For discussion on emergence, reality, objectivity, etc:
64 thoughts on “Purple Doesn’t Exist?”
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The Skeptical Zone
"I beseech you, in the bowels of Christ, think it possible that you may be mistaken."
Just to point out — as I would guess you all know — the Muller-Lyer illusion does not ‘trick’ people who have not grown up in rectilinear architecture.
I suspect that we are just now discovering that there’s far more neuroplasticity than previous generations could have suspected. Sterelny argues that increased neuroplasticity was a target of selection in hominid evolution. That seems quite correct to me as a hypothesis, though I do wonder how we could test neuroplasticity in chimps and humans.
The fact that any of the great apes have sufficient neuroplasticity to acquire a rudimentary language suggests that increased neuroplasticity relative to other primates is a general trait of all hominoids, perhaps selected for in correlation with tool-use. However, great apes do not deviate from the encephalization pattern of primates generally, and human beings do. (According to the data that Terry Deacon gives in The Symbolic Species, an ape with a 1200 cc brain would weigh about 2200 lbs.)
In her Brain blog posts, she positions herself as building on the ecological color approach of Evan Thompson as well.
Yes, that is my understanding of representationalism: the color is a represented property of objects, with the property itself being understood by applying science to study the objects and the perceptual systems of normal organisms. The exact property can vary by organism; for color it often is something to do with light (any wavelength) reflectance.
Strong representationalists would further say that qualia are nothing more than that representation plus something to make the it conscious (for Tye, that extra something is explainable via global workspace theory).
On the other hand, weak representationalists think a further, intrinsic and non-representational property is needed to understand qualia. For Block these are biological brain properties which we can only study via correlations but cannot further explain (currently?). For panpsychists, these further properties are non-physical (at least in light of current physics).
One problem with all of this is that the representational part depends on defining a “normal” observer, which many think impossible. As well, specific issues with color exist , eg color metamers which show that several completely different reflectances can be perceived as the same color.
So I like her idea that color is a emergent property of the process of color perception involving the individual organism and the environment, rather than just the environment as represented by a normal observer.
But now I wonder where the phenomenal experience fits in. The flavors of representationalism put it in the brain. Where is it for her theory? I’d be uncomfortable with any explanation that phenomenal consciousness is even partly outside the brain. I did not see her getting at this in the blog posts; I suppose it might be covered by the book.
I hope her approach to phenomenal consciousness isn’t a version of the sensorimotor ideas of Noe and some of the other radical enactivists.
There are lots of dichromatic people, and a few who are dichromats in one eye and trichromats in the other. There are people with few cones, and an occasional person with a brain lesion that eliminates not only color vision, but also the memory of color.
I’m surprised that philosophers would write about perception without referencing anomolous perception.
BruceS,
Bruce, where did you find this strong representationalist/weak representationalist categorization? Thanks.
I’m a bit color-blind and I’ve heard that kids with a color-blind parent are likely to have significantly better than average color vision. (Can y’all confirm this?) Anyhow, I make a point not to disagree with my (biological) daughter about colors.
petrushka,
Sure, but a human dichromat won’t have the same spectral response as a cat. Even human dichromats will differ from each other in terms of color perception depending on the cone type that is missing or defective.
They do reference anomalous perception, and quite often.
One of the cool things about this vid, IMO, is that it calls into question an age-old (at least going back to the late 19th Century) principle in philosophy, something used as an example in any number of text books. Viz.,
If X is purple (although red is the usual example), X is colored.
This was thought to be not only true, but necessarily true. It didn’t require induction: in fact no empirical premises need have been involved in somebody knowing it. A blind person might know it as well as a sighted one. It was, to some (those with a Kantian bent), a synthetic apriori proposition.
But now, depending on what is meant by “color” it just might be false. I.e., if colors are identical to particular wave-lengths of light, something might be purple and yet not colored.
Coolio.
walto,
I think there’s a deep lesson there for us Brandomians who like to appeal to “if X is red, then it is colored” as a textbook example of material inference.
Kantian Naturalist,
It was used by Moore, C.I. Lewis and others (I think even Keynes) as an example of a stronger entailment than material implication, too. A necessary connection.
Lycan in SEP for example. Also in in Crane’s Elements of Mind.
Tye words it differently (scroll to near the bottom or search for weak). He talks about weak only requiring that phenomenal content supervene on representation. This has the advantage of making strong a subset of weak, I think, but for weak to be different from strong, weak must also allow for non-representational properties. Or, at least, that is how I understand the implications of his definition.
Thanks.
Reading Lycan more carefully, I see he is saying the same as Tye. Weak = representation necessary for phenomenal content; strong = necessary and sufficient.
Purple Doesn’t Exist
If this means that Barney the dinosaur never existed, I will believe anything.
It is unlikely evolution could or would create colours for us to observe in our heads,
In fact evolutiuonism must teach this was done for us long before the primate stage.
otherwise different lines of primates would of evolved different results in how colourt is used by the mind.
Who is looking at the colours that are organized in our head?
it could only be that we are. So we are using a machine to colour the world whether its accurate or not.
Yes we can be tricked because we observe the machines reading and not the real natural world.
I say since we can visualize colour , with our eyes closed by just using our memory, then thats all the machine we look at. We simply observe a memory of colour alongside the coloured objects. Its simple looking at it this way.
a soul watching the world by watching our memoryt system.