Full Idea
There are tools like a hammer used by one person, and there are tools like a steamship which require cooperative activity; words have been thought of too much on the model of the first sort of tool.
Gist of Idea
Language is more like a cooperative steamship than an individual hammer
Source
Hilary Putnam (Meaning and Reference [1973], p.156)
Book Reference
'Meaning and Reference', ed/tr. Moore,A.W. [OUP 1993], p.156
A Reaction
This clear thought strikes me as the most fruitful and sensible consequence of Wittgenstein's later ideas (as opposed to the relativistic 'language game' ideas). I am unconvinced that a private language is logically impossible, but it would be feeble.