Is thinking a physical process, or is it spiritual?
I believe that the answer is that thinking is both physical and “spiritual.”
One thing we can be sure of is that thinking is a physical process. This has been shown by experiment and our experience agrees with experiment. MRI (magnetic resonsance imaging) experiments have shown how different parts of the brain have chemical and electrical activity which corresponds to thought. Different kinds of thought processes light up different parts of the brain. Anger finds itself in one place, rational analysis another, and fear still another place in the brain. When we are thinking, brain wave patterns corresponding to those thoughts happen and neurons fire in somewhat predictable ways as that thought is happening. Besides, our common experience tells us that thinking is physical. When we think hard and long we get headaches and we get physically tired. Thinking can be exhausting, which proves that thinking is a physical thing.
Of course, it is much more difficult to “prove” that there is a non-physical aspect of thinking. How can we “prove” this using physical tests when, by its very nature, a spiritual thing cannot be measured? I have two arguments I would like you to consider that thinking is not merely neurons firing and neurotransmitters being released.
First of all, the Bible, which I believe is inspired by the Creator of the universe–God tells us that thought is a spiritual activity (although I suppose those exact words are never used). The Bible treats us as people who have both a physical and a spiritual nature. I could demonstrate this with literally hundreds of biblical passages. I will use Ephesians 6:12, “For our struggle is not against flesh and blood, but against the powers… in the heavenly realms. Our thoughts are spiritual, they engage spiritual things, and those things are not “flesh and blood.” They are not physical. When we are baptized into Christ we receive the Holy Spirit to live in us (Acts 2:38-39) and this Spirit is not a physical thing. When we pray, the Holy Spirit helps us, and this involves non-physical help. Love is not mere firing of neurons and the release of chemicals in the brain. We have a soul and a spirit, and these things are not physical. Consider two possibilities: I am a body or I have a body. Nearly all of us will agree that we have a body, which means we believe we exist apart from our body. In other words there is an “us” which is not a physical thing. This does not constitute proof that thinking is, in part, non-physical, but I believe that it is a compelling argument.
Then there are other facts about us which imply to me a reality higher than the mere physical. What is memory? Why and how is it that we can apparently remember literally millions of words and musical notes we have heard and virtual images of things in our lives. How many bits of information are contained in a single memory, given that we have actual images from the past? The amount of “information” which is stored in our memories, if we take into account all the sound, smell, taste, video, words, etc. would amount to information many many orders of magnitude greater than all the neurons in our brains. Where are these memories stored? Which neurons hold this information and how? To require that our existence as conscious beings and our memories are contained fully in a physical brain violates common sense and the physical reality of our brains. This, too, argues that there is a non-physical dimenstion to us, to our self-consciousness, to our memories and, apparently, to our thoughts.
Here is how I have thought about the mind/brain connection. I am a mild dualist. Descartes said, “I think, therefore I am.” He argued that there is a brain but that we exist apart from our bodies. I believe he went to far in nearly completely separating self from body. I believe that in God’s wisdom he created a wonderful synthesis of mind and body. I describe our brains as extraordinary God-experiencing machines. Our brains are essentially an interface between the spiritual reality and the physical world. Spiritual activities activate physical processes. There is a one-to-one correlation between self and body in my opinion. This is a bit speculative. It cannot be “proved” by science, and I cannot give a scripture to prove that this idea is biblical, but it is how I have come to think of mind/body/thought. I am cc’ing my friend John Beggs who does research in neuroscience in case he wants to add his own release of neurotransmitters to the mix.