Full Idea
The set theorist cannot tell us anything about the true relationship of membership.
Gist of Idea
The set theorist cannot tell us what 'membership' is
Source
Charles Chihara (A Structural Account of Mathematics [2004], 01.5)
Book Reference
Chihara,Charles: 'A Structural Account of Mathematics' [OUP 2004], p.24
A Reaction
If three unrelated objects suddenly became members of a set, it is hard to see how the world would have changed, except in the minds of those thinking about it.