Full Idea
There can be a difference between our sensation of light and what is in the objects that produce that sensation in us.
Gist of Idea
Our sensation of light may not be the same as what produces the sensation
Source
René Descartes (The World [1631]), quoted by Ian Dunt - How to be a Liberal 1
Book Reference
Dunt,Ian: 'How to Be a Liberal' [Canbury Press 2020], p.18
A Reaction
Note only that they 'may' differ, and that he does not assert that they are entirely different. Secondary qualities give information, and are not just mental events.