Full Idea
The primary qualities are the object of the mathematical sciences.
Gist of Idea
Primary qualities are the object of mathematics
Source
Thomas Reid (Essays on Intellectual Powers 2: Senses [1785], 17)
Book Reference
Reid,Thomas: 'Inquiry and Essays', ed/tr. Beanblossom /K.Lehrer [Hackett 1983], p.184
A Reaction
He spells out this crucial point, which is not so obvious in Locke. The sciences totally rely on the primary qualities, so it is ridiculous to reject the distinction (which Reid accepts).