Full Idea
Whatever the causal process is, it remains true that if emergentism is true, the completeness of physics is false; there are some effects which would not have come about if mental things were absent from the world.
Clarification
'Emergent' properties are not a necessary consequence of their physical basis
Gist of Idea
If mental properties are emergent they add a new type of causation, and physics is not complete
Source
Tim Crane (Elements of Mind [2001], 2.18)
Book Reference
Crane,Tim: 'Elements of Mind' [OUP 2001], p.65
A Reaction
Emergentism looks to me like an incoherent concept, unless it is another word for dualism.