by Julia Peavey
The Knowledge Argument, also known as Mary’s Room, is a famous thought experiment developed by Australian philosopher Frank Jackson in the 1980s. For those unfamiliar with it, it goes something like this: Mary is a brilliant scientist who specializes in the neurophysiology of vision. She knows everything about how color works; its wavelengths, its patterns, its pathway into the eye, its neurological effects, all of its properties. But she lives in a black and white room, she was born there, only able to observe the outside world on a black and white monitor. The question is, when Mary steps outside of her room for the first time, will she learn something new about color? Jackson argues yes: subjective, qualitative perception of true color - the feeling of seeing a red apple or a blue sky - is information Mary never would have encountered before. Therefore her previous knowledge, considered physical knowledge, would be incomplete.
Mary’s Room is, in fact, a leading argument against physicalism, the doctrine that all of reality is physical, that all mental phenomena are a consequence of the physical. When Mary learns something new upon seeing color for the first time, Jackson claims it shows that qualia (moments of subjective, conscious experience) exist as properties.
To place this concept in a less abstract setting, take two everyday people: we’ll call one Gina and one Tom. Gina is enamored with the idea of love - she’s read countless poetry collections, watches a romance movie every weekend, has interviewed happily married couples about their experiences. But she herself has never been in love. On the other hand, Tom is a military historian. He knows the detailed progressions of major conflicts, plays video game simulations of battle, has studied the memoirs of soldiers. But he is not a veteran, and has never actually fought in war. Reading, and watching, and hearing second-hand accounts all constitutes physical knowledge. But the feeling of falling in love, the feeling of fighting in war: that’s qualia. That’s what, according to Jackson, Gina and Tom respectively do not know.
There's actually an important neurological mechanism implying that people who experience qualia are different from those who gain physical knowledge about the same subject.
Neuroplasticity, the idea that our brains are subject to change, isn’t a recent discovery but has only been popularized in the last decade or so. It describes the idea that our brain adapts, it's moldable, it's, well, plastic. To put it simply, the pathways, the networks, and the patterns of our neural connections have the capacity to be reorganized and altered by stimuli. Structural neuroplasticity is, in part, facilitated by learning and experiences and memory. Our brain evolves with new pieces of information it receives through the strengthening of some synaptic connections and the pruning of others, as well as the occasional growth of new neurons. Theoretically, the connections induced by the immaterial, private, and subjective mental states of qualia are different from those created by processing physical information.
With that considered, the Knowledge Argument is so fascinating and crucial to learn about because it expands far beyond color vision. It suggests the existence of a whole universe of nonphysical properties and knowledge only discoverable through conscious experience. The pain someone else feels, the way they see the world; even if we map out someone’s brain down to the last neuron or measure the activity of their sensory receptors on a molecular level, the subjective level of their reality may still be out of reach. It’s tempting to speculate when it comes to the causes of such a persisting gap in learning; perhaps it all originates in the weakness of language and human communication, which doesn’t entail perfect, universally relatable descriptions and never has.
But the concept of Mary’s Room is still just that - a concept. Philosophy at its root. It has been argued that the experiment itself is faulty, as Mary's grasp on all existing knowledge of color would allow her to already have effectively pictured it. Some critics have also come to the conclusion that Mary couldn't have access to all physical knowledge inside her room, thus she has an incomplete understanding long before she steps outside. Frank Jackson even turned against his own creation later in his life, deciding that when Mary first sees color it constitutes a measurable event in the brain, not unknowable qualia beyond the grasp of physical explanation. A primary cause of the idea’s controversy as a whole stems from the understanding that we can’t test it empirically. That’s where, in the coming future, artificial intelligence may enter the conversation. AI systems, just like Mary in her black and white room, can have access to what most consider to be all existing physical knowledge. But if we focus on the moment of exiting the room, a theoretical AI system won’t learn anything new while, by idealistic definitions, a human will. The question is, at what point will artificial intelligence be able to obtain subjective feeling? At what point will it become as conscious as Mary? Can we even recreate consciousness if there’s parts of it permanently beyond our comprehension?
All in all, unless we one day measure the fine line between being in Mary’s room and stepping outside, Frank Jackson’s theory is simply a reflection - that of the ongoing quest to understand our own consciousness, to discover if we’re more than the sum of our parts. For now, there’s still an abstract sense of mystery about the way we perceive the world and what appears to be a limit to what we can know about what we cannot experience. The thought of Mary discovering something new is innately optimistic, but so is the thought of the new language, new philosophy, and new science which might one day grant us with more empathy. There’s no guarantee as to what we may discover or theorize next when it comes to the sweeping discussion of what knowledge is, but at the very least it will be something interesting to consider and debate.