In 1968 I lost my father to cancer. I was four years old. I can still remember the funeral home. And I can remember that as I looked into the casket, my mother told me that my father was now with God in heaven. I remember feeling perplexed. And why not? My father was lying lifeless before me. How could he be with God in heaven? I came to understand that my mother believes what most Christians have believed down through the centuries: humans are immaterial souls capable of disembodied existence.
Try as I might, I cannot bring myself to believe what my mother, and most Christians, believe about human nature. It's not that I don't understand the view. I do. It's not even that I believe, as is all the fashion these days, that dualism is responsible for everything from the oppression of women to the pillaging of the environment. It's not. And I do believe that some kinds of persons are immaterial—non-human, divine persons like God and the angels, for example. What I deny is that that human persons like you and me are immaterial.
There are, as you might imagine, different versions of dualism. For example, there is a Thomistic version of dualism (owing to Saint Thomas Aquinas) and an emergent version (most rigorously defended by William Hasker). And then there is the good old-fashioned dualism of Descartes and Augustine. According to them, the natural world is home to two radically different kinds of things—immaterial, thinking things (souls) and unthinking, material things (bodies). We—thinking things that we are—are immaterial souls. Thomistic dualism, in contrast, asserts that you and I are compounds of body and soul, or more accurately, form and matter, while "emergent" dualism claims that while you and I are in fact immaterial souls, our souls emerge naturally through the course of ordinary, biological evolution. They are natural, not introduced or added "from the outside" so to speak. I reject dualism in all its versions. Here's why.
If persons (or souls) and bodies are as distinct as Descartes and Saint Augustine thought them to be, then I wouldn't expect to find the level of dependence of the one (the mind/soul) on the other (the body/ brain) that we in fact do find. Take Clive Wearing, for example.
Clive is a 66-year-old former composer and musician who has completely lost the ability to lay down new, conscious memories. For the past twenty years he has lived in a tragic and perpetual state of "just waking up." Whether his wife has been gone for ten minutes or ten years, it doesn't matter: when she enters his room he embraces her ecstatically, believing that he is seeing her for the first time after a long separation. Several minutes into a game of solitaire, a game which he loves, he will have no recollection that it was he who dealt and played the cards lying before him. Even when he records copious notes for himself on the progression of the game, he will still insist that, although the notes are indeed in his handwriting, he did not write them. He claims that he has no idea how the notes got there or who may have dealt the cards. Imagine that—your whole conscious life lived out on a mental treadmill; no matter how far you run it is always the same well-worn path you travel.1 That's the character of Clive Wearing's conscious life—his sense of being a continuous self stretches no farther back than just a few minutes.
What is the cause of Clive Wearing's severe and unusual form of amnesia? Clive's amnesia is the result of a viral infection that insinuated itself into his brain, completely destroying his hippocampus, that part of the human brain responsible for storing conscious memories. That consciousness can be altered or even eliminated by altering or destroying certain regions of the brain demonstrates the degree to which our mental lives are radically physically based. My argument is not that soul/body dualism is logically incompatible with empirical discoveries in the neurosciences. My argument is simply that if we were immaterial souls, we wouldn't expect to find such a radical, causal dependence of the mental on the physical.






