Lecture 11 Notes

1. Background
1. Key Question: What Makes Something a Mental State?
2. Reductionism in Science
• Example: Water Is H₂0
3. Core Assumption: To Discover the Essence of Something, We Focus Upon Its Physical Composition
2. Central Claim: Mental States are Sefined By Virtue of Their Underlying Neurological Make-Up.  In Short, Types of Mental States are Simply Types of Brain States.
   
3. Virtues
1. No interaction problem.
2. No deep worries about other minds.
3. Makes psychology part of the natural sciences.  This has evolutionary and developmental plausibility.

Problems with Identity Theory

1. Appeals to Leibniz's Law
1. Minds and brains seem to have different properties.  Ex.  Mind is non-spatial.  Brain is spatial. 
   
2. Replies
• Question-begging; assumes the mind is non-spatial which is just what the argument is trying to prove.
• Look at Historical Analogues--Other reductions have occurred when at first it appeared that they had different properties.  Ex. Light can be reduced to electromagnetic waves.
2. Material Chauvinism
1. Martian Thought Experiment--If identity theory is true, pain is identical to a type of brain state in a carbon based organism.  Suppose that there are martians made of silicon.  According to identity theory, it would be impossible for them to be in pain because they are not carbon based.  But it seems reasonable to think that there is nothing special about being carbon based that makes humans capable of experiencing pain.
2. Brain Transplant Thought Experiment--If identity theory is true, pain is identical to a type of brain state in a carbon based organism.  Suppose that we develop a synthetic brain material to replace the brain material that is in the human brain.  According to identity theory, it would be impossible for this synthetic brain material to be in the brain state pain because it is not carbon based.  But it seems reasonable to think that we could still be in pain even with the synthetic brain material.
3. These thought experiments show that the stuff your brain is made of is not what is required to have a mental life so identity must be false.
4. Reply: Functionalist Materialism.  According to functionalist materialism, mental states are identical to functional roles.  For example, pain is whatever causes me to shout "Ouch!" when I touch a hot stove.  Now pain is not identified with the stuff that your brain is made of.