Full Idea
Primary properties describe the substance as it is in and by itself; secondary properties underlie the impact of substances upon others and the responses they invoke from them.
Gist of Idea
Primary properties describe what it is; secondary properties underlie the impact and responses
Source
Nicholas Rescher (Process Metaphysics [1996], 2.6)
A Reaction
A good summary of secondary qualities. If we are to explain the secondary 'impact' (though not the response), then we must use the primary to explain the secondary.
Book Reference
Rescher,Nicholas: 'Process Metaphysics' [SUNY 1996], p.47