limited sense.

Can you "know everything" about playing guitar if you've never actually done it yourself? I think you'll agree with me when I say the answer varies:

It's "Yes", if you mean "know everything" to stand for something like "know everything objective that can be passed along to another person without any loss whatever." (I'm thinking of things like how guitars are made, how they're tuned, how you play them, etc.)

But it's "No" if you mean "know everything" to also include your subjective first person experience of actually playing a real guitar (and why wouldn't you include that as part of your "know everything"?) If the subjective feeling is something to be known, then it ought to be included as part of your "know everything" list, right? (If not, why not?)

bajpaiharsh• 3 years ago

Our eyes are sensors! We collect data from them, if Mary doesn't know what Red looks like, hence she lacks this data. Hence, she doesn't know all the physical facts about the universe.

The initial point, of Mary, knowing all Physical facts hence doesn't seem to make sense, and therefore looks flawed!

wellpast• 3 years ago

But Mary does have all this data in her room - she knows every last interaction of wavelength to eyeball to neurons from her studies.

What doesn't Mary know in her room? You're proposing that you can codify that in some special (data-fied, 'factual') way that she couldn't possibly have access to in her room.

What is that codification, then? Be specific.

If you (we) can't do that, then aren't we just lunatics screaming and uttering and pointing at conscious experience with no ground?

mgkimsal• 3 years ago

Degree in philosophy, and ... used to read this sort of stuff for fun 30 years ago. Now... it's just like Mary seeing red; "ho-hum". I remember reading some Churchland years ago - I may have even read some of this back and forth exchange in some class years ago. I sense that this is more an issue of language than ideas, and people talking past each other. When it happens in the moment - face to face, perhaps - it's... at least interesting. You can at least try to determine if people are misusing language/ideas, and rectify it in the moment. You can't do that with papers like this. It feels like reading a Gish gallop.

henry700• 3 years ago

Well this text at least accomplishes a purpose... The purpose of showing us that not every philosopher is particularly smart

jmull• 3 years ago

I don't really understand the setup.

It seems to suggest that physicalism claims all things can be learned intellectually, in a box. It seems obvious to me that sensory experiences could be physical in nature yet also can only be learned experientially.

Is there really a debate that learning about color and seeing color are not the same things?

I don't know if the setup is unfair or the physicalism being referred to is silly. Either way this seems pointless to me.

ozy• 3 years ago

What we know by experience, by abstraction, or empirically, are three distinct modes of knowing. Experiences are directly known and always true. (Experiences might reference other potentially false things, and might be false indirectly.)

That resolves the whole Mary knowledge problem. Books cannot inject that kind of direct knowledge. Thus the claim "mary knows everything" is either false, or only true for a smaller domain.

One can think of analogies, like tamper resistant logs, or unique CPU states while doing static analysis vs running a program.

All in all, the non-physicalist conclusions are widely overdrawn. More over, for what it is worth, Jackson himself no longer thinks this argument is a good one.

31337Logic5• 3 years ago

In other words, "You can't derive 1st-person qualia from 3rd-person physics alone."

I've studied this for decades and it's a recurring theme not only with Jackson's "Mary" thought experiment, but with Nagel's "Bat", Searle's "Chinese Room", Leibniz's "Mill", etc.

The reason these arguments are often difficult to appreciate is because we struggle to put ourselves in the minds of other people, wondering how/if they perceive the world, but all the while we are using terms whose meanings and experiences we already understand intimately (e.g. red, rose, tomato... in the case of the Mary argument.)

The argument would have a bit more force if you imagined yourself landing on a strange new planet inhabited by Zorlichs. Zorlichs often drink Byzerp, which is a beverage made from Slayrne, Mucche, and Karlne. You're an expert molecular chemist. You've studied these ingredients for months and you now know all there is to know about Slayrne, Mucche, and Karlne. You know how they interact not only with each other but also with human biology (e.g. you'll know at least whether this beverage would harm you or not). Oh, you also happen to be a very picky person. Your entire life, you've never consumed any food or beverage that wasn't entirely bland. That means, you yourself have never had anything sweet, salty, bitter, or fizzy. So the question is: Would you know/learn something new to YOU upon first tasting Byzerp?

If we take "learn" to mean "acquire new experiences", then Mary certainly learns something new upon seeing red for the first time. Keep in mind that people can (and often do) learn something that is fleeting in time: you might have "taught" me how to bake brownies last year and, in that moment, I truly understood... that is too say, I was following along and comprehended every step along the way. But now it's 2023 and I've done nothing with that experience since. Indeed, I kinda forgot most of it. Is it now fair to say of me that I "know" how to make brownies?

"I learned" doesn't necessarily mean "I know".

And that flows both ways. Mary "knows" all there is to know about colour vision because she studied 3rd person objective facts about the world: light waves, retinas, brains, etc. But, if we stick with my definition of "learn" (i.e. "acquire new experiences") then Mary obviously hasn't learned what it is like to have a 1st-person red rose experience until she has that very experience.

That's not to say all learning must be a direct 1st person experience of the matter. I can learn all about the objective facts of skydiving without having experienced it firsthand. But I'll never know the subjective qualia of falling out of a plane towards the earth below until I actually do it.

Mary would have thought: "I don't know what it's like to see red." in the same way I currently think "I don't know what it's like to skydive". Yet both or worlds would be rocked (that is too say "learn something new") upon actually having the experience.

What Mary Didn't Know (1986) [pdf]

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