Consider the following statement: “My liver believes materialism is true.”
Sheer lunacy, right? But on materialism, there is no fundamental difference between the brain and the liver. They are both just meat. Therefore, for the materialist, the phrase “my brain believes materialism is true” is equivalent to the phrase “my liver believes materialism is true.”
The materialist really is stuck. Objects like the liver do not have belief states. Philosophers say they do not exhibit “intentionality” (the “aboutness” a subject has towards an object). A rock cannot have a belief about the proposition “materialism is true.” Neither can a liver. Neither can a brain. Thus, the very act of affirming materialism denies one of its fundamental tenants because the act of affirming necessarily requires intentionality.
But I can hear the materialist object, the human body is a system which is greater than any of its individual components like the brain and the liver alone. It still does not work, because on materialism, each human is reducible to the chemical components of his body. Therefore, the body is nothing but a complex amalgamation of chemicals, and the statement “complex amalgamation of chemicals believes materialism is true” gets the materialist no further than “my liver believes materialism is true.”
Materialism requires its proponents simultaneously to hold the following contradictory beliefs:
1. A material object cannot have a belief state.
2. A brain has belief states even though it is just another kind of material object.
A metaphysical system that requires its proponents to hold mutually exclusive propositions simultaneously should be rejected. Our materialist friends can have logic and reason or they can have their materialism. They can’t have both.