Full Idea
All general ideas are nothing but particular ones, annexed to a certain term, which gives them a more extensive signification, and makes them recall upon occasion other individuals, which are similar to them.
Gist of Idea
General ideas are the connection by resemblance to some particular
Source
David Hume (Enquiry Conc Human Understanding [1748], I.VII.17), quoted by Edwin D. Mares - A Priori 08.2
Book Reference
Mares,Edwin: 'A Priori' [Acumen 2011], p.125
A Reaction
This is close to Berkeley's idea that we can only grasp particulars. Personally I think the idea of (psychological) abstraction is unavoidable. Irrelevant features of particulars need to ignored.