Full Idea
If qualia are non-functionally defined objects, then their attachment to their role in my thought would seem to be metaphysically accidental.
Gist of Idea
If qualia have no function, their attachment to thoughts is accidental
Source
Georges Rey (Contemporary Philosophy of Mind [1997], 11.4.2)
Book Reference
Rey,Georges: 'Contemporary Philosophy of Mind' [Blackwell 1997], p.300
A Reaction
A rock at sea can cause a shipwreck without being defined as 'a shipwrecker'. It is, of course, tautological that if qualia have a 'role' in my thoughts, they must have causal powers, but 'function' is a much trickier concept.