At some point in our evolutionary history, pre-humans made an important leap in cognitive ability. We moved from first order contemplation to second order. That is, we went from thinking to thinking about thinking. Before this leap, we were not very much different than most of the animals we’re familiar with — dogs, cats, horses. We know they can think, and they are often very good at solving problems, but it’s pretty obvious that they don’t have the ability to think about the way they solve problems.
My cat gets upset with me because I don’t change his water until he drinks what he has. He prefers fresh cold water out of the refrigerator to water that’s been in his bowl for a day or two. Several months ago, he took a good look at a glass of water I had set on the coffee table. He recognized it as water, but found that he couldn’t get at it because his head is too big. Within a few minutes, he’d figured out that tipping the glass over put a nice puddle of fresh water on the ground that he could lick up at his leisure. As a result, I now have to either finish my water completely within a few minutes, or drink from a sealable bottle.
In my cat’s brain, there are objects and actions. He recognizes water when he sees it. He knows there is water in the sink, in the toilet, in his bowl, and in my glass. He experiences desire for water, and acts upon it, by walking to his bowl or searching out a glass I’ve left unattended. That’s pretty much the extent of it though. He never spends time thinking about how or why he craves water, or how or why he goes about getting it. He just thinks and acts.
Pre-humans were like this at one time. Then we made the leap. Unfortunately, when we made the leap, the scientific method, philosophy, logic, and empiricism were tens of thousands of years away. We were the only animal that had ever been able to think in this new way, and natural selection didn’t provide us with a user’s manual for our new ability.
In all of our experience as first order thinkers, we had only known objects and actions. We couldn’t think about “two” or “forever” or “greed.” We knew “gorilla” and “run.” We saw problems, and we solved them, but we didn’t think about how or why we solved them. We just acted on our thoughts without thinking about them.
Then, when we made the leap, we suddenly realized that there was a lot more to existence than what we had known before. We looked at other people and thought about them thinking, and thought about ourselves thinking, and noticed that even though other people were…. people… they weren’t us. Each person, in fact, was unique. They were recognizable not only by their face and body, but by the way they think. We could predict how other humans would act based not only on some vague notion of how all humans act, but because of how each specific human had acted in the past. Because of our newfound ability to think about thinking, we asked… why?
Our caveman brains struggled for an answer. Clearly, humans are something completely different from gorillas or tigers or running. Each human is unique, yet all humans are the same. This was a huge puzzle, and we simply did not have the philosophical framework in place to find the answer. Instead, we guessed what we were most accustomed to — “human-ness” is a thing. An object.
If human-ness is an object, what kind of object is it? We can’t see it, or taste it, or hear it, yet every human has it. When a human dies, he is not a human anymore. The human-ness has left him. So man searched for the thing that makes humans humans, and after doing as much research as cavemen could do, he came to the only conclusion possible — Human-ness is something invisible that lives in the bodies of humans, and escapes the body upon death.
And that is where we stand today. We have created layers of intricacy, complexity, and philosophical pretzel twisting, but at its core, the concept of a soul is the same today as it has always been. A soul is what makes us human, and it is an existing “thing” in the universe. When we discovered the scientific method and empiricism, it soon became obvious that the soul is not measurable in the ordinary way, so we invented another kind of object — a “supernatural object” — which is defined as not being measurable in the ordinary way.
Apologists have written voluminous defences of the ontological validity of the supernatural, but they have never crossed the simple hurdle of creating a universe of discourse. They have never been able to say what the supernatural is without borrowing or comparing with the natural. The answer is shockingly simple, of course. The “soul” as a “thing” is simply a category error. “Soul” is a fancy word for “human-ness,” and human-ness is a concept, not a thing.