The Decade of the Brain
Advancements in neuroscience were soon forthcoming after George H.W. Bush pronounced the 1990s as the decade of the brain. Since then new brain-related discoveries have been (and are continuing to be) shaped into an overall narrative that the mind and the brain are identical. Due to these advancements, theologian Nancey Murphy writes, “neuroscience has in a sense completed the Darwinian revolution, bringing not only the human body but the human mind as well, into the sphere of scientific investigation.” In other words, since the mind is the brain, science can explain thoughts and behaviors as mere neuronal activity.
As a substance dualist, I will attempt a cumulative case for showing that the mind cannot be identical to the brain. Please note, these arguments will trade on a couple of factors: 1) if it can be shown that the mind is not identical to the physical brain, then the mind is an immaterial substance; 2) If it can be shown that the mind is immaterial then human beings have souls.
Our Sustained Identity
There is a fundamental problem at the heart of suggesting that we are a physical body and nothing more; that is, our body keeps changing. Think of it this way: Let’s say Joseph is 5’9” at age 32 whereas his body was only 4’9” at age 12. The cells at all levels in his body have been replaced various times over in his life such that his body is entirely different than the way it was at age 12. And yet Joseph, the person, retained his identity throughout the entire process. There was no partial Joseph or a degree of a Joseph. He was fully Joseph at every moment of his life. The physicalist who holds that the mind is identical to the body cannot adequately explain: 1) why there is a unified center of experience otherwise known as an enduring “I”; and 2) why this enduring “I” remains the same even though the body’s parts continue to change.
Intentionality of the Mind
Our minds possess intentionality; that is, we have the ability to make choices based on purposes. So, for example, I am writing this post for the purpose of giving good reasons for the soul’s existence. But, if a neuroscientist were to look into my brain at the moment of this writing, my brain states would not be for or about anything. That is because no physical state of my brain has intentionality. Physical objects, like brains, “can stand in various physical relations with other physical objects… But one physical thing is not of or about another one.” Think of it this way: If Ron Burgundy was trying to sell an SUV his thought would be about the vehicle. But if a wooden podium were to stand next to an SUV, it would not be about the vehicle at all. Physical objects, like podiums and brains, cannot be about other objects; only thoughts can. And, since the mind has thoughts, it cannot be identical to the brain.
Subjective Quality of the Mind
In 1974 Thomas Nagel wrote an article entitled “What Is It Like to be a Bat?” proving that a subjective quality of the mind exists that cannot be scientifically measured. His argument can be explained this way: Imagine the future where a leading expert on the neurology of hearing also happens to be deaf. Due to the advanced neuroscience of his time, the expert knows every physical fact about the brain pertaining to the act of hearing. Suppose this expert, one day, began to hear for the first time. He would learn brand new facts that he never knew before. Nagel describes this new knowledge as the “what it is like” to hear. The philosophical implications for this are devastating. Since the expert has now learned new facts (even though he knew every physical fact about the act of hearing) then it follows that these new facts are mental facts. Since these mental facts are not identical to physical facts then the mind is not identical to the brain.
Remember: If it can be shown that the mind is immaterial then human beings have souls. I believe these arguments are sufficient to build a cumulative case for the existence of an immaterial substance apart from our physical bodies. Therefore, the question you must ask is: Which worldview (that is, the physicalist or the substance dualist) has the better explanation for our mental experiences?
 Nancey Murphy, “Human Nature: Historical, Scientific, and Religious Issues,” Whatever Happened to the Soul?: Scientific and Theological Portraits of Human Nature, eds. Warren S. Brown, et. al (Minneapolis: Fortress Press, 1998), 1.
 Since, by definition, the soul is the immaterial aspect of a human being.
 J.P. Moreland and William Lane Craig, Philosophical Foundations for a Christian Worldview (Downers Grove: InterVarsity Press, 2001), 237.