Full Idea
My concept of an elm tree is exactly the same as my concept of a beech tree (I blush to confess), which shows that the determination of reference is social and not individual - both you and I defer to experts who can tell elms from beeches.
Gist of Idea
Reference is social not individual, because we defer to experts when referring to elm trees
Source
Hilary Putnam (Reason, Truth and History [1981], Ch.1)
Book Reference
Putnam,Hilary: 'Reason, Truth and History' [CUP 1998], p.18
A Reaction
If I said 'that tree looks nice' I wouldn't be deferring to experts. Nor if I said 'that tree, which I take to be an elm, looks nice'. If I am an expert I don't defer to experts.