Full Idea
If language is to be a means of communication there must be agreement not only in definitions but also (queer as this may sound) in judgments.
Gist of Idea
To communicate, language needs agreement in judgment as well as definition
Source
Ludwig Wittgenstein (Philosophical Investigations [1952], §242)
Book Reference
Wittgenstein,Ludwig: 'Philosophical Investigations', ed/tr. Anscombe,E. [Blackwell 1972], p.88
A Reaction
If someone is locked into a highly alien viewpoint, then communication with them does seem to be virtually impossible. Amenability to reason, and consensus on elementary facts, seems to be the sine qua non of communication.