I spend a lot of my time in this blog arguing why I don't believe in God. Today I want to do something a little different. I want to talk, not about why I don't believe in God or gods, not about why some particular religion's belief in God is mistaken or contradictory... but about why I don't believe in the soul.
A lot of people who don't believe in God per se still believe in some sort of soul, some sort of metaphysical substance or animating spirit that inhabits people and other living things. And I think this is mistaken. I think it's every bit as mistaken an idea as God is.
And today, I want to talk about why. I want to talk about why everything that we think of as the soul -- consciousness, identity, character, free will -- is much more likely to be a product of our brains and our bodies and the physical world, than a metaphysical substance inhabiting our bodies but somehow separate and distinct from it.
Much, much, much more likely.
Here's the thing. I know that there are enormous unanswered questions about how the mind works, and indeed what it is. The questions of what consciousness is, how it's created, how it works... these are questions that we don't really have answers to yet. Ditto identity and selfhood. And we're not sure that free will even exists, much less how it works. The science of neuropsychology, and the scientific understanding of consciousness, are very much in their infancy. In fact, I would argue that "What is consciousness?" is one of the great scientific questions of our time.
But infant science or not, there are a few things we know about consciousness, identity, character, the ability to make decisions, etc.
And one of the things we know is that physical changes to the brain can and do result in changes to the consciousness, the identity, the character, the ability to make decisions. Changes caused by injury, illness, drugs and medicines, sleep deprivation, food deprivation, oxygen deprivation, etc., can and do result in changes to everything we think of as the "soul." Even some very small changes to the brain -- small doses of medicine or drugs, injuries or interventions to just a small area of the brain -- can result in some very drastic changes indeed.
In some cases, they can do so to the point of rendering a person's personality completely unrecognizable. Physical changes to the brain can make people unable to care about their own families. They can make people unable to make decisions. They can make smart people stupid, anxious people calm, happy people irritable, crazy people less crazy. They can render everything we know about a person, everything that makes that person who they are, totally null and void. Read Oliver Sacks, read V. S. Ramachandran, read any modern neurologist or neuropsychologist, and you'll see what I'm talking about. It's fucking freaky, actually, just how fragile are mind and self, consciousness and character.
And, of course, we have the rather drastic change to consciousness and character and coherent identity and the ability to make decisions, known as "death."
Simply cut off oxygen or blood flow to the brain for a relatively short time, and a person's consciousness and self and ability to take action in the world will not just change but vanish -- completely, and permanently. (Attempts to find solid evidence supporting life after death have been utterly unsuccessful: reports of it abound, but when carefully examined using good scientific methodology, they fall apart like a house of cards.)
Think about any other phenomenon in the world. When Physical Action A results in Effect B, we think of that as a physical phenomenon. Apply heat to water, and get steam; apply force to an object, and get motion; apply electricity to metals in certain ways, and get magnetism; apply vinegar to baking soda, and get gobs of rapidly expanding foam. These are physical events, every one. Only the most hard-line religious believers insist that God's hand is in every physical action that takes place everywhere in the universe. Most rational, reasonably- well- educated people understand that the physical world is governed by laws of physical cause and effect.
We have a phenomenon, or a set of phenomena: consciousness, selfhood and identity, character and personality, the ability to make decisions. There's a lot we don't know about these phenomena yet, but one of the few things we do know is that physical changes to a person's brain will result in changes to the phenomena. Small changes or drastic ones, depending on the stimulus.
Doesn't that look like a biological process?
Doesn't that look like phenomena that are governed by physical cause and effect?
Even though we don't fully understand them, don't these phenomena have all the hallmarks of a physical event, or function, or relationship?
I mean, even when we didn't know what gravity was (which, if I understand the science correctly, we still don't fully grasp), once we got the idea of it we understood that it was a physical phenomenon. Once we got the idea and began studying and observing it, we didn't try to explain it by invisible spirit- demons living inside objects and pulling towards each other. We could see that it was physical objects having an effect on other physical objects, and we understood that it was a physical force.
In other words, we don't need to completely understand a phenomenon to recognize it as a physical event, governed by laws of physical cause and effect.
And when you start looking at the "soul," you realize that that's exactly what it looks like, too.
Everything that we call the "soul" is affected by physical events in our bodies, and those events alter it, shape it, and eventually destroy it. Apply opiates to the brain, and get euphoria; apply a stroke to the brain, and get impairment in the ability to understand language; apply vigorous physical exercise to the brain, and get stress reduction; apply repeated blows to the brain, and get loss of memory and intelligence. Apply anesthesia to the brain, and create the temporary obliteration of consciousness. Remove blood or oxygen to the brain, and create its permanent obliteration. It looks exactly like a physical, biological process: a poorly understood one as of yet, but a biological process nonetheless.
And there's no reason to believe otherwise. The theory that the soul is some sort of metaphysical entity or substance has no solid evidence to back it up. Just as with life after death, attempts to find evidence for a spirit or soul have consistently withered and died when exposed to the searing light and heat of the scientific method. And there's never been any good explanation of how, exactly, the metaphysical soul is supposed to influence and interact with the brain and the body.
Not to mention why it can be so drastically altered when the body alters.
Is there energy inhabiting our brain and our body? Yes, of course. There are electrical impulses running through our brains and up and down our nerves; there are chemical signals being transmitted through our muscles and guts; we consume food energy and radiate heat.
But is there some sort of non-physical energy inhabiting our brain and our body? Is there some sort of non-physical energy generating our consciousness, our personality, our coherent identity, our ability to make decisions?
There's no reason to think so.
We have an enormous amount yet to learn about self and will, consciousness and character. But everything we know about them points to them being physical phenomena. And the more we learn about them, the more true that becomes.
Other posts in this series:
"A Relationship Between Physical Things": Yet Another Rant On What Consciousness And Selfhood Might Be
A Lattice of Coincidence: Metaphysics, the Paranormal, and My Answer to Layne
How I Became an Atheist, Why I Became an Atheist: Part 3