Full Idea
What is property dualism but the view that there are irreducible mental properties?
Clarification
Just as being red and square are separate properties
Gist of Idea
Property dualism denies reductionism
Source
John Searle (The Rediscovery of the Mind [1992], Ch. 5.III)
Book Reference
Searle,John R.: 'The Rediscovery of the Mind' [MIT 1999], p.118
A Reaction
Being red and being square are separate, but they are both entailed by the material basis, and hence are reducible. Properties may not link directly, but they must link indirectly.