Wednesday, July 24, 2024

Knowing what it's like to see green

You know what it’s like to see green. Close your eyes. Do you still know what it’s like to see green?

I think so.

Maybe you got lucky and saw some green patches while closing your eyes. But I am not assuming that happened. Even if you saw no green patches, you knew what it is like to see green.

Philosophers who are really taken with qualia sometimes say that:

  1. Our knowledge of what it is like to see green could only be conferred on me by having an experience of green.

But if I have the knowledge of what it is like to see green when I am not experiencing green, then that can’t be right. For whatever state I am in when not experiencing green but knowing what it’s like to see green is a state that God could gift me with without ever giving me an experience of green. (One might worry that then it wouldn’t be knowledge, but something like true belief. But God could testify to the accuracy of my state, and that would make it knowledge.)

Perhaps, however, we can say this. When your eyes are closed and you see no green patches, you know what it’s like to see green in virtue of having the ability to visualize green, an ability that generates experiences of green. If so, we might weaken (1) to:

  1. Our knowledge of what it is like to see green could only be conferred on me by having an experience of green or an ability to generate such an experience at will by visual imagination.

We still have a conceptual connection between knowledge of the qualia and experience of the qualia then.

But I think (2) is still questionable. First, it seems to equivocate on “knowledge”. Knowledge grounded in abilities seems to be knowledge-how, and that’s not what the advocates of qualia are talking about.

Second, suppose you’ve grown up never seeing green. And then God gives you an ability to generate an experience of green at will by visual imagination: if you “squint your imagination” thus-and-so, you will see a green patch. But you’ve never so squinted yet. It seems odd to say you know what it’s like to see green.

Third, our powers of visual imagination vary significantly. Surely I know what it’s like to see paradigm instances of green, say the green of a lawn in an area what water is plentiful. If I try to imagine a green patch, if I get lucky, my mind’s eye presents to me a patch of something dim, muddy and greenish, or maybe a lime green flash. I can’t imagine a paradigm instance of green. And yet surely, I know what it’s like to see paradigm instances of green. It seems implausible to think that when my eyes are closed my knowledge of what it’s like to see green (and even paradigm green) is grounded in my ability to visualize these dim non-paradigm instances.

It seems to me that what the qualia fanatic should say is that:

  1. We only know what it’s like to see green when we are experiencing green.

But I think that weakens arguments from qualia against materialism because (3) is more than a little counterintuitive.

5 comments:

The Shadow said...

And then there's those of us who are aphantasic, and can't imagine green at all. I'm still quite confident that I know what it is to experience green, even though I can't imagine or remember it as green.

Alexander R Pruss said...

Good point!

Spesifik Çıkarımlar said...
This comment has been removed by the author.
Spesifik Çıkarımlar said...

Pruss, perhaps I could argue that 1 is still true. Two things can be said:
1) Knowing what green is like by experiencing it is quite different from knowing it by imagining it. 2) Imagining what green is like when I close my eyes (for which I must have had a past experience of green) is the same as experiencing green. These two are diametrically opposed. I think what I said in 2 is more correct. Imagining green is the same as experiencing green. So the qualia in definition 1 is still true. So the 1 you are trying to revise cannot be called false.
The second thing I said is very similar to your 3rd definition, but they are not the same, and I think the identity between imagining and experiencing green is possible with the current 1st definition. So there is no need to revise it.

Norm said...

I am suspicious of the use of the word "conferred". I think recognising the concept of " being relatively potential" and "being relatively actual" could help here. It's a matter of that knowledge existing in us in different states of potentia at different times. There's a sense in which we do have knowledge of green prior to experience or to put it more technically we have that knowledge in a specific state of potentia, but it isn't the state that most Philosophers refer to when they use the term "knowledge". Their use of the term knowledge, refers to something ( a propositional attitude?) that bequeath us a state in which we can manipulate that qualitative aspect of greenness "at will", bring it to mind etc, or even for people who suffer from aphantasia, the bare minimum ability to recognise green when experienced.
Notice that I mention that the knowledge is what gives us the abilities and can't be identified with the abilities themselves.

Once you experience green, you actually have knowledge of green, it is actual relative to your prior state but it is in potential relative to the state you are in when you actually imagine green or have an experience of green again.

It's hard for me as well to keep track of the potential states I admit. I think Dr Feser could perhaps articulate it much better. And he does accept the knowledge argument for qualia , this can be confirmed by his latest book on the soul as well. Perhaps an exchange on this would be beneficial to the scholastic philosophical community