Body of Ideas

In an ongoing discussion over at Maverick Philosopher, one of the interlocutors has made the assertion, in defense of dualism, that the human mind must be more than the physical activity of the brain, because the brain is a finite physical system, and the mind of Man, allegedly, is infinite. To quote from the thread over at Dr. Vallicella’s place:

Because the human mind is not bounded, it cannot be physical.

Sounds good. We all have the feeling that we can accommodate any new concept that comes before us (though, on reflection, a peek at contemporary political discourse might be sufficient rebuttal), and adjust our behavior with limitless flexibility. But why do we think so? What makes us so sure?

I hate to psychologize, but one of the main reasons I think people cling to this view is that they would feel diminished, somehow, by embracing the alternative – although it seems to me that even if we are “merely” physical systems, we can still take comfort in the knowledge that we are physical systems of astronomical, astonishing complexity, with a conceptual repertoire that, even if it is not literally infinite, we may still confidently assume is inexhaustible in any practical sense.

But no self-respecting (and as I’ve just suggested, the dualist argument is motivated, I think, in large part by self-respect) dualist is going to frame the discussion in these terms, and I have no doubt that I have already given offense. So I’ll say no more about psychology.

How might it be shown that the mind of Man is capable of a literal infinitude of conceptual states? It was suggested in the current discussion that this can be seen from the fact that for any number x, we can imagine x+1 (suggesting that we can at the very least enter a number of conceptual states equal to aleph-null , the first transfinite cardinal, equal to the number of elements in the set of positive integers). But can we really do this? How will we make mental representations of numbers that are trillions of digits long? I believe this argument, which has an undeniable intuitive appeal, simply fails in practical application.

Similarly, it is sometimes argued that we can demonstrate the boundlessness of our conceptual space by considering the infinite extensibility of valid sentences. It is easy to propose conceptual structures that are seemingly extensible ad infinitum, such as “I think that he thinks that I think that he thinks that…“. But again, do we really imagine that we can explicitly represent such a sentence once it reaches a trillion, or for that matter even a thousand terms?

Perhaps a dualist might object that I am focusing too much on holding enormously large concepts in memory, whereas the idea is that we can accommodate a set of different concepts that is in principle infinite. Even if this were so, however, it is perfectly reasonable to assume that we would, once we reach some practical limit, simply clear out some old data to make room for the new. Certainly there is no way for the dualist to demonstrate that this isn’t the case. And if this is so, then in what way are we any more “infinite”, say, than a piece of clay that can assume an infinite number of shapes?

The human brain is the most complex object known. It also has the remarkable ability to reconfigure itself in dynamic response to its ever-changing informational context. It is an exquisitely designed intentional engine, and permits the human animal a behavioral and conceptual depth and flexibility that is unparallelled among living things. It also is the locus of the greatest mystery of all, consciousness. We have a great deal to learn about how all of this works, and it may well be that our minds themselves are simply inadequate to the task of understanding it all, as Colin McGinn has suggested. It may also be the case that dualism is correct, though I doubt it – it has always felt to me like a “God of the Gaps” approach to the explication of mental phenomena. But I have yet to see a convincing argument for dualism based on the alleged “infinitude” of Man (if you think you have one, please send it along). I think it is simply the atonishingly immense complexity of our cognitive apparatus – our evolutionary jackpot – along with the well-concealed fact that our consciousness cannot “see its edges” that is what deceives us into thinking we transcend physical limits.

Related content from Sphere