Long relegated to the realms of religion, myth, and superstition, the soul is actually our most useful concept for a scientific approach to what it means to be a person …

At the eye of the storm was Terri, a former bookkeeper who had been in a persistent vegetative state since suffering a cardiac arrest in 1990 which resulted in the loss of more than half of her brain tissue, leaving her with merely reflexive responses and no higher cognitive functions. Her husband Michael saw no reason to continue providing life support to her body. Her parents and brother, however, believed that Terri would not have wanted to violate the Catholic Church’s position on euthanasia.

“There’s a person in there”

One of my most lasting memories from the news coverage leading up to Terri Schiavo’s death on March 31st, 2005, was video footage of a protester crying out in genuine distress, “There’s a person in there!” This simple but compelling idea formed the crux of the debate over her life, and was echoed by her family, her caretakers, and the media.

On March 18th, CNN commentator Wolf Blitzer had summed up an interview with Terri’s brother Robert by saying “there’s a person in there, there’s a person who’s alive, and we shouldn’t take that life away.” Interestingly, Terri’s former nurse Patricia Tomko had used the same 5-word phrase 17 months earlier when arguing that Schiavo should be allowed to die: “It’s just a body; I don’t think there’s a person in there who can actually understand.” And in the wake of Schiavo’s death, Vatican spokesman Joaquin Navarro-Valls invoked her personhood when condemning the removal of her feeding tube as murder, asserting that her demise “was arbitrarily hastened because nourishing a person can never be considered employing exceptional means.”

This sense of a “person” residing “in there,” inside our bodies, inside our heads, is the essence of the concept of the soul. So what are we talking about when we assert that there is a “person” inside the head of a conscious human being, but not inside the head of a scarecrow or a doll or a statue?

Obviously, we’re not talking about mere reflexive reactions  —  the kind that make your leg twitch when the doctor taps your knee with a rubber hammer. Such responses are essentially no different from a car window’s response to our pressing the button to raise or lower it. An action creates an impulse through a series of wires (or a chain of nerves) and a physical reaction occurs on the other end. The car has no conscious experience of anything that’s going on. It lacks what we traditionally have called a soul.

Pointing to the Soul

What do we mean when we talk about a soul? Already, you may be thinking of centuries-old religious and philosophical arguments that make a clean definition of the soul seem practically impossible  —  is the soul immortal… does it pre-exist birth… is it reincarnated? But none of this is essential to the soul; rather, these are supposed qualities of the soul, so we must dispense with all these distractions first.

The soul is our conscious experience of the world. Whether we are awake, dreaming, or hallucinating, it is there. But when we are in dreamless sleep or “knocked out” by general anesthesia, it is not. (Where it “goes” during such times is a perennial topic of religious and philosophical speculation.) It has basic components that comprise it, such as colors, sounds, flavors, scents, the experience of pain and pleasure and emotions, and the sense of having (or being) a body. The soul  —  the “person in there”  —  is the same thing as consciousness or sentience. It exists. In fact, it is the only thing whose existence we can be absolutely sure of.

The Modern Secular Soul

While it may seem odd at first glance to drag a religious concept into science, we should recognize that the soul is not in fact a religious concept at all. Rather, it is merely an observed phenomenon which in ancient times was given religious explanations  —  just as the sun, the stars, the weather, the origins of the universe, and pretty much everything else was given religious explanations. The soul is no more inherently religious than any of these. And to openly discuss the science of the soul should be just as uncontroversial as discussing the science of planets, clouds, or the Big Bang.

Except, of course, it won’t be. Many religious persons will consider the notion of a secular soul blasphemous or merely nonsensical. Yet the entire history of science has been a story of thefts from religion, and each one has met resistance. Just ask Galileo.

By embracing the fact  —  and it is a fact  —  that the modern science of consciousness is studying the same phenomenon which religious descriptions of the soul have sought to explain, we can properly place our inquiries into the broader historical context, and facilitate an intuitive understanding of what we’re pointing at when we speak of consciousness. Not only is consciousness a long and awkward word to use for the soul, but it also has confusing baggage of its own. Dreaming is a conscious state, for example, and yet we commonly think of sleep as un-consciousness. And lingering post-Freudian notions of the “subconscious” in popular culture complicate things even further.

A Thing That Stops and Starts

A modern, scientific conception of the soul, as preliminary as it may be, answers many of the questions that have been debated for centuries:

• What is the soul? It is a bodily function, specifically a function of the brain.
• Is the soul immortal? Does it pre-exist birth? Does it survive death? Does it reincarnate? No. We should think of the soul as an activity rather than a thing, something the body does rather than something it has. Like digestion, circulation, and respiration, it has no existence apart from a living, functioning body. Quite frankly, it would be tremendously useful to have a verb form of the word.
• Do animal have souls? Yes, at least some animal brains do produce souls. While getting into the science of consciousness is beyond the scope of this article, it is almost certain that all mammal brains produce souls, and highly likely that the brains of birds do, as well. Insects, on the other hand, have nervous systems which are too simple to produce souls. Cephalopods? Their brains are so different from ours that we will need to discover much more about how consciousness is performed before venturing an answer there.
• Do plants have souls? No. Although our understanding of the mechanisms of consciousness is currently quite limited, we do know that it is a complex brain function. There are simply no analogous structures or functions within plants.
• Where does the soul go when we are asleep and not dreaming? Nowhere. It’s simply not being produced by the brain. Asking where it goes is like asking where running goes when we’re standing still. It’s a badly formed question.

Brain science reveals that the soul is something like an eddy in a stream. When I was a boy I used to spend hours playing in creeks, and I loved spotting tiny whirlpools and following them as they moved with the flow. At times, the water would run over a shallow bit, and the eddy would disappear, only to reappear on the other side. Until, eventually, it didn’t. Our souls are like that, things that stop and start, appearing when we wake in the morning, disappearing when we sleep, popping back into existence when we dream, and vanishing again when our dreams end, only to begin once more just before we open our eyes. Until eventually it doesn’t. It is our brains’ memory-function which gives us the sense of continuity, the feeling that each time our soul begins, it is still us. Whether each performance of the soul by a brain actually is the same soul, and for that matter whether the vortex on either side of the shallow part of the stream is the same eddy, is a question I will leave to the philosophers.

Defining Personhood

The battle over the fate of Terri Schiavo was always a battle about the soul, whether or not everyone involved would have chosen that exact word. Without a soul  —  without consciousness, without sentience, without that hologram-like-thing going on inside our heads  —  or the potential for our brains to once again produce it, we are not persons. We are merely bodies.

Accepting that the science of conscious experience is nothing more or less than a modern approach to understanding what philosophy and religion have called the soul (atma, dusza, etc.) allows us to address with clarity such questions as whether there really is a “person in there” after traumatic brain injury. And if we pretend that they are not the same thing, we perpetuate a dualism that doesn’t reflect reality. We do not pretend that the scientific study of stars is not a modern approach to what the ancient Aztecs attempted to explain by invoking the god Tōnatiuh. Why make an exception when it comes to the soul?

Header image by geralt