He writes:
This form of metaphysics takes the position that the only things that exist are matter and mindless physical processes. But in a world of pure matter, how could you have subjective, conscious beings like us?The problem for materialist philosophers is that there's no plausible physical explanation for consciousness. For example, sensations like pain are caused by physical processes in the nervous system and brain, but the sensation itself is not physical. It's not something that can be observed or measured by anyone other than the person experiencing it. How do atomic particles like electrons zipping along neurons produce the sensation of pain or sound or color? What is the bridge between the physical stimulus and the non-physical sensation? No one knows.
To someone schooled in the great historical philosophical traditions — which have been largely dismissed following the adoption of post-modernism in the academy — this debate is immensely frustrating. In fact, much of the ongoing conversation about consciousness is self-evidently absurd.
"The scientific and philosophical consensus is that there is no non-physical soul or ego, or at least no evidence for that," writes philosopher David Chalmers. The New York Times backed him up, calling this a "succinct" summation of the status quo. Except that it's not.
First of all, there can be no scientific consensus or evidence about non-physical realities, because science is only concerned with physical realities. As for the "philosophical consensus," well, anyone who knows anything about philosophy knows that there has never been such a thing and never will be. And even if there were, it wouldn't mean anything, since philosophy is not a science; in science, an expert consensus does represent the state of the art of knowledge on a particular issue. In philosophy, it merely represents a fad.
Some materialists claim to solve the problem by asserting that the sensations just are the electrochemical stimuli, but not many philosophers are willing to agree that their experience of pain is nothing more than the firing of specific nerve fibers. Surely the agonizing sensation of pain is more than just atoms whizzing about. The sensation of sweet is something other than a chemical reaction in the brain. The sound of middle c is something other than the vibrations which elicit it.
The 18th century mathematician and philosopher Gottfried Leibniz argued that if an observer were miniaturized so that he could be inserted into a patient's brain he wouldn't see the brain light up red when the patient looked at a red object. We know today that all he'd see would be the flux of molecules coalescing and coming apart, so where does the red come from?
Gobry continues with a look at the work of philosopher Daniel Dennett:
Another argument on consciousness that enjoys a bit of consensus, especially lately, is that consciousness is an illusion. Our brain constructs models of the world around us and then tricks itself into believing that this is an expression of the world. The foremost proponent of this view is the philosopher Daniel Dennett.There's more from Gobry at the link. He's right that Dennett's view seems nonsensical. If consciousness is an illusion then the sensations we have of pain, sound, fragrance, and so on are also illusions. So, too, are our ideas and thoughts. If this is so, then almost our entire experience of the world is an illusion, including Dennett's idea that consciousness is an illusion. What's the point, Dennett might be asked, of writing a book full of ideas which, if true, are themselves illusions? Isn't the very act of trying to persuade someone of the truth of one's illusions a rather vain exercise?
But again, this view is literally nonsense. The concept of an illusion presupposes that there is a subjective consciousness experiencing the illusion.
This is a good example, unfortunately, of the silliness into which very intelligent people lapse when they're determined to efface any vestige of the "supernatural" from their metaphysics.