Mind: A Brief Introduction (John R. Searle) / quote 18 of 138
Causal interaction between mind and body
What exactly are the relations between the mental and the physical, and in particular how can there be causal relations between them? It seems impossible that there should be causal relations between two completely different metaphysical realms, the physical realm of extended material objects and the mental or spiritual realm of minds or souls. How does anything in the body cause anything in the mind? How does anything in the mind cause anything in the body? Yet, it seems we know that there are causal relations. We know that if somebody steps on my toe, I feel a pain even though his stepping on my toe is just a physical event in the physical world, and my feeling of pain is a mental event that occurs inside my soul. How can such things happen? Just as bad: it seems there are causal relations going the other way as well. I decide to raise my arm, an event that occurs inside my conscious soul, and, lo and behold, my arm goes up. How are we supposed to think that such a thing could ever happen? How can a decision in my soul cause a movement of a physical object in the world such as my body? This is the most famous problem that Descartes left us, and it is usually called the “mind-body problem.” How can there be causal relations between the two? Much of the philosophy of mind after Descartes is concerned with this problem, and it is still, in spite of all of our progress over the centuries, a leading problem in contemporary philosophy.