The problem with Dualism, is that we have no way of determining the communication mechanism by which the non-physical part of the mind affects the physical part of the brain, so it is unlikely that one exists at all. If no communication gateway exists between a particular mind and a particular body, then it is almost impossible to say that Dualism can be correct.
I think that comprehending the non-physical part is just as hard as comprehending the communication gateway. In other words, if you can comprehend one, you can probably comprehend the other.
