Qualia's Contribution to Consciousness

Daniel C. Dennet challenges qualia, the idea that subjective experiences of consciousness cannot be explained by functional and objective descriptions. Using Frank Jackson’s (1982) thought experiment of Mary who hasn’t experienced colour, but knows all the physical aspects of colour, he says when she sees colour for the first time, her experience doesn’t reveal anything new. He proposes the idea that qualia are not fundamental features of consciousness and are epiphenomenal, (a secondary phenomenon accompanying another and the result of it) as byproducts of the brain processes. I disagree with Dennet as I think qualia are significant in understanding consciousness. Qualia cannot be fully understood through other’s objective opinions alone as everyone’s experience of a new encounter differs. I will touch on Mark Bradley’s “The Argument from Coincidence” (Bradley, M. 2011) where he states that epiphenomenalism is explanatorily deficient. As I agree with him that the argument about qualia being epiphenomenal leaves some affairs unexplainable and so, qualia must be causally efficacious. 

One of Dennett’s arguments posits that if qualia were essential to understanding consciousness, then Mary leaving the room would provide her with new knowledge, but he states that her experience adds no new knowledge. Since Mary knows everything about colour from the physical to the physiological properties, so when she experiences colour, she’s just experiencing something her brain was already set up to do, and not learning anything new. So Mary can learn everything she needs to know just from third-person descriptions and physical processes, and qualia is not a necessary aspect of consciousness. He mainly states the main premise of ‘she has all the physical information’. Continuing the example of Mary, they decide to trick her with a bright blue banana, but she can’t be tricked as she knows what physical impression any colour would make on her nervous system. 

My attempt to undermine this argument is that such a premise is false. She clearly does not have all the physical information, as I think that experiencing colour is a necessary form of information. How would you describe a colour to someone who has never seen colour without using other colours or objects of that colour? Say the colour green, you might describe it as the colour of grass or a mix of blue and yellow, or even down to the very wavelength of light that must hit an object for you to see green, or how you feel when you see it, but you wouldn’t know what green is until you actually see it. If she knew the physical properties of it, then she wouldn’t know the light wavelength unless she tested it. Furthermore, any third-person description of green would differ from person to person. Take colour-blind people as an example. Normal vision uses all three types of cone cells correctly, or trichromacy. People with deuteranomaly and protanomaly (red-green colour blindness) have difficulty with red and green, and sometimes blue and purple hues. And if in some hypothetical world where we are able to fix colour blindness, when someone who is colour blind sees colour for the first time, they would learn to distinguish between what they know and what everybody else knows. They would learn something new when they see colour in a trichromatic way. Who’s to say that Mary isn’t colour blind? She might very well be. But even if she wasn't, we don't know that everyone with trichromacy see’s the same colours the exact same way. Therefore, I think the premise that she has all the physical information, and that she doesn’t learn anything new is false. 

Another of Dennett’s arguments states that qualia are epiphenomenal. Where in this case means conscious experiences are byproducts of physical processes and do not have causal efficacy. Meaning that anything that we experience subjectively, is just a side effect of a physical process in the brain such as neurons firing. That they’re not two separate phenomena. Since qualia don’t provide any new information, he concludes that they are manifestations of brain activity rather than causally effective phenomena. His stance on epiphenomenal qualia aligns with physicalism, where all phenomena can be explained physically. When we experience something new, this physicalist approach states that they don’t have an impact on how our brains process information or make decisions, and that they don’t influence our behaviour in any meaningful way. 

I believe that qualia is important to understanding consciousness however. Dennett’s approach completely rules out the significant role that qualia plays in shaping behaviour, even as a child with the nurture side of nature vs nurture. If everything was just a physical process in the brain and qualia were really insignificant, and were devoid of any causal efficacy, they wouldn’t have an impact on behaviour and all humans would turn out quite like one another. Mark Bradley proposes “The Argument from Coincidence” (Bradley, M. 2011) where he states that ‘There are a series of correlations between physical properties and qualitative properties where epiphenomenalism cannot provide an explanation and therefore epiphenomenalism is explanatorily deficient’ (Bradley, M. 2011). Then illustrates this where x receives a stimulus, so there’s a physical property partially caused by said stimulus, and causes a behavioural physical property, but also the instantiation of a qualitative property e.g. pain. Which according to epiphenomenalism has no causal effects. Take the example of Mary. She receives a stimulus (seeing colour) which has a physical property (rods and cones process this), and a qualitative property (e.g. happiness). I bring into this example Chalmer’s ‘zombie’ argument (Chalmers, D. 1996). Identical beings with human beings, but not phenomenally conscious. If Mary were not phenomenally conscious, or if qualia were not important, she would feel nothing at all. She would be like a zombie. But instead, her perception of colour plays a role in her sensory inputs of a conscious experience. I further argue that qualia does in fact have causal efficacy with further evidence of PTSD. For example a soldier returning home from war after seeing so much terror, having a change in behaviour or a change in decision making. Their subjective experience of the war has a qualitative property and goes on to shape behaviour and how they view the world. Therefore qualia having causal efficacy. Another piece of evidence is introspection. We can reflect on thoughts, feelings, and sensations which provides first-hand evidence of qualia. The fact that we can do this suggests that they are more than epiphenomena and contribute to our consciousness. Furthermore, qualia helps us to adapt. For example, you burn your hand on a hot pan and experience pain. You now know not to touch a hot pan why? Because that subjective experience of pain helps you to make that decision, therefore being crucial to our consciousness and not epiphenomenal. 

I don’t think that my objection undermines the original argument as both arguments have their flaws. Dennett could reply to my argument by saying that she didn’t learn anything. Our brains already know how to see colour, they’re programmed to, through rods and cones, even if it isn’t the ‘right’ colours. But Mary just acquired a new skill. For example I can say ‘I can speak 47 languages’. Can I? No. But if I said ‘I have the ability to speak 47 languages’, then that’s a different story. Mary could always see colour, but after exiting the room, now she has the ability to see colour. In response to myself dismissing the premise, Dennett could respond by asking ‘Is experiencing something a physical property?’. However, I do think I raised some decent points in undermining his epiphenomenal qualia argument as we do adapt from our subjective experiences, especially pain, or even that we don’t reflect on our thoughts, because the majority of people do. 

Thus, I think that Dennet is wrong in saying that qualia do not have an impact on understanding consciousness and that it can’t just be explained through third-person descriptions. I think that saying that Mary had all the physical evidence wasn’t right as I think actually experiencing colour is a form of physical evidence and since everyone experiences colour differently, Mary could have a different experience seeing colour to everyone else. I also think that epiphenomenalism in this case is explanatorily deficient as there’s many cases where correlations between physical properties and qualitative properties cannot be explained. And that if qualia did not have an impact of consciousness, that they’re suggesting that we would all be like zombies, per Chalmer’s argument. Qualia possesses introspective and adaptive qualities, which are necessary and important to the human conscious mind.

Further Reading

• Bradley, M. 2011. The causal efficacy of qualia. Journal of Consciousness Studies, 18 (11-12), pp. 32-44.

• Chalmers, D. 1996. The Conscious Mind: In Search of a Fundamental Theory. Oxford: Oxford University Press.

• Dennett, D.C., 1991. Consciousness Explained. Little, Brown and Co. p. 398-401.