Wednesday, March 2, 2016

Do I know what it's like to see red when I'm not looking at something red?

I've seen red. But as I am writing this sentence, I am not seeing red (my eyes are closed). So do I know what it's like to see red?

Let's try "no". Then the knowledge of what it's like to see red is really evanescent: it's only present when actually perceiving red. Moreover, it seems that what's relevant is not just the perceiving of red, but my attending to apparent perception of red. So it seems that I only know what it's like to see red when I attend to an apparent perception of red. But when I do attend to an apparent perception of red, then I surely know what it's like to see red. So I know what it's like to see red when and only when I attend to an apparent perception of red. This now makes me worry that "I know what it's like to see red" is just a more colloquial way of saying "I attend to an apparent perception of red". And if that's so, then the Mary argument for the nonphysicality of qualia is undermined. Furthermore, I think a lot of the intuitive plausibility of the argument comes from imagining oneself in Mary's pre-seeing-red stage, and imaging the kind of curiosity we'd have about what it's like to see red. But if this curiosity is a desire for knowledge that one doesn't have, and if I don't know what it's like to see red, then it's surprising that in Mary's position we'd have curiosity, but when my eyes are closed and I am not seeing red I have little curiosity about what it's like to see red, even though I don't have that knowledge. This suggests, in turn, that the curiosity that we would have in Mary's position isn't a desire for knowledge, but a desire for perception. So, all in all, the "no" answer seems harmful to the Mary argument.

What about "yes"? Intuitively that's the right answer. Surely people know what it's like to have perceptions that they aren't occurrently having. But now it's not clear what my knowledge of what it's like to see red consists in. Does it consist in the fact that even when I'm not looking at anything red, I can bring to mind a memory of seeing red? I'm not very good at it. I search my memory and find a memory of looking at a red object. For a split second, a flash of a red v-shaped piece of tape on a climbing wall shows up in my mind, before disappearing. Is my knowing what it's like to see red constituted by my possession of the skill of producing such evanescent memory images? Then it sounds like know-how rather than the kind of knowledge that's relevant to the Mary argument. And my skills in this direction are quite limited. I've seen very good approximations to circles: for instance, the clocks in the classrooms I teach. But when I bring such seeing-a-circle experiences back to memory, the images are far from being good approximations to circles--instead, I get foggy images of arcs that don't even meet up.

All in all, I am puzzled. I just can't put my finger on what it is that I have when I know what it's like to see red...


entirelyuseless said...

Do I know what "chair" means? Yes, because if I walk into a room I know which things are chairs.

Do I know what it is like to see red? Yes, because as I proceed to have additional experiences I know which experiences are experiences of seeing red.

That does not necessarily undermine the Mary argument, because it at least seems that when Mary first sees red, she doesn't have a way to be sure that she isn't seeing green instead.

I think it's possible that there is abstract knowledge that Mary might have, such that if she had it, she would in fact be able to identify her experience as seeing red on the first occurrence. I am not confident of that, but I think it might be the case, and if it is true, I think it would indeed undermine the Mary argument.

Alexander R Pruss said...

Mary might well have the ability to recognize red. Perhaps she has read that red makes people more excited than green, and when she sees red, she can recognize it by the excitement it causes. Or she could easily have an innate power to form the belief "I am seeing red" when she sees red.

Furthermore, Mary's lack of recognitional ability really shouldn't bother a physicalist. I know what the difference between water and heavy water is, even though I don't have the ability to tell them apart.

entirelyuseless said...

Your first argument is in fact roughly what I meant when I said it is possible that there is knowledge that could cause her to recognize what she sees as red. If that knowledge was so determinate that there is no reasonable chance of her failing to recognize that she is seeing red when she sees it, I would indeed say she knew in advance what it was like to see red.

I disagree with your second argument. Water and heavy water are not experiences, so you don't need to have the ability to tell them apart by looking at them. But the differences you attribute to them, would themselves be expressed in terms of things which you can tell apart (or they would be if you continued with a process of defining the difference in terms of yet more differences.)

On the other hand, in Mary's case, we are asking whether she knows "what it is like to see red." That is just an experience; if she cannot tell it apart from other experiences when she has it, she clearly does not know what that experience is like.

Alexander R Pruss said...

"if she cannot tell it apart from other experiences when she has it, she clearly does not know what that experience is like."

Here's an argument that some people (not so much me) are impressed by: There is a close color sequence ABC such that you can tell A from C, but can't tell A from B or B from C. In such a sequence all three colors correspond to distinct experiences. First, clearly A and C correspond to distinct experiences. But if A and B corresponded to the same experience, then you'd be able to tell B from C, since you can tell A from C. So A and B yield distinct experiences. (So do B and C.) Hence there are cases of distinct experiences, namely the ones connected with A and B, that we can't tell apart.

Heath White said...

I think you do know what it is like to see red, when you are not looking at red. But I don't think there will be anything helpful to say about what it is you know. The whole point of talking about qualia like this is that they are not susceptible to analysis: you either have the experience, or you don't. Chairs, etc. can be described; but not colors (usually). So there isn't going to be an answer to "what do I know, when I know what it is like to see red?"

Alexander R Pruss said...


Here's another way of getting at an issue here. Knowledge comes in occurrent and non-occurrent varieties ("dispositional" people say, but that confuses the issue; a disposition to know is not the same as dispositional knowledge).

Let's grant that I all the time non-occurrently know what it is like to see red.

But when is it that I occurrently know what it is like to see red?

Does that happen only when I am actually attending to seeing red?
Or also when attending to imagining red?
Or does it also happen at other times, times without either the experience or the imagination?

I am honestly having trouble identifying the particular occurrent mental state that counts as the occurrent knowing what it is like to see red, unless it just IS the attending to seeing/imagining red.

entirelyuseless said...

I am not impressed by the ABC argument. "I can tell these two things apart" is not something which is rigidly true or false, but can be more or less true depending on the case.

So here's an example. Suppose someone shows me two shades of green, one of which is lighter than the other, and asks which is lighter. Let's suppose he starts out with two obviously different shades. I will easily be able to tell him which one is lighter.

But then suppose he gives me progressively closer shades of green, but where one is always lighter than the other, but in smaller and smaller degrees. If you suppose that I will answer correctly 100% of the time up to a certain point, after which I will suddenly begin to answer randomly, you are mistaken. There will be shades so close together that I can answer correctly, but only 75% of the time. So I have an ability to tell them apart, but not a perfect ability.

From this the response to the ABC argument is obvious.

Alexander R Pruss said...

That's a good response. I think that once they get close enough, it might have the same phenomenology as blindsight. I don't know if that's relevant.

Mark Rogers said...

Hi Alex!
What do you think of this model?
Let's say we put Mary back in her room. Now we know Mary can no longer see red. She can remember red and thus her imagination is much improved but she can not see red by definition. Suppose we bring her out again. Now when she perceives red once again would we want to say "now she knows what it is like to see red" once more? I think, since she already knows what it like to see red, we should rather say "She is now attending to the perception of red". She only gets to "know what it is like to perceive red" one time and that was the time she first perceived red. So Mary knows what it is to perceive red but you do not because you have forgotten the first time you perceived red and you can not (unless you experience total red amnesia I suppose and re-have a first time experience of perceiving red) know what it is to experience red. So, no you do not know what it is to see red, you have forgotten, now you merely attend to the perception of red. But it is possible, as in Mary's case, to know what it is to see red.