Let composite substance dualism be the doctrine that I am composed of two distinct substances: my soul and my body. I find compelling the following argument, though I think my opponents will simply deny premise 1.
- I am only agentially responsible for an event E if I non-derivatively cause E.
- If composite substance dualism is true, everything I cause is caused by me derivatively from causation by my soul and I am not my soul.
- If materialism is true, everything I cause is caused by me derivatively from causation by proper parts of me (e.g., particles, neurons) and/or things outside of me (e.g., fields).
- So, if materialism or composite substance dualism is true, I am not agentially responsible for any event.
- But there are events are I am agentially responsible for.
- So, composite substance dualism and materialism are false.