Conclusion

So the physicalist's part is it depends on the brain. But here's the non-reductive part in a nutshell:  Those mental constructions that involve language make a real causal difference in the world.  We can see that this is true.  Laws make human beings behave differently than they would have otherwise. Belief in God results in different behavior.  And it even results in there being different physical objects in the world than there would have been in the world without it.  For example, you can think of churches as monuments to--if nothing else--the causal efficacy of belief in God.

In my next lecture, what I'm going to try to do is put all of these pieces together with a concept of the downward causation of the mental in order to reconcile the notion of mental causation and free will with neurobiological causation.  But I stop here and I have saved you 20 minutes to ask me questions.