Saturday, November 29, 2008

No Vital Spirits

Here’s an informative story from Patricia Smith Churchland’s Brainwise

"When William Harvey (1578-1657) began research on the heart, his guiding question was this: exactly where in the heart are the vital spirits” concocted? His question reflected the respectable, conventional, too-obvious-to-be-questioned wisdom of his time. According to conventional wisdom, blood was continuously and copiously made in the liver. The job of the heart was to make vital spirits (by virtue of which life existed) by mixing air from lungs with blood from the liver. The reason death followed the cessation of heartbeat was that the vital spirits ceased to be concocted.

In one of the great stories of science, Harvey ended up discovering something utterly different from what he sought. He discovered that the heart was actually a meaty pump, blood circulates around the body, and blood is continuously made, but not by the pint per minute and not in the liver at all. Shockingly, Harvey’s discoveries implied that almost certainly there were no vital spirits concocted in the heart—or anywhere else either. To come to see this, he had to doff the conceptual lenses of the framework of spirits—vital, animal, and natural—and don a completely different set of lenses." (256)

As I see it, we have long since passed a comparable point to Harvey’s gestalt shift with modern neuroscience and the persistent belief in a human soul. For centuries, we have labored away within a false set of presumptions about there being a special, independent, immaterial spirit that inhabits human bodies. And, not surprisingly, these common sense ideas about the existence of an immortal soul have been at the foundation of another set of myths in our religious beliefs. Our interests in God, heaven, the afterlife, eternal punishment, and human depravity and sin have been predicated on the notion that there is some essential part of us that survives the decay of the body in the grave and that goes on to some other ghostly existence. Without the existence of an eternal soul, the point about religious belief in God becomes largely moot. If we have substantial evidence to indicate that there is no afterlife for a human person, then for the most part, the mental and physical resources that we devote to God and related matters will be a waste of time and energy.

Our investigations into the human brain and nervous system have made it increasingly obvious that like Harvey’s initial presumption of vital spirits, our idea of some personal essence that exists separate from the brain is a backward holdover from model of the world that just doesn’t fit with the facts. When a brain gets damaged, the mental capacities that were produced by or depend upon that portion of our nervous tissues get compromised or destroyed. When we take psychoactive drugs that disrupt the chemical and electrical signals of our brains, the normal pattern of thoughts, reasoning, and phenomenal experience get disrupted. When the effects of those drugs wear off and the regular patterns of neural activity right themselves in our brains, our ideas and sensations return to normal. As neuroscience has pressed forward, we have become able to correlate with greater and greater precision the brain processes that are responsible for every aspect of our mental lives. It has become clear that even the most abstract, ethereal, and elusive experiences—the ones that gave us such conviction that there is something otherworldly and magical about human consciousness and existence—can be analyzed into simple, physical events in the brain.

Unlike Harvey’s situation, however, the belief in the human soul has lingered long after it has ceased to be a theoretically viable account of what we have found in our empirical investigations. Harvey, like Copernicus, Newton, and Einstein, was prepared to abandon his presumptions when they were not borne out by what he discovered. But a deep and pervasive affection in us for spirituality and for the notion of God keeps us from moving on and growing up. The lesson we can learn from Harvey’s case is to have the courage and the sense to realign our assumptions, even our most fundamental ones, in the light of new information.


Anonymous said...

great. science has proven there is no spirits. I guess that means there is nothing else but science as well? pretty bad logic professor...

Konrad Talmont-Kaminski said...

The thing I find fascinating is that, despite the evidence, we do maintain the tendency to think of ourselves in dualist terms. And, furthermore, that we manage to be somewhat rational, none-the-less, or at the very least manage not kill ourselves on the very next zebra crossing. Which reminds me of an old Tom Tomorrow cartoon:

Bror Erickson said...

Really? Someone went looking for the immaterial with a microscope? And we are supposed to listen to that idiot when based on the fact that he didn't find the immaterial soul with a microscope he told us they don't exist?
I went looking for an elephant at the mall and there weren't any there. Am I supposed to believe they don't exist?

Konrad Talmont-Kaminski said...

For something to meaningfully exist in 'our' universe it must impinge upon us in some non-random way. If it affects in such a way, it will, therefore, be detectable. Contrawise, if it is not detectable, it does not affect us and, therefore, is not meaningfully a part of our universe.

What holds in general is also true in particular circumstances. Thus, Harvey, and other scientists, went looking for vital spirits in the places that it had been commonly thought such spirits would be found. No influence of such spirits was detected there. So, quite rightly, Harvey decided that there were no vital spirits acting in those places.

To use the bad analogy from the previous post - if you go looking for an elephant in the mall and you don't find one, it's probably because there's no elephant in the mall. If you keep looking in other places and keep not running into that elephant you will soon reach the conclusion the elephant just isn't around in your neck of the woods. Which makes the great big gun in Bror's picture look pretty much superfluous, really.

Anonymous said...

hey I went looking for the concept of "freedom" but couldn't find it under a microscope. What did I do wrong? or was it science?

John Macossay said...

Anonymous, you have a good starting point -- now carry it out a bit farther and see where it goes. Freedom, justice, beauty, truth, etc, are abstract ideas. Is the soul also an abstract idea?