Full Idea
Plurals earn their keep in set theory, to answer Skolem's remark that 'in order to treat of 'sets', we must begin with 'domains' that are constituted in a certain way'. We can speak in the plural of 'the objects', not a 'domain' of objects.
Gist of Idea
We can use plural language to refer to the set theory domain, to avoid calling it a 'set'
Source
Oliver,A/Smiley,T (What are Sets and What are they For? [2006], Intro)
Book Reference
'Metaphysics (Philosophical Perspectives 20)', ed/tr. Hawthorne,John [Blackwell 2006], p.125
A Reaction
[Skolem 1922:291 in van Heijenoort] Zermelo has said that the domain cannot be a set, because every set belongs to it.