Full Idea
The argument that works of art have properties that physical objects could not have characteristically concentrates on the expressive properties of works of art.
Gist of Idea
It is claimed that the expressive properties of artworks are non-physical
Source
Richard Wollheim (Art and Its Objects [1968], 10)
Book Reference
Wollheim,Richard: 'Art and Its Objects' [Penguin 1975], p.28
A Reaction
Since the idea of an object having non-physical properties strikes me as ridiculous, this gets off to a bad start. If artworks are abstract objects, then all of their properties are non-physical.