Imagine this headline and lead in:
LEFT BRAIN IS A PATHOLOGICAL LIAR:
EVERYTHING YOU BELIEVE IS MADE UP
“The world as we know it was exposed today as being nothing less than a tissue of fabrications, lies and distortions perpetrated on the human animal by his left brain....”
The fictional headline and story lead-in are made up, but the facts supporting it are not. The following is from Stephen Pinker’s The Blank Slate, page 43:
“One of the most dramatic demonstrations of the illusion of the unified self comes from the neuroscientists Michael Gazzaniga and Roger Sperry, who showed that when surgeons cut the corpus callosum joining the cerebral hemispheres, they literally cut the self in two, and each hemisphere can exercise free will without the other one’s advice or consent. Even more disconcertingly, the left hemisphere constantly weaves a coherent but false account of the behavior chosen without its knowledge by the right. For example, if an experimenter flashes the command ‘WALK’ to the right hemisphere (by keeping it in the part of the visual field that only the right hemisphere can see), the person will comply with the request and begin to walk out of the room. But when the person (specifically the left hemisphere) is asked why he just got up, he will say, ‘To get a Coke’—rather than ‘I don’t really know’ or ‘The urge just came over me’ or ‘You’ve been testing me for years since I had the surgery, and sometimes you get me to do things but I don’t know exactly what you asked me to do....’
“The spooky part is that we have no reason to think that the baloney-generator in the patient’s left hemisphere is behaving any differently from ours as we make sense of the inclinations emanating from the rest of our brains. The conscious mind—the self or soul—is a spin doctor, not the commander in chief.”
That’s right—the left hand doesn’t know what the right hand is doing, and we lie to ourselves and each other all the time and don’t even know that we do.
As I read the above, I begin to get the picture that all our wonderful human ideas about reality are just handy rationalizations the brain makes up for us so that we can walk, talk and chew gum at the same time. Long ago I began to understand that the idea of a hypothetical superbeing (god) who created an afterlife, etcetera, is just the conscious manifestation of our body’s evolutionary drive to survive, a reason made up for our finding ourselves walking around in these atomic bodies and talking with other members of the troop of chimps we discovered ourselves among when consciousness first evolved.
By the way, the reason a surgeon would cut the corpus callosom in half is that some people suffer from seizures so severe, prolonged and frequent that medication can do nothing for them. Their only relief comes with a surgery that separates the left brain from the right by cutting the corpus callosum.