Critcism 1 - Searle is a interactionist Property Dualist, and therefore we can use criticisms of property dualism against him. Mainly causal - overdeterminism, which suggests that, the versitility of the causal methods between brain states and mental states means that certain brain states and mental states have too many causal paths to get to them.

Response 1 - Why I am not a property dualist. Searle believes in different levels of description, but not different levels of properties. There is a similarity in terms of irreduceable consciousness. However, Searle says that mental states are CAUSALLY reduceble to brain processes.Consciousness does not a distinct, separate phenomenon, something over and above its neurobiological base, rather it names a state that the neurobiological system can be in.

Response 2 - Futhermore, even if I am a property dualist, there are ways of escaping over-determination for example, the brain state and the mental state (MB) occur SIMULTANEOUSLY, and merely the next brain state and mental state (M*B*) occur in the next frame of time.   

MB —-> M*B*

NOT

M —-> M*

^        ^

B —-> B*