Full Idea
Secondary qualities are not distinct from primary qualities: an object's possession of a given secondary quality is a matter of its possession of certain complex primary qualities.
Gist of Idea
Objects only have secondary qualities because they have primary qualities
Source
John Heil (From an Ontological Point of View [2003], 17.3)
Book Reference
Heil,John: 'From an Ontological Point of View' [OUP 2005], p.200
A Reaction
The bottom line here is that, if essentialism is right, colours are not properties at all (see Idea 5456). Heil wants to subsume secondary properties within primary properties. I think we should sharply distinguish them.
Related Idea
Idea 5456 Redness is not a property as it is not mind-independent [Ellis]