- If it is conceivable that p, then it is possible that p.
- It is conceivable that p.
- (Therefore) It is possible that p.
- The possibility of zombies is taken as conclusive evidence against physicalism.
- The possibility of multiple realizability is taken as conclusive evidence against mind-body identity theories.
Descartes, of course, realized this, and so, in his conceivability argument, there is a step from mere possibility to actuality (even though it ultimately fails). This step is the following:
I know that everything which I clearly and distinctly understand is capable of being created by God so as to correspond exactly with my understanding of it.So, Descartes' conceivability argument looks something like this:
- I can conceive of the mind as separate from the body.
- If I can conceive of the mind as separate from the body, then God could have created the mind without the body.
- (Therefore) God could have created the mind without the body.
Nowadays, some dualists might be reluctant to appeal to God in support of their theories. So, can the gap in conceivability arguments be bridged?