Sep 1, 2025 Art
The first philosophical problem young children often ponder — usually with no help from anyone — is whether their experience of colour is the same as yours. That is, when you both point to something we all call ‘red’, might they be seeing what you call blue? And how could anyone ever know, since we all get by while calling the same things ‘red’, even if we experience them differently?
Scientists can certainly give us an exceptionally good account of what red is — the interaction of wavelengths from a certain part of the electromagnetic spectrum with a human eyeball, optic nerve and brain. Most philosophers have learned not to argue with scientists about things like that. It’s the extra bit that philosophers worry about: the internal experience or ‘qualia’ of seeing red; the ‘red-y-ness’.
To understand what this means, an Australian, Frank Jackson, imagined a brilliant and very diligent scientist called Mary, who has sadly lived her whole life in a room where — as I understand it — the light is distorted so that she can see only black, white and shades of grey between. Even if Mary cuts herself peeling a grey ‘orange’, the light in the room would mean she’d bleed grey.
In this thought experiment, a now-elderly Mary has read everything there is to know about the electromagnetic spectrum, the eye, the optic nerve and the brain, and how they interact. Mary is so clever that she’s understood perfectly and never forgotten anything she has ever read. She’s also picked up all the links between the different scientific accounts she’s read. For the sake of the thought experiment, this isn’t limited to everything today’s scientists know about the electromagnetic spectrum, the eye, the optic nerve and the brain, but everything human beings could ever know.
Let’s add that Mary is also an expert in music and literature, understands dozens of languages and has listened to or read every composition and literary account about the colour red — not just those that have already been composed or written, but all that ever will be. After a lifetime of study, Mary has experienced and understood everything across science and the humanities that human beings will ever have to say about the colour red, except she has never seen it.
Yesterday, she escaped and saw red and other colours for the first time. (Just go with the idea that a lifetime in the black-and-white room hasn’t affected her visual, cognitive and connotative abilities.) The big question is this: When Mary finally saw red and other colours for the first time yesterday, did she learn anything?
If you think the answer is no, then you think ‘red-y-ness’ is something that could be understood purely intellectually through science, music, literature or a combination. If you agree with Jackson (and me) that the answer is yes, then this extra thing she learns — the ‘qualia’ of experiencing red — is the thing philosophers and young children wonder about being the same for everyone.
It seems to me that if Mary already knew perfectly well what it’s like to see red before she saw it, then that implies one person could explain to another what it’s like — in which case, we probably all do experience red the same. But if Mary did learn something new that couldn’t be understood any other way, then we’re stuck with our childhood problem. Is red the same for everyone, and how could we ever know?
We probably can’t, just as sighted people probably can’t ever know what it’s like to be born blind, and vice versa.
People who become blind sometimes report that they ‘see’ nothing, in a way that sounds similar to what a sighted person reports experiencing when they have their eyes closed. But for people who have always been blind, asking what they ‘see’ from their eyes is like asking a sighted person what they ‘see’ through their elbow, or smell through our ears, or — as American philosopher Thomas Nagel famously asked — what it’s like to be a bat.
Children are taught to understand bats as being able to ‘see’ through echolocation. They emit sound and can ‘see’ what’s ahead of them by how the sound bounces back at them — a biological version of the sonar systems humans developed for submarines.
Nagel’s point, though, is that the bat probably doesn’t ‘see’ the cave wall in front of it the way we would see it with our eyes with the help of a torch. Then again, maybe it does? Nagel asks how we could ever know what it’s like to be a bat using echolocation. And how could a bat know what it’s like to be a human using eyesight? It’s the same problem, broadened to a different kind of sense, as whether your red is my blue, and vice versa.
In fact, some blind people do seem to develop skills that are something like echolocation to get around. But we still face the problem that sighted and never-sighted people aren’t really able to properly communicate with each other what it is to ‘see’ — in general, or specific colours. For that matter, can a sighted person know what it’s like to read using Braille? When I see the word ‘Braille’, it has a certain quality to it on the page or screen that evokes a further visual-like qualia of what it means. It would be very surprising if this was the same experience that a blind person has in reading the word ‘Braille’ using Braille.
Or take seagulls and other birds, which we believe are able to sense air pressure and changing wind and weather ahead, better than humans can. They ride favourable wind currents and avoid turbulence better than aircraft and pilots. Perhaps sailor Peter Burling could tell us what that’s like — being able to sense that the wind 500 metres to port is fractionally more favourable for his wings than that 300 metres to starboard. But he may be unable to tell us how he knows it. Even if he could point to the patterns on the water, the clouds and their movement, that isn’t the same as understanding the feeling he gets when his mind processes all that information in an instant — whereas most of our minds can’t.
Why is this important? It may not be, except that there is a natural human urge to ponder at least the basic colour question from a young age. But if we accept that we all do experience the world differently, at least to some degree, we might be able to appreciate there are some things that I believe and understand that you do not — and probably cannot — and vice versa. And that might matter for how we decide we are best to get along with one another as we go about our different lives.
