Friday, 4 July 2014

Colin McGinn's 'Can We Solve the Mind-Body Problem?' (1989)




We all have brains that are made of matter. Brains are made of neurons, biochemicals, etc.: flesh and blood. So how can “technicolor phenomenology arise from [this] soggy grey matter?” Why is the brain so different to our other organs? What makes it different? What is it about millions of neurons that gives rise to consciousness?

However, the main point of Colin McGinn’s paper is not how or why consciousness arises from brain-matter. It's the point that this link between body and mind may be – permanently – closed to us. He calls this “cognitive closure". And the property responsible for that cognitive closure he names P.

McGinn talks about our possible cognitive limitations.

Take, firstly, different species. They, presumably, are “capable of perceiving different properties of the world and no species can perceive every property things may instantiate”. So what’s true for other species will also be true for human beings. Think of bats and echo location. Dogs which that can hear sounds which we can’t even register. (In addition, dogs have far better senses of smell.) All these examples, however, display sensory - not cognitive - limitations and extensions.

So let’s get back to cognitive closure.

P is a real or actual property. It may even be concrete (e.g., part of the brain). This means that McGinn is not an irrealist about P. McGinn even describes P as possibly noumenal. As with Kant, noumena were permanently unknowable to us - by definition. Kant, of course, thought that the structures of the mind-brain would remain static for, well, the rest of time. (Though I don’t think that he ever explicitly stated this.)

It's the very nature of our mind-brain that renders P permanently closed off to us. However, despite the possibility that P is closed off to us, it could still be part - according to McGinn - of a respectable naturalistic scientific theory. Again, we shouldn't be irrealist or mysterious about P. Despite that, one can’t help but be mysterious about something that's said to be permanently closed off to us (as in Kant). Though does McGinn think in terms of permanent closure?

McGinn discusses a theory of closure which occurred to David Hume.

To Hume, our perceptual limitations determine our cognitive limitations. After all, he was a thoroughgoing empiricist. More exactly, according to Hume, because our “ideas” are always copies of sensory “impressions”, our concept-forming system relies on those impressions. Nothing can transcend the information provided by impressions and therefore our ideas.

(Kant believed that knowledge begins with impressions; though he also believed that knowledge isn't the end of our knowledge because of our innate a priori concepts which get to work on our impressions or on "phenomena". It's not surprising, then, that we could have asked Hume what he thought about our views on, say, atoms or distant galaxies.)

John Locke too believed “that our ideas of matter are quite sharply constrained by our perceptions”. In effect this meant to him that “the true science of matter is eternally beyond us”. Mind-free matter is “I know not what”. In concrete terms, this means that we can never know what solidity “ultimately is”. (Why does McGinn feel the need to use the word “ultimately"?) Again, this doesn't mean that Locke thought that nature “is itself inherently mysterious”. (I may ask how McGinn knows that Locke didn’t think this.) According to McGinn’s Locke, the mystery simply “comes from our own cognitive limitations, not from any objective eeriness in the world”.

McGinn explicitly states his position with regards to P. He resolutely shuns the supernatural. P must be natural. (How does he know this?) He goes on to say that "it must be in virtue of some natural property of the brain that organisms are conscious”. He concludes: “There just has to be some explanation for how brains subserve minds.” Again, why must this P be natural? Is this an example of McGinn’s faith in naturalism? And if it is, is it necessarily a bad thing to have a degree of faith in naturalism?

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