In a recent article published at Big Questions Online, Shermer says:
It would certainly seem so if you are reading these words online, but in fact you are not actually “seeing” the computer screen in front of you. What you see are photons of light bouncing off the screen (and generated by the internal electronics of the screen itself), which pass through the hole in the iris of your eye, through the liquid medium inside your eye, wending their way through the bipolar and ganglion cells to strike the rods and cones at the back of your retina ...His account of the act of seeing continues for several excruciatingly detailed paragraphs in which we are taken on a tour of the brain that we can easily imagine being narrated by Ben Stein and in which we expect at any minute to be asked to stay outside the rope and not to touch the exhibits.
This process proceeds until, says Shermer, we reach the neuron level, where particular neurons fire in particular circumstances. Shermer points out that several neuroscientists have even "found a single neuron that fires when the subject is shown a photograph of Bill Clinton and no one else!"
Unfortunately, this neuron frequently gives long boring policy speeches and attempts to mess around with other nearby female neurons and can create extremely embarrassing situations, so scientists have decided it's best not to study this one too closely.
But we finally arrive at this little gem:
The models generated by biochemical process in our brains constitute "reality." None of us can ever be completely sure that the world really is at it appears.Shermer calls this idea "belief-dependent realism," about which he promises to enlighten us in a future book, where, presumably, we will be treated to a series of letters, words, and sentences the perception of which will be routed through a long, involved neuroscientific process that will take us back to the neurons which his book will argue don't have any necessary connection with reality.
So one wonders why we should believe him.
This is the problem will all such accounts of experience that try to reduce conscious experiences to physiological processes: they undercut the very arguments used to support them, since the thoughts that produced the arguments and the thoughts that resulted from reading or hearing them are the very things the arguments have attempted to show aren't really real.
The way we derive a truth, in other words, is the truth itself. But if this is so, then isn't the truth "the way we derive a truth is the truth itself" only its own arbitrary derivation? And if so, how can we believe it's true?
Shermer, in fact, seems to be aware of this:
I claim that the only escape from this epistemological trap is science. Flawed as it may be because it is conducted by scientists who have their own set of beliefs determining their reality, science itself has a set of methods to bypass the cognitive biases that so cripple our grasp of the reality that really does exist out there."Is there a way around this epistemological trap?" he asks later. "There is. It's called science."
In other words, we must be skeptical of everything--except scientific skepticism. But why does science get a pass? Science is a cognitive process like any other, and must therefore suffer from the same solopsistic fate. Why are scientific thoughts not "models generated by biochemical processes" that "none of us can ever be completely sure" about just like the ones Shermer finds around him so ready at hand?
Once you believe in scientific reductionism, you can't believe it anymore. If you accept it, you must therefore reject it. Once you accept its presuppositions, you are forced in short order to abandon them. It is Chesterton's "thought that stops all thought," a universal intellectual solvent which, despite its pretensions to rationality, is the most anti-rational of all theories.
Anyone who decides to accept Shermer's argument passes under a sign that reads: "Abandon all truth, ye who enter here." But Shermer himself just averts his gaze whenever he encounters the admonition.
In fact, Shermer can't even get through is own article without having to assume the opposite of what he's just told us:
Even when two models appear to be equally supported by observations, over time we accumulate more precise observations that tell us which model more closely matches reality.Whoah. Hold on there. Weren't we just told that reality was only a model in our brain? How, then, can we use it to assess the models in our brain?
Chesterton had already refuted Shermer as long ago as 1908:
That is the ultimate evil against which all religious authority was aimed. It only appears at the end of decadent ages like our own: and already Mr. H. G. Wells has raised its ruinous banner; he has written a delicate piece of scepticism called "Doubts of the Instrument." [the early 20th century equivalent of Shermer's The Believing Brain] In this he questions the brain itself, and endeavours to remove all reality from all his own assertions, past, present, and to come. But it was against this remote ruin that all the military systems in religion were originally ranked and ruled. The creeds and the crusades, the hierarchies and the horrible persecutions were not organized, as is ignorantly said, for the suppression of reason ... For we can hear scepticism crashing through the old ring of authorities, and at the same moment we can see reason swaying upon her throne. In so far as religion is gone, reason is going. For they are both of the same primary and authoritative kind. They are both methods of proof which cannot themselves be proved. And in the act of destroying the idea of Divine authority we have largely destroyed the idea of that human authority by which we do a long-division sum. With a long and sustained tug we have attempted to pull the mitre off pontifical man; and his head has come off with it.Shermer takes note that he himself is more optimistic about the effects of drinking the reductionist Kool-Aid than is Stephen Hawking, who at least has the decency to keel over from the philosophical concoction and admit that scientific reductionism leads to an epistemological dilemma from which there is no escape: all facts are theory-laden, and there are cases where no observation can prove one model necessarily right or another wrong.
So what does Shermer propose as the way out of the trap he has set for himself? He has none. In the final analysis, we find him being slain in the Scientific Spirit:
[E]ven though there is no Archimedean point outside of our brains, I believe there is a real reality, and that we can come close to knowing it through the lens of science — despite the indelible imperfection of our brains, our models, and our theories.So this is where he ends up: swinging from the chandeliers at the scientistic version of a Holy Ghost Revival, crying, "I believe!" Which, of course, is very unbecoming for a scientist.