Q is for Qualia

GPs are used to QOFs and QUALYs, but qualia are far more vital! Qualia (singular ‘quale’) are the immediate individual conscious sensations that we experience, (such as ‘redness’, or pain) that we then put together and interpret as we mentally model the world. (Think of the old conundrum: how do I know that the redness I perceive when I look at a pillar box is the same as the redness you perceive?)

Logically if physical science can tell us all that can be known about the world then a person with colour-blindness must be able to know what it is to see red. We can construct this knowledge scientifically around a model of having the right sort of cones in the retina to perceive incident light with a wavelength of 650 nm, for example. Yet if this person — in possession of all available knowledge about redness — were to be cured of their colour blindness then they will learn something new that they did not know before: what it is to see red. An exhaustive scientific description of the perception of red objects does not contain an account of the qualia I experience as ‘redness’. This argument is a demonstration of something that is both profound and also obvious to all but the most extreme physicalist. Erwin Schrödinger made a similar point: ‘The scientific picture of the world around me is very deficient. It gives me a lot of factual information, puts all our experience in a magnificently consistent order, but is ghastly silent about all that is really near to our heart, that really matters to us. It cannot tell a word about the sensation of red and blue, bitter and sweet ... it knows nothing of beauty and ugly, good or bad … Science sometimes pretends to answer questions in these domains, but the answers are so silly that we are not inclined to take them seriously.’

We may know how neurons work but we still have no convincing explanation for consciousness itself. Consciousness is often described as an ‘emergent’ quality. In a complex system (let us again remember that the human brain is the most complex object in the universe, containing 10¹¹ neurons) qualities, indeed realities, ‘emerge’ that are more than the sum of their lower-order constituent parts. It would be unreasonable to insist that there is no such thing as ‘a table’ because science can only identify elemental particles arranged in a particular way within space and time. It would also be banal to say there was no symphony on a CD because all it contained was digital data.

There is something about consciousness that cannot be reduced down to physical processes in the material world. Although we can do a great job describing how neurons work, we still have no convincing physical explanation for consciousness itself. Materialist theories of mind omit the essential component of consciousness, namely that there is something that it feels like to be a particular conscious thing. Current reductionist efforts to tackle the mind–body problem cannot succeed. Qualia, and thus human self-awareness, cannot be contained within a purely physical account of the self. As Milton remarked ‘The mind is its own place’.

• © British Journal of General Practice 2014