Full Idea
If a mental property is realised by a material property, then it looks as though its material realiser pre-empts any causal contribution on the part of the realised mental property.
Gist of Idea
If minds are realised materially, it looks as if the material laws will pre-empt any causal role for mind
Source
John Heil (Philosophy of Mind [1998], Ch.6)
Book Reference
Heil,John: 'Philosophy of Mind' [Routledge 1998], p.198
A Reaction
This has a beautiful simplicity about it. I can see how some very odd phenomena might suddenly appear out of a physical combination, but not how entirely new causal laws can be created.