Full Idea
Abstraction principles purport to introduce fundamental means of reference to a range of objects, to which there is accordingly no presumption that we have any prior or independent means of reference.
Gist of Idea
Equivalence abstraction refers to objects otherwise beyond our grasp
Source
B Hale / C Wright (The Metaontology of Abstraction [2009], §8)
Book Reference
'Metametaphysics', ed/tr. Chalmers/Manley/Wasserman [OUP 2009], p.195
A Reaction
There's the rub! They make it sound like a virtue, that we open up yet another heaven of abstract toys to play with. As fictions, they are indeed exciting new fun. As platonic discoveries they strike me as Cloud-Cuckoo Land.