Bernard Shaw's Remarkable Religion: A Faith That Fits the Facts

The Marriage of Science and Religion 217
required that this cockpit be situated so as to face backward. As you sat in
the vehicle you were facing the rear, yet the television view gave the impression
that you were seated normally, facing the front. You would operate
this craft just as you would an automobile with windows surrounding
you, yet you would not be looking at the landscape around you but rather
at images on the screens of cathode ray tubes. True, the objects surrounding
the vehicle “cause” the images, or rather light reflected off them and
into the cameras produces the images. But the glowing chemicals on the
screen are what you really see. Russell is saying that all of our images are
like that. The picture of our world provided by our senses is just that: a
picture, not the thing itself. What he means by “the causal theory of perception”
is that what happens in our brains is at the end of a sequence of
causally related events but that the cause and the effect are not the same.
Centuries ago people thought that when we saw things our eyes somehow
reached out to capture their appearance. Contemporary science
teaches that photons from the sun (or from artificial lighting) are reflected
off of objects in many directions, including into our eyes. The lenses of our
eyes bend the light in such a way that the only light to reach a given point
on the retina comes from a single direction. It is sometimes explained that
the lens projects an image onto the retina, but at this point the image does
not exist as such. Individual receptor cells convert the energy of the photons
into electrochemical energy that sends signals along individual nerve
fibers to the visual cortex. Only there, in a manner that remains totally
mysterious, are the many signals from the eyes brought together to form
the image that exists in our consciousness. So far as we know, all of the
nerves that bring signals from our senses to the brain are pretty much alike.
We have no idea why some signals result in the sensation of color and
others the sensation of sound. We certainly have no idea how all this neural
activity becomes part of a single, if ever-changing, awareness. Even the
sensations of bodily awareness appear to be actually situated in the brain.
This is the conclusion of the “phantom limb” phenomenon, in which amputees
will report having sensation in limbs that no longer exist. There is
much talk now about virtual reality: machines that can stimulate all of our
senses in such a way as to make us imagine that we are visiting imaginary
places and interacting with objects that exist only in a computer. Russell’s
thesis is that the only reality we know is such a virtual reality: a model of
the world surrounding us rather than the real thing. He was convinced that
the model was a reasonably accurate picture of the real world, but it was a
model nonetheless. Indeed, because of the way our brains switch signals