The Knowledge Argument: Can Consciousness Be Deduced to Purely Physical?
Are conscious experiences seeing the color red, the sensation of something cold, and such things that can be explained purely physically?
In philosophy, thought experiments are used by philosophers to evaluate the validity and coherence of their ideas and clarify their complex arguments through imaginary scenarios. Frank Jackson's The Knowledge Argument, or Mary's Room Argument by another name, is a thought experiment that serves the same purpose. It is an argument posed against physicalism- the doctrine that the world is entirely physical, including our consciousness- and essentially an imaginary scenario to display his argument against physicalism.
Jackson asks you to imagine a really smart scientist named Mary. She knows everything that there is to know about the physical and functional aspects of human vision, including the neurophysiological processes, the physics of light, and the entire scientific description of color perception. However, Mary spends her entire life in an all-black-and-white room. She is not color blind but has never seen colors because of that. So, even if she has never experienced what is it like to see a color, she knows all the physical facts about color vision. Then one day, she leaves the room and sees colors for the first time. Would Mary learn something new that she didn't before she left the room? If physicalism is true, then Mary wouldn't learn anything else since she already knew everything physical about human c0lor vision. But intuitively, wouldn't she learn something new that she didn't know before, something that cannot be reduced to purely physical, something that can be learned if only experienced directly? This, according to Jackson means that physicalism is wrong, and there are aspects of conscious experience that cannot be captured by physical. There must be subjective and phenomenal aspects of conscious experience.
This is also known as qualia. The what it's like aspect of the conscious experience and mental states, the way something feels uniquely and subjectively. Qualia are the raw, immediate, and personal aspects of consciousness that cannot be fully captured by objective and physical descriptions. For example, the feeling of pain, the smell of a rose, the sound of a musical note, the sensation of touching something soft, etc. These are all types of experiences that feel like something that cannot be captured the same way if only learned physically. So, Jackson's argument demonstrates the "gap" in our understanding of the relationship between the physical world and subjective consciousness that physicalism cannot explain.
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