Mind/Brain Interaction

One of the major objections to the notion that we possess an immaterial mind that somehow works in concert with our material brain is that interaction between two radically different substances is incomprehensible. We can comprehend how one material thing can interact with another because we see it all the time, the materialist says, but how can an immaterial thing like mind cause an effect in a material thing like a brain?

Since the dualist cannot explain how this is possible her belief in mind/brain interactionism is thereby believed to be discredited.

As physicist Stephen Barr once pointed out in a book review in the January 2010 issue of First Things, however, few who pose this objection to dualism stop to ask how it is that anything interacts with anything else.

The materialist (one who believes that matter is all there is) assumes that matter can interact with matter, but if you ask a materialist to actually explain the interaction you draw a blank.

The same explanatory problem confronting the dualist confronts the materialist whenever he tries to understand how two material objects interact or how a force like magnetism interacts with steel, or how matter interacts with space. We simply don't know how these phenomena take place.

Barr writes:

Material bodies are made up of electrically charged particles that interact with each other through the mediation of electromagnetic fields: The charged particles affect the fields and the fields affect the particles. By what "means" or "mechanism" this happens physics does not say.

It simply says that when electromagnetic fields are present, the charges are, in fact, affected as described by a certain equation; and when the charges are present the fields are affected as described by another equation.

In other words, physics posits two types of entities and mathematically describes, but does not otherwise explain, their influence on each other.

Nor is neuroscience much help in resolving the mystery:

[Neuroscience] can tell us that a lower than normal concentration in the brain of a molecule called dopamine (a certain arrangement of eight carbons, eleven hydrogens, one nitrogen, and two oxygens) leads to the subjective experience of boredom or apathy.

It can find that the electrical stimulation of a certain tiny region of the brain produces mental states ranging from mild amusement to hilarity. It can report ... that “damage to a certain small area of the cortex serving vision (called ‘V4’) can strip color” from one’s visual experiences.

But in none of these cases can it explain the connection between motions of material particles and mental experiences...

Gravity poses the same problem. We have no idea how gravity "pulls" objects toward a massive body, or, for that matter, how a massive body produces gravity in the first place, or even what gravity is.

If we fall back on the Einsteinian explanation that gravity is simply the bending of space around a material object then we've simply pushed the problem back a step. How, it can be asked, do material bodies bend space? If space is essentially "nothing" how is it affected by a "something" in its midst?

The materialist has no answer, but that doesn't stop him from believing it nor from disparaging the dualist for thinking that mind and brains interact. Pretty ironic, don't you think?